EPA 660/2-74-006
APRIL 1974
                       Environmental Protection Technology Series
  Wastewater  Abatement  in Canning
   Vegetables  by IQB Blanching
                                Office of Research and Development
                                U.S. Environmental Protection Agency
                                Washington, D.C. 20460

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             RESEARCH REPORTING SERIES
 Research reports of the  Office  of  Research   and
 Monitoring,  Environmental  Protection Agency, have
 been grouped into five series.   These  five  broad
 categories  were established  to facilitate further
 development  and  application   of   environmental
 technology.   Elimination   of traditional grouping
 was   consciously  planned   to  foster   technology
 transfer   and  a  maximum  interface  in  related
 fields.   The five series are:

   1.  Environmental Health Effects Research
   2.  Environmental Protection Technology
   3.  Ecological Research
   4.  Environmental Monitoring
   5.  Socioeconomic Environmental Studies

 This report has been assigned to the ENVIRONMENTAL
 PROTECTION   TECHNOLOGY   series.    This   series
 describes   research   performed  to  develop  and
 demonstrate   instrumentation,     equipment    and
 methodology  to  repair  or  prevent environmental
 degradation from point and  non-point  sources  of
 pollution.   This work provides  the new or improved
 technology   required for the control and treatment
 of pollution sources to meet environmental quality
 standards.
                   EPA REVIEW NOTICE
This report has been reviewed by the Office of Research and
Development, EPA, and approved for publication. Approval
does not signify that the contents ncesssarily reflect the
views and policies of the Environmental Protection Agency,
nor does mention of trade names or commercial products consti-
tute endorsement or recommendation for use.

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                                               EPA-660/2-74-006
                                               April  1974
        WASTEWATER ABATEMENT IN CANNING VEGETABLES

                     BY  IQB  BLANCHING
                             By

                        Daryl  B.  Lund
                   University of Wisconsin
                     Madison, Wisconsin
                    Grant No.  S-801484
                   Program Element 1BB037
                       Project Officer

                    Mr.  Harold Thompson
    Pacific Northwest  Environmental Research Laboratory
                 Corvallis, Oregon  97330
                        Prepared for
            OFFICE OF  RESEARCH AND DEVELOPMENT
           U.S. ENVIRONMENTAL PROTECTION  AGENCY
                  WASHINGTON, D.C.  20460
For sale by the Superintendent or Documents, U.S. Government Printing Office, Washington, D.C. 20402 - Price $1.25

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                                   ABSTRACT

This report presents the results of a study on the efficacy of a new blanching
system, Individual Quick Blanch (IQB), as applied to vegetables prior to
canning.  Peas, corn, lima beans,  green beans, potatoes, carrots and beets
were adequately blanched by IQB.  Compared to deep bed steam blanching or pipe
blanching, IQB generally resulted in a significant reduction in effluent.
Slight drying of the vegetables before IQB reduced effluent even more; how-
ever, product quality was adversely affected in most cases.  It was demon-
strated that the IQB process can significantly reduce effluent volume and BOD
generation in the blanching operation while adequately fulfilling the objec-
tives of blanching.  Commercial application of IQB appears economically
favorable.

This report was submitted in fulfillment of Project Number S-801484, by
Daryl Lund, University of Wisconsin, under the partial sponsorship of the
Environmental Protection Agency.  Work was completed as of August 1973.
                                       ii

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                              CONTENTS




                                                                   Page




Abstract                                                           ii









List of Tables                                                     iv




Acknowledgments                                                    vi




Sections




I       Conclusions                                                 1




II      Recommendations                                             2




III     Introduction                                                3




IV      Objectives                                                  7




V       Materials and Methods                                       8




VI      Results and Discussion                                     18




VII     Units  for Interconversion of Data                          56




VIII    References                                                 58




IX      List of Publications                                       60




X      Appendix—Raw Data                                         61

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                               TABLES

No.                                                              Page

1      Product Forms and Processing Dates                        9

2      Blanching Methods                                         10

3      Blanching Times and Temperatures                          15

4      Product Evaluation Tests

5      Hourly Make-up Water Flow Rates and Total Solids          20
       Content of Pipe Blancher Water for Peas, Corn, Lima
       Beans and Green Beans

6      Summary of Pea Blanching Data                             23

7      Summary of Objective Evaluation of Peas                   27

8      Summary of Subjective Evaluation of Peas                  29

9      Summary of Corn Blanching Data                            30

10     Summary of Objective Evaluation of Corn                   31

11     Summary of Subjective Evaluation of Corn                  33

12     Summary of Lima Bean Blanching Data                       34

13     Summary of Objective Evaluation of Lima Beans             36

14     Summary of Subjective Evaluation of Lima Beans            37

15     Summary of Green Bean Blanching Data                      38

16     Summary of Objective Evaluation of Green Beans            41

17     Summary of Subjective Evaluation of Green Beans           42

18     Summary of Potato Blanching Data                          42

19     Summary of Objective Evaluation of Potatoes               44

20     Summary of Subjective Evaluation of Potatoes              45

21     Summary of Beet Blanching Data                            46
                                 iv

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                               TABLES




No.                                                              Page




22     Summary of Objective Evaluation of Beets                  49




23     Summary of Subjective Evaluation of Beets                 50




24     Summary of Carrot Blanching Data                          51




25     Summary of Objective Evaluation of Carrots                52




26     Summary of Subjective Evaluation of Carrots               52




27     Estimated IQB Production Units                            56




28     Factors for  Interconversion of Data                       57




29     Canning Yield Factors                                     58

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                               ACKNOWLEDGMENTS
The cooperation and support of this project by the Oconomowoc Canning Company,
Oconomowoc, Wisconsin, is acknowledged with sincere thanks.  Personnel at the
Sun Prairie and Waunakee Plants provided valuable assistance.

Partial financial support was provided by the Wisconsin Canners and Freezers
Association and their contribution is gratefully acknowledged.

The IQB blanching unit was supplied by the Western Regional Research Labora-
tory, USDA, Berkeley, California.  Obviously, without their support this
project would not have been possible.

Thanks is also extended to the Hughes Company, Columbus, Wisconsin, for
supplying some of the equipment required in this project.

A special thanks is extended to the Water Quality Laboratory, Wisconsin State
Department of Natural Resources, Madison.  This laboratory performed most of
the water quality tests and thus provided the bulk of the raw data in this
report.

Finally, acknowledgment is extended to personnel in the Department of Food
Science who contributed to the successful completion of this project.  Special
thanks goes to the personnel of the Sensory Evaluation Laboratory and the
taste panel members.
                                      vi

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                                  SECTION I
                                 CONCLUSIONS
Conventional blanching operations result in the generation of high volume,
high strength waste streams.  The efficacy of a new blanching system, Indi-
vidual Quick Blanching, was assessed with the objective of significantly re-
ducing blanching effluent while maintaining product quality.  IQB was applied
to peas, corn, lima beans, green beans, potatoes, beets and carrots prior to
canning.

IQB was found suitable for blanching vegetables prior to canning.  Effluent
generation was significantly reduced for peas, corn, lima beans and green
beans compared to pipe blanching and deep bed steam blanching.  Product quality
tests indicated that IQB blanched, canned products were as good as pipe
blanched, canned products.  For potatoes, beets and carrots, IQB could be
effectively used to inactivate peroxidase while minimizing inequity of heat
treatment received by the surface and center of the product.

Slight drying of the product prior to IQB further reduced blancher effluents.
However, generally canned product quality was adversely affected by this pre-
treatment.

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                                  SECTION II
                               RECOMMENDATIONS
This study was limited to a pilot plant evaluation of the individual quick
blanching (IQB) system.  It successfully demonstrated the potential of reduc-
ing canning plant effluent through the use of IQB.  Peas, corn, lima beans,
green beans, potatoes, carrots and beets were adequately blanched by IQB and
product quality was in most cases as good as the conventionally blanched-
canned product.

The next step for the development of IQB as a commercially viable blanching
system would be the design and installation of a full size production unit.
For that purpose, information contained in this report and in other published
papers on IQB could be utilized for providing design parameters (loading rates
and residence times).

If a private company or food equipment manufacturing company does not under-
take the development of a commercial IQB unit, it is recommended that EPA seek
a participant for a demonstration grant.  Preferably a company with both
freezing and canning facilities would undertake the project since the full
potential of IQB as a blanching method could then be evaluated.

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                            SECTION III
                            INTRODUCTION
GENERAL
     Upgrading and maintenance of  the environment is a major priority
     of government and private sector action.  For the solution to the
     environmental problems, research and development activities are
     directed in  three major areas:  (1) identification of major pollu-
     tion input from  industrial and other sources, (2) development of
     alternative  processes which eliminate or reduce effluent streams,
     and  (3) development of effective, economically feasible utiliza-
     tion or treatment of waste material.  In connection with these
     three activities, it was recognized that the food processing indus-
     try needed considerable effort.  Although the food industry has
     advanced technologically in the conversion of raw agricultural
     products to  consumer-acceptable products, little attention has been
     given to use of water and generation of high strength, large volume
     waste streams.

     Waste management within food processing has several distinctive
     characteristics which do not allow the direct adaptation of prac-
     tices used in other industries.  First, processing of fresh agri-
     cultural plant material into consumer products is generally sea-
     sonal in nature resulting in an uneven demand for treatment facili-
     ties.  This has created difficulties since it requires that the
     food plant either have its own treatment facilities which are used
     sporadically or that the food plant discharge its waste into

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     municipal or other treatment facilities  creating unusual  peak
     demands.   In either case,  waste treatment problems are somewhat
     unique.

     Second,  the composite waste stream generated in the food  processing
     plant is  usually a high volume, relatively low strength stream.
     This results from the fact that water is required in nearly all
     unit operations in food processing and usually little effort is
     made to  segregate streams  based on organic strength.
BACKGROUND
     Recent research activity designed to aid the food processing in-
     dustry has centered on identifying those unit operations where high
     strength, high volume waste streams are generated and development
     of technology resulting in reduction of waste generation at those
     unit operations.  Receiving considerable attention has been the food
     canning industry.  In the conversion of raw agricultural product to
     shelf-stable canned products, waste streams of significant volume
     and strength are generated per unit of product.  Analysis of the
     individual unit operations in canning indicates that the unit opera-
     tion blanching (sometimes referred to as scalding) is a major source
     of effluent .  With identification of a major pollutional source,
     considerable research effort has been directed toward development
     of effective, economically feasible blanching operations.

     The blanching operation fulfills several necessary functions includ-
     ing removal of tissue gases; inactivation or activation of enzymes,
     reduction of microbial load, cleansing of product, wilting of tissue
     to facilitate packing, and elevation of product temperature going
     into the retort.  Currently, the food industry uses both hot water
     and steam for blanching.  Both methods produce liquid wastes high
     in biochemical oxygen demand (BOD) and volume, and both result in
     loss of water soluble nutrients.  Based on data reported by Weckel

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et al.  for two Wisconsin canning plants, a 90% reduction in blancher
effluent would reduce total plant waste flow by 10 to 20% and, more
significantly, reduce total plant BOD by 20 to 50%.  The National
                   2
Canners Association  estimated that if a new blanching method which
reduced waste water strength by 5070 were used for the seven vege-
tables processed in the largest tonnage, a total of approximately 32
million kg.  (70 million pounds) of BOD and 18 million kg. (40 million
pounds) of suspended solids would be eliminated from treatment plant
loadings.

In the abatement of waste water flow and loss of solids from product
in canning and  freezing plants, a study was initiated in 1970 to
design a blanching process which would have a waste water flow of
only  107<> of  a commercial hot water blancher.  The project was sup-
ported by the University of Wisconsin and the USDA, and was conducted
by M. E. Lazar  and D. B. Lund at the Western Marketing and Nutrition
Research Division, USDA.  The project resulted in a new concept of
                                                               3 4
heating foods and the application to blanching was demonstrated * .
The process, individual quick blanch (IQB), required further evalua-
tion  and, therefore, the Western Laboratory conducted a study uti-
lizing IQB prior to freezing while the evaluation of IQB for blanch-
ing prior to canning was conducted in a Wisconsin canning plant.

The IQB process is a two-stage unit operation.  In the first stage,
the food piece is exposed to a heat source (condensing steam) for
such duration that the mass-average temperature is in the range re-
quired for blanching (generally greater than 85 C  [185 F]).  The
piece is then transferred to a second stage where the piece is held
adiabatically until the thermal gradients have equilibrated to the
mass  average temperature and the objectives of blanching have been
accomplished.  The process results in less waste generation because:
1) steam condensation is limited to that required for heating the

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product into the blanching temperature range, 2) there is minimal
opportunity for tissue damage and subsequent loss of cellular juices,
and 3) there is no overheating of some of the tissue as in deep bed
steam blanching which can result in tissue damage.

Lund  reported on the application of IQB to vegetables prior to
canning.  In that study, peas, corn, lima beans and green beans were
blanched, canned, stored and objectively and subjectively evaluated.
Evaluation of IQB, IQB with predrying and conventional pipe blanching
showed that up to a 99% reduction in waste water generation could be
achieved with IQB.  The study also revealed that although predrying
to greater than a 67» weight reduction would further reduce waste
water generation, product quality was adversely affected.

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                             SECTION IV
                             OBJECTIVES
The results in this report are a continuation and extension of the 1971
study.  The present study was undertaken for several reasons:  1) to con-
firm the 1971 results with IQB, 2} to compare the IQB process to deep-bed
steam blanching, 3) to apply the IQB process to different varieties of
peas, 4) to extend the IQB process to the blanching of root crops such as
potatoes, carrots and beets, and 5) to evaluate the heat-only stage of
the IQB process as a blanching method.  Objective 5) was included in the
study since it had been observed that after blanching, and prior to can
filling, vegetables are often held for one to two minutes during which
thermal equilibration could be accomplished.  If the vegetables could be
held in a relatively large mass to reduce thermal losses, blanching could
be accomplished.  The vegetables used in this study include peas (smooth
and wrinkled-skin varieties), corn, lima beans, green beans, potatoes,
carrots and beets.

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                             SECTION V
                       MATERIALS AND METHODS

PRODUCTS AND PROCESSING TIMETABLE
     Products chosen for this study were those grown and/or processed in
     large quantity in Wisconsin.  The 1971 study was done on Alsweet
     peas, Midway corn, Slim Green green beans and lima beans (variety
     unknown), and consequently, to verify the 1971 study, these products
     were used in this study.  Since there was concern regarding the
     response of the smooth-skin pea variety to the IQ8 process, Alaskan
     peas were also used.  Two wrinkled-skin varieties, Alsweet and Per-
     fection, were used.  In addition to these four vegetables, the root
     crops, potatoes, carrots and beets, were also processed.

     The effect of harvest date on the characteristics of blancher ef-
     fluent was assessed by making blanching runs throughout the process-
     ing season.   Experiments were conducted on three days for peas and
     corn, two days for lima beans and green beans and one day for pota-
     toes, carrots and beets.  Product forms and processing dates are
     given in Table 1.

     All products used in this study were obtained from either the Sun
     Prairie, Merrill, or Waunakee plants of the Oconomowoc Canning
     Company, Oconomowoc, Wisconsin.  Peas were taken from the produc-
     tion line immediately after inspection and just prior to blanching.
     They were transported to the pilot plant at the Department of Food
     Science, Babcock Hall, University of Wisconsin-Madison under water
                                  8

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to minimize product deterioration.  The blanching run was started
within two hours of leaving the canning plant.
       Table 1.  PRODUCT FORMS AND PROCESSING DATES
Processing
date
6/22/72
6/26/72
7/26/72
8/16/72
8/31/72
9/11/72
10/ 3/72
10/11/72
10/ 9/72
10/10/72
10/31/72
III 2/72
ll/ 7/72
Product
Peas
Peas
Peas
Corn
Corn
Corn
Lima bean
Lima bean
Green bean
Green bean
Potatoes
Beets
Carrots
Variety
A 1 sweet
Alaskan
Perfection
Midway
Midway
Midway
Thorogreen
Thorogreen
Slim green
Slim green
Superior
Ruby queen
Nantes
Form
4 sieve
3 sieve
3, 4, 5 sieve (mixed)
Whole kernel
Whole kernel
Whole kernel
3 sieve
3 sieve
3.8 cm.
3.8 cm.
0.64 cm. (1/4 in.) slice; medium
0.64 cm. (1/4 in.) slice; medium
0.64 cm. slice; medium
Corn was taken out of the processing line immediately before the
conventional blanching step.  The corn had been washed and screened,
It was also transported to the pilot plant under water.

Cut green beans were received from the Merrill, Wisconsin plant and
were transported from the plant to Madison by truck.  The green
beans were blanched and further processed immediately after receiv-
ing them.
Lima beans were taken from the processing line immediately after
inspection and were transported to the pilot plant under water.

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     Potatoes, carrots and beets were obtained from the Waunakee plant.
     All root crop products had been steamed and/or lye-treated, peeled,
     graded, and sliced.  Medium slice (3.2 - 4.4 cm. diameter) was used
     in the blanching studies.  Tests indicated that there was enzymic
     activity (peroxidase) even though the product had received a thermal
     treatment.  The product was brought to the laboratory and processed
     immediately.
BLANCHING METHODS AND EQUIPMENT
     Five blanching methods were investigated in this study and are shown
     in Table 2.  The first method was IQB (individual quick blanch).

                    Table 2.  BLANCHING METHODS
Method
IQB
IQB with
predrying
IQB heat
only
Deep bed
steam
Pipe
Peas
X
X

X

X

X
Corn
X
X

X

X

X
Lima
beans
X
X

X

X

X
Green
beans
X




X

X
Pota-
toes
X
X



X


Carrots
X




X


Beets
X
X



X


     The equipment was the same as that described in an earlier publica-
         3
     tion  and was on loan from the Western Regional Research Laboratory.
                          In essence the equipment consisted of two
     separate belt units, the first of which was approximately 91.4 cm.
     (3 ft.) by 21.6 cm. (8.5 in.) and the second of which was approxi-
     mately 122 cm. (4 ft.) by 20.3 cm. (8 in.).  The first unit was the
     heating section and had a feed hopper through which a single layer
     of product could be discharged onto the moving belt.  The residence
                                 10

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      time in this unit could be varied from 20  sec. to 2.5 rain.  The
      second unit, the hold unit, had adjustable belt speed and tunnel
      length.  Tunnel length was adjusted  by changing the  length of the
      cover on the unit.  In all experimental runs  reported here, the
      effective belt length was 30.5 cm. (1 ft.).   A diagram of the IQB
      unit is shown in Figure 1.

                    Figure 1.  IQB BLANCHING UNIT
(
       -MONOLAYER
I
)


- — x.— ^ C
v

LJCATIM/- ccn ir\M C
,V
*\s"**
—CUR

• Daae>««« d*n
« o a a A aJU0l
^ r
TAIN
J MULTIPLE
^-LAYER
V ~7^
                 Fast  Belt
              (Live Steam Heat)
     HOLDING     COOLING SECTION
     SECTION          (Optional)
     Slow Belt          (Chilled Air)
(Insulated, Adiabatic)
      The heat unit was heated by live  steam which was distributed by two
      pipe distributors, one below and  one  above  the belt.  The distributor
      below the belt directed the steam parallel  to the belt so product
      would not be blown off the belt,  and  the  distributor above the belt
      was directed toward the cover on  the  unit.  The hold section was
      heated indirectly by steam in two copper  coils, one on each wall
      of the unit.  The steam condensate and excess steam from this section
      was used to preheat the belt going into the hold section.  The hold
      section was separated from the heat unit  by a short transfer zone
      with a canvas curtain.  Some steam leakage  did occur from the heat
      unit into the hold unit.
                                   11

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The IQB unit was equipped with effluent drains on both the heat and
hold units.  Although the volume of effluent from each unit was
recorded separately, analysis and reporting of the data were done
on the total.

The second blanching method was IQB with predrying.  For predrying,
the vegetables were cycled through a 183 cm. (6 ft.) long by 30.5 cm.
(1 ft.) wide vibrating bed dryer.  Air at 71-82 C (160-180 F) (dry
bulb) was passed up through the vegetable bed, and the vegetables
were predried to approximately a 6% weight reduction.  A 6% weight
reduction was established based on results in the 1971 study.  It
was found that at higher weight reduction irreversible dehydration
occurred (i.e. the product would not rehydrate to initial wet weight)
and product quality was adversely affected  (most notably through
excessive skin rupture or excessive browning).

The third blanching method (IQB heat only) utilized only the heat
belt of the IQB unit.  Immediately after going through the heating
unit the product was discharged into plastic buckets.  Product was
held in the buckets until canning.

The fourth method was deep bed steam blanching.  The heat section of
the IQB unit was used for this method also.  The product was dis-
charged onto the belt in a 6.4-7.6 cm. (2.5-3 in.) deep layer.
Residence time in the unit was 2.5 min. for all deep bed blanching
trials.

The fifth blanching method evaluated was the commercial method—
pipe blanching.  The unit consisted of 122-152 m. (400-500 ft.) of
11.4 cm. (4.5 in.) diameter stainless steel pipe.  The length was
variable so that the residence time could be adjusted.  Product was
metered into the pipe at a preset rate so that the water to product
ratio was constant.  After blanching, the product was dewatered at
                            12

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a dewatering reel and was further processed.  The blanch water was
then screened, make-up water was added and the water recycled into
the pipe.  Water and vegetables in the pipe blancher  were heated
by direct steam injection.

Blanching times used in  the IQB heat/hold sections were determined
by making simple observations on the  pipe blanching operation.  For
peas,  it was observed that conventional  pipe blanching operation
resulted in peroxidase inactivation and, therefore, peroxidase in-
activation was the  criterion for establishing heat/hold times in
IQB.   Appropriate heat/hold times were determined by the procedure
described in Lund et_ al^. .     For corn  and lima beans, water tempera-
ture  in pipe blanching was approximately 77 C  (170 F) and, conse-
quently, heat/hold  times were chosen  that would result in a final
corn  or lima bean temperature of 77 C.   Green beans were also pipe
blanched at 77 C but the conventional IQB process could not be used.
With  green beans, the function of blanching is to activate the enzyme
pectin methyl esterase which prevents sloughing of the green bean
following canning.  Since the enzyme  is  inactivated at temperatures
above  82 C (180 F), the  IQB heat section could not be heated with
100 C  (212 F) steam.  Therefore, a steam-air mixture at 79 C (175 F)
was used in the IQB heating section.  Heat/hold times were chosen
that would result in an  equilibrated  temperature of 77 C.  For pota-
toes,  carrots and beets,  a direct comparison to pipe blanching could
not be made since these  products are not usually blanched prior to
canning.  The only heat  treatment these products receive prior to
retorting is  in the peeling operation.  These products were included
in the IQB and deep-bed  experiments, however, since they are blanched
prior  to freezing and some processors have experienced undesirable
color changes (particularly with beets and potatoes) which can be
avoided by blanching after slicing or dicing.  Blanching conditions
were chosen such that peroxidase was  inactivated.  For deep-bed
blanching,  all vegetables were blanched  for 2.5 minutes, the maximum
                             13

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    residence time of the IQB heat section.  Blanching conditions for
    all vegetables are shown in Table 3.

           Table 3.  BLANCHING TIMES AND TEMPERATURES3
Commodity
Peas

Corn

Lima beans

Green beans

Potatoes

Carrots

Beets

IQB
30 sec/100 C heat
45 sec hold
20 sec/100 C heat
30 sec hold
20 sec/100 C heat
80 sec hold
20 sec/82 C heat
80 sec hold
60 sec/100 C heat
60 sec hold
45 sec/100 C heat
60 sec hold
45 sec/100 C heat
60 sec hold
Heat only
30 sec/100 C

20 sec/100 C

20 sec/100 C









Deep bed
2.5 min/100 C

2.5 min/100 C

2.5 min/100 C

2.5 min/82 C

2.5 min/100 C

2.5 min/100 C

2.5 min/100 C

Pipe
4 min/93 C

1.5 min/77C

4 min/77 C

2 min/77 C







All time/temperature combinations resulted in negative peroxidase except
for green beans.  Time/Temperature (C).
    For each experimental run, three 9.09 kg. (20 Ib.) batches of the
    vegetable were treated by one of the four steam blanching methods.
    Initial weight, weight after drying (if the product was predried),
    and weight after blanching were recorded.  For each 9.09 kg. run, all
    waste water generated by processing the vegetable in the blancher was
    measured.  A composite sample of the waste water was subjected to
    analysis for the following:  1) BOD5> 2) COD, 3) total solids, 4)
    suspended solids, 5) soluble phosphorus, 6) total phosphorus, 7)
    total organic nitrogen, 8) NHj-Nitrogen, 9) NO^Nitrogen, 10) N02~
    Nitrogen, 11) volatile solids, 12) suspended volatile solids, and
                                 14

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13) pH.  Part of the analyses were performed by the Wisconsin Depart-
ment of Natural Res
analyses were used
ment of Natural Resources.  In all cases  the standard methods for
                  ,6
In order to report waste water generation on the basis of amount of
product processed, a blank was determined for each run by operating
the equipment with the  steam  on and  the belts moving  for a period
of time equal to  the time to  process  the 9.09 kg. lot.  Equipment
effluent  (due to  heat  losses  from the equipment, heating the belt and
any water  carried in the steam line)  was measured and this value sub-
tracted  from the  volume generated during the actual run.  All analysis
values were corrected  by the  resulting dilution factor.  Immediately
following blanching, samples  were filled into 303 x 406 cans to the
appropriate fill  weight, brine added, cans  sealed and retorted in a
Steritort  following  the heat/cool process used in the canning plant.

For  the  pipe blancher,  effluent was  collected at the  dewatering reel
and  subjected to  the same analyses as other samples.  Water usage was
monitored  by a  water meter in the water make-up line  and was recorded
daily.  By knowing the  daily  case pack on the line, the liters of
water per  case  of product could be calculated.  Since the pipe
blanching  water was heated by direct  steam injection, the effluent
generated  by the  system was larger than that calculated from the
water make-up readings.  To adjust for the steam condensation in
heating the product up, it was assumed that 4.23 kg.  (9.3 Ib.) of
steam would condense for every 45.5 kg. (100 Ib.) of  product being
heated 38.0 C (100 F).  This resulted  in 91.7 liters  of steam con-
densation  per kkg. of product (22 gal/ton).  This value has been
added to all pipe blancher values as  calculated from  water meter
readings.  Waste  generation reported  for the pipe blanching system
will still be low since this does not account for heat losses from
the piping system.  However,  for  the  system we monitored heat losses
would probably  not contribute more than 8.3-20.9 l./kkg. (2-5 gal/ton)
of product processed.
                              15

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     To insure that representative samples of waste water were being
     collected from the pipe blancher, on some occasions (at least two
     days for each vegetable), water samples were collected at two-hour
     intervals.  Results indicated that within two hours of start-up the
     blancher water was in steady state.  Therefore, all samples were
     taken at least two hours after start-up.  For later evaluation and
     comparison, several cases of canned vegetables processed at the same
     time the experimental samples were processed were brought to the
     laboratory.
PRODUCT EVALUATION
     After blanching, the product was hand packed into 303 x 406 cans,
     boiling water and the appropriate volume of concentrated brine were
     added and the cans were sealed.  The cans were then thermally proc-
     essed in a Steritort using rotation speed and heat/cool times iden-
     tical to those used in the canning plant.  Product was then stored
     at 32 C (90 F) along with conventionally processed product which had
     been obtained from the canning plant.  Product evaluations were con-
     ducted at 1, 3, 6 and 9 months'  storage.  The tests performed on
     each product are shown in Table 4.  Standard procedures were followed
     for all tests.  The method of Van Buren et al.  was used for the
     slough test on green beans.   At each evaluation a five-can subsample
     for each experimental process and conventional process was analyzed.

     Product quality was assessed by triangle taste test comparing each
     experimentally processed product to the corresponding control process
     product (canned product obtained from the canning plant).   Taste
     testing was conducted in the Sensory Evaluation Laboratory of the
     Department of Food Science using personnel who were trained in
     sensory evaluation.  Differences could be assessed on the basis of
     color, texture or flavor and preference was noted.  To streamline
     the presentation of sensory evaluation data, two pieces of informa-
     tion were generated.  The first consists of three numbers  separated
                                  16

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            Table 4.  PRODUCT EVALUATION TESTS
Test
Taste panel
Can vacuum
Drained weight
Brine sediment
Slough
Percent splits
Peas
X
X
X
X

X
Corn
X
X
X



Lima
beans
X
X
X



Green
beans
X
X
X

X
X
Pota-
toes
X
X
X



Carrots
X
X
X



Beets
X
X
X



by slashes such as 10/5/5.  The first number  (10) is the number of
correct judgments which preferred the experimentally blanched canned
product; the second number  (5) is the number of correct judgments
which preferred the control sample; and the last number (5) is the
number of correct judgments which showed no preference.  The second
piece of information was the level of distinction between samples.
There was either no significant difference (NS) or differences
were identifiable at the 0.1%, 1% or 5% level.
                              17

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                             SECTION VI

                       RESULTS AND DISCUSSION
FLOW VARIABILITY OF BLANCHING WASTES
     During the processing season daily water meter readings were recorded
     for water usage in the pipe blancher for peas, corn, and green beans.
     Examination of the data showed that the most consistent characteristic
     was the extreme variability in water used per case or ton of vegetable.
     The data were so scattered that it is tenuous at best to draw con-
     clusions.  However, in the hope of comparing IQB to pipe blanching,
     average water usage rates were calculated.  An example of variability
     of data is the range of data reported for green bean blanching.  On
     8/24/72 there was a reported 24.2 l./case (6.4 gal/case) water usage
     in the pipe blancher; whereas on 9/16/72 only 0.45 l./case (0.12 gal/
     case)  was recorded.  This is over a 50-fold difference!  In pea
     blanching, on 6/27/72, 6.6  l./case (1.75 gal/case) was recorded for
     the pipe blancher compared to 0.33 l./case (0.088 gal/case) on
     7/19/72, a 20-fold difference.  This tremendous variability con-
     tributes to many misinterpretations regarding water usage in blanch-
     ing operations.  One factor responsible for variability is incomplete
     knowledge of the blanching system.  In our case we were not informed
     that the blancher could be filled from two separate sources, one at
     the inlet end and one at the discharge end.  Consequently, we only
     monitored water inlet from one source.  Once this was recognized we
     were able to screen the data to assure -that a representative value
     was reported.  A second factor responsible for variability of flow is
     the lack of control on the blanching unit operation.  Many times the
                                  18

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blancher is not equipped with a flow regulating device but rather
there is just a water line bringing water into the  system.  The
foreman or worker merely opens a water valve  to the blancher and has
no guidance as to the appropriate  flow rate to use.  Therefore, on
some occasions flow  is very high,  while on others it is very low.

In addition to the variability of  flow between days, there is also
variability of flow  within a day.  An example of water flow from
blanching during one day of processing for peas, corn, green beans
and  lima beans is shown in Table 5.  The percent total solids of the
blancher effluent is also given.   It can be seen that there is con-
siderable variability  in the water usage pattern throughout the
processing day.   This variability reflects the cyclic nature of the
blanching operation  in that the blancher is generally drained and
refilled several times during the  operating day.  This cleanup is
necessitated by the  fact that the  solids leached from the tissue
during blanching undergo oxidative and thermal degradation to very
flavorful compounds.  These compounds can produce off-flavor in the
final product unless they are removed periodically.   For peas the
blancher was refilled every 6-8 hours,  for corn every 12 hours, and
for  lima beans every six hours.   For green beans the blancher was
refilled every six hours but no make-up water was added between re-
fills.  Under these conditions the total solids in the blanch water
varies considerably, for example,  from 0.55% TS   to 1.35% TS.  With
the other vegetables the % TS   is kept relatively constant by the
addition of make-up water.

The data reported  in Table 5 for lima beans are from the 1971 study.
No data are available on water usage for lima beans for 1972 due to
a change in blanching conditions.   In 1971, the water make-up rate
was approximately 76 l./case (20 gal/case), about ten times higher
than that reported for the other vegetables.  At the end of the 1971

                             19

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Table 5.  HOURLY MAKE-UP FLOW RATES AND TOTAL SOLIDS CONTENT OF PIPE
          BLANCHER WATER FOR PEAS,  CORN, LIMA BEANS AND GREEN BEANS
Time
(hrs)
2
2.5
3
3.5
4
6
8
10
12
14
16
18
1
Peas
% TS l./hr
2.31 719
2.15 590
2.24 795
2.90 636
2.90 689
2.70 708






Corn
% TS
2.47
2.58
2.50
2.30
2.05
1.09
2.24
3.00
2.79
2.12
2.26
1.95
l./hr
1703
1363
1363
1363
1817
1249
1400
1400
4126
265
2725
1779
Lima
beans
% TS l./hr
0.59 24600



0.39 20250
0.62 30470
0.43 15030
0.37 20530




Green
beans
% TS 1
0.71



1.12
0.63
1.01
0.97
0.55
1.23
1.35

./hr
8880



0
6230
0
0
9750
0
0

     processing season this observation was made to the plant personnel
     who immediately sought to correct the situation for 1972.  The high
     water usage rate was the result of the foaming problem associated with
     lima bean blanch water.  In 1972, several corrective actions  were
     taken:  1) use of an antifoam agent in the blanch water, 2) use of
     hard water instead of soft and 3) maintenance of a full reservoir
     prior to the pump (eliminated air entrapment).  Since the water
     make-up line was hard water and fed several pieces of equipment si-
     multaneously, it was impossible to monitor water addition rates.  How-
     ever, after conversations with plant personnel, it was estimated that
     water usage rates for lima beans were about the same as those for
     corn.
                                  20

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CONDENSATION OF RAW DATA
     In this type of study volumes of raw data can be obtained and much
     of it can, in turn, be multiplied considerably by calculations.  In
     order to simplify the examination of data and to reach the really
     pertinent information obtained in this study, the raw data were con-
     densed and only the pertinent calculations were performed.  Many
     more calculations can be done but they do not serve to demonstrate
     more effectively the results contained herein.

     The raw data for each of the blanching runs are given in the Appendix
     in Tables Al - A14.  The first table for each product presents the
     physical characteristics of the run such as belt loadings, effluent
     generated (expressed as l./case), product yield and solids lost as
     product.  "Belt loading" results will be discussed in a later sec-
     tion.  "Effluent generated" was calculated from the volume of waste
     collected per unit of raw product.   "Product yield" is the ratio of
     blanched weight to initial weight times one hundred.  "Solids lost
     as product" represents the solids in the blanch water expressed on
     the basis of product equivalents.   For  this calculation it was
     assumed that peas  were 20% total  solids,  corn was  25%, lima beans
     were 32.5%,  green  beans  were 10%, potatoes  were 20.2%, carrots were
     11.8% and  beets  were 12.7%.   These  values are from USDA Handbook
     No.  8.

     The  second table presenting  raw data on each blanching run for each
     product characterizes  the  effluent.   All  of the data are expressed
     as ppm or  %   and  represent  the concentration of the particular com-
     ponent in  the effluent»  A more convenient  way of  expressing these
     data  for discussion  purposes is to  express  the water characteristics
     on the basis of  kkg. of  processed product.   This was done and selected
     characteristics  will be  presented in later  discussions.
                                  21

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The notation used in the tables to describe the blanching treatment
is relatively straightforward.  IQB stands for individual quick
blanch, the "-0" or "-number" represents the predrying treatment (0
means no predrying; number expresses the % weight reduction in pre-
drying), the "-sec" represents the heat only process of IQB and deep
bed represents deep bed steam blanching.  Pipe refers to pipe blanch-
ing, the control.

Examination of the raw data shows that several variables had no
effect on blanching characteristics of the product.  For peas there
did not appear to be an effect due to variety or harvest date on
blanching characteristics.  Therefore, the data within one blanching
treatment could be averaged to simplify presentation.  Similarly with
corn, there did not appear to be an effect of harvest date.  There-
fore, the data were averaged within each blanching treatment.  Lima
beans, green beans, potatoes, beets and carrots also showed no har-
vest date effect.  Therefore, averages are used in discussing the
results.  It should be pointed out that the variable harvest date
is not the same as the variable maturity.  For example, although
corn may be harvested on different dates it may be of the same ma-
turity and consequently there can still be a maturity effect.  With
corn in particular, it might be suspected that there would be a dif-
ference in blancher effluent for mature versus immature corn.

Although several parameters were measured on the blancher effluent
only a few will be discussed.  Probably the most important parameters
are BOD^, total organic nitrogen and total phosphorus  since the
relative concentrations of these three components are used to assess
the response of the waste to biological waste treatment.  Consequently
in discussing the data, only these three parameters will be discussed.
                             22

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PEA BLANCHING
     A summary of the pea blanching data is given in Table 6.

              Table 6.  SUMMARY OF PEA BLANCHING DATA3
Blanching
treatment
IQB-6.9
IQB-0
30 Sec
Deep bed
Pipe
Effluent
generation
(l./kkg)
146
225
209
313
384
BOD5
(kg/kkg)
1.8
2.6
2.5
4.3
3.0
Total
organic
nitrogen
(kg/kkg)
0.09
0.13
0.13
0.22
0.17
Total
phosphorus
(kg/kkg)
0.02
0.04
0.03
0.05
0.05
Product
yield
(%)
88.8
89.3
90.4
83.3
--
Solids
lost as
product
a)
1.53
2.07
2.09
3.11
--
  Expressed  per  kkg  of blanched product.  See Tables Al and A2 for
  complete data.
  IQB-6.9 means  IQB  with a 6.9% weight reduction prior to blanching.
  IQB-0 means  IQB without predrying.
  30  Sec means heat  section only of IQB.
  Deep bed means deep bed steam blanching.
  Pipe means pipe blanching.

     The first  important observation is that all of the steam blanching
     methods resulted in less effluent generation than pipe blanching.
     Predrying by an average of 6.97, weight reduction reduced waste genera-
     tion by 62% while deep bed blanching reduced the waste stream by 18%.
     As expected, predrying showed less generation of waste than IQB or
     30 sec. heat treatments.  Predrying the surface of the pea allowed
     the condensed steam to rehydrate the surface rather than running off.
     The IQB-0 and 30 sec.  heat treatments resulted in nearly the same
     total effluent generation indicating that most of the effluent is
     generated in the heat section of IQB from steam condensation.

     The value of 225 l./kkg (54 gal/ton) reported here for IQB-0 agrees
     quite well with the 200 l./kkg (48 gal/ton) for steam blanching peas
                                  23

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                           g
as reported by Rails et al.  and with the theoretical value obtained
when a mass balance is performed on the unit operation.  In Rails
et al. study the loading rate was only 2 kg/nr (0.4 pound/ft ) of
belt suggesting that they had the equivalent of an IQB heat stage.
The residence time, however, was much longer than the 30 sec. used
in IQB.

The deep bed steam blanching treatment resulted in 313 l./kkg (75
gal/ton product), nearly 50% more than IQB blanching.  The greater
effluent generation is due to two factors:  1) overheating of some
of the tissue resulting in greater juice loss and 2) a lower surface
water holding capacity of the heated bed of peas.  The first factor
is evident from the higher BOD^, nitrogen and phosphorous values
reported for the deep bed treatment.  Also, the solids lost as
product is nearly 50% more than for IQB.  The second factor, lower
water holding capacity of the bed of peas, is a result of the higher
mass average temperature of the peas in the deep bed treatment.
With the residence time of 2.5 minutes the bed temperature was much
higher and consequently the viscosity of the water and the surface
tension of water were lower resulting in more water running off.

The 384 l./kkg (92 gal/ton) reported here is much lower than other
values reported for water blanching systems.  Weckel et al.  reported
a waste water generation of 1420 l./kkg (340 gal/ton) for a pipe
blanching while Rails et al.8 reported 4170 l./kkg (1000 gal/ton)
for a draper-type water blancher.  The value reported here reflects
a very important concept recognized by the canning plant personnel.
They have cut back the water make-up on a regular basis while con-
tinuously checking product quality.  This has allowed them to cut
water usage drastically through control on the process.  The high
value reported by Rails et al.& may not necessarily reflect excessive
waste generation with the draper-type blancher.  Rather it may re-
flect the batch-type nature of the way in which the experiment was
                             24

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conducted.   Perhaps more  peas  could have  been  processed  in  the
blancher before  the water had  to  be changed.   Also,  a feed  and  bleed
system would reduce water usage.

The BOD- reported  here for steam  and  pipe blanching  corresponds quite
       •*                         Q
well  to  the data of Rails et al.  .  They  reported a  COD  of  8.3  kg/kkg
 (16.6 Ib/ton) for steam blanching and if  we assume a BOD/COD ratio  of
0.60  this  would  result in a BODg  of about 5 kg/kkg (10 Ib/ton).  The
BOD/nitrogen/phosphorous ratio was surprisingly constant with an
average  of 82/4.4/1  (range 55-117/3.1-7.6/1.This indicates  that this
waste has  an adequate carbon to nitrogen  to phosphorous  ratio for biological
 treatment.

 Finally, the product  yield is  given in Table 6.   Product yield  was
 quite constant between the IQB treatments but  deep bed steam blanch-
 ing resulted in considerably greater  loss of yield.   For deep bed
 steam blanching  this  lower yield  is due to tissue breakdown and
 lower water holding capacity of the peas,  as explained earlier.
 For IQB  blanching  most of the  weight  loss  is also a  result  of the
 lower moisture holding capacity of the  surface.   From experiments
done  in  1971,  a  cold pea  can hold up  to 15% by weight as  surface
moisture.  After blanching,  the surface is  nearly dry even  though
steam has condensed on the surface.   The hot surface can hold only
up to 6% by weight as water and thus  loss  of surface moisture would
account for up to  9% weight  loss.

The product yield value would  appear  to be  too  low for economic con-
sideration of IQB; however,  the process should be evaluated primarily
on the basis of  solids  lost  since this value represents  true product
loss.   Product yield reflects  the loss  of  surface water  as  well as
product loss.  It would be anticipated  that hot water blanching
                                                            9
would result in  even greater solids loss  as reported by  Lee .
                             25

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The results of objective evaluation of peas is shown in Table 7.
It is noticed that all cf the can vacuum values for the experimentally
blanched samples are higher than that for pipe blanched samples.  This
is due to the fact that the fill water temperature was higher in the
experimentally blanched samples.  In the laboratory the fill water
temperature was near 96 C (205 F) whereas in the canning plant it
was 82-88 C (180-190 F).  This difference could account for the
difference in can vacuum.  This demonstrated, however, that peas
could be successfully steam blanched prior to canning and that there
was adequate air removal from the tissue.  The can vacuum decreased
slightly upon storage, as expected.

The drained weights of all steam blanched samples were higher than
those of the control. This was not likely the result of the blanching
treatment but rather was the result of a slight overfill.  The fill
weight was 292.5 g. (10.3 ounces) and the resulting drained weight
averaged 320.9 g. (11.3 ounces), a 28 g. (one ounce) weight gain
upon retorting and cooling.

Brine sediment values reflect a problem associated with predrying
prior to IQB.  The brine sediment values were consistently higher
for the predried samples.  This is due to skin splitting that occurs
during predrying and subsequently comes off in the agitated retort
operation.  Compared to pipe blanching, the other steam blanching
systems are quite acceptable.

Finally, the percent split data are presented.  Although the percent
split is higher for the steam blanched samples, this apparently was
not detrimental to product quality.  The brine sediment value did
not seem to reflect the split damage.  Greater percent splits in
steam blanching compared to water blanching may reflect the dif-
ference in heating rates.  With steam blanching the temperature
increases very rapidly resulting in a rapid expulsion of tissue
                             26

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          Table  7.  SUMMARY OF OBJECTIVE EVALUATION OF PEAS
Blanch-
ing
treat-
ment

IQB-6.9
IQB
30 Sec
Deep
bed
Pipe

IQB-6.9
IQB
30 Sec
Deep
bed
Pipe

IQB-6.9
IQB
30 Sec
Deep
bed
Pipe
Can Vacuum
(cm. Hg. vacuum)
Months of storage
1 3 6 9
Avg.
34.8
34.0
29.7
31.5
21.6

320.4
316.4
315.8
J37.4
295.1
Range
26.4-39.9
27.2-37.3
21.6-36.6
23.4-36.8
17.0-30.0

312.1-324.3
311.0-323.2
308.4-320.1
326.6-343.6
285.7-305.6
Avg.
31.5
32.3
29.5
30.7
21.6

326.8
319.2
313.5
337.4
301.0
Range
20.6-38.4
20.8-41.1
18.3-36.8
23.4-34.5
13.7-28.4
Avg.
31.8
32.0
28.4
28.4
20.8
Range
22.1-36.8
22.4-38.4
21.6-31.8
19.8-33.3
16.0-26.9
Drained Weight
(g.)
315.8-337.1
311.3-326.9
307.6-317.5
329.4-345.3
291.1-307.0
322.6
318.6
312.7
332.3
301.6
315.8-328.0
314.4-320.9
309.0-315.5
325.7-337.7
293.4-305.6
Avg.
32.0
30.2
29.7
29.5
17.5

320.4
320.1
315.0
334.3
302.5
Range
27.9-36.1
24.4-36.8
25.4-31.8
26.4-31.5
10.2-24.9

313.0-324.6
311.5-328.0
309.8-318.4
326.6-341.9
299.1-305.9
Brine Sediment
m
6.29
3.82
4.09
3.96
5.30
5.05-8.18
3.69-3.91
2.97-5.06
2.45-6.12
3.23-8.76
7.23
4.23
3.73
3.83
3.59
5.05-10.36
3.88-4.56
2.81-5.23
3.45-4.37
2.36-5.27
5.41
3.81
3.41
4.07
4.05
5.24-5.57
3.44-4.17
2.98-3.81
3.28-5.06
2.15-7.00
4.59
3.38
4.80
3.13
3.89
4.46-4.72
3.33-3.43
1.79-8.30
2.88-3.39
2.16-6.08
Each average consists of at least nine observations.
                                   27

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  Table  7  (continued).  SUMMARY OF OBJECTIVE EVALUATION OF PEAS'
Blanch-
ing
treat-
ment
IQB-6.9
IQB
30 Sec
Deep bed
Pipe
Splits in Peas
(%)
1
Avg.
38
28
36
40
18
Months of Storage
3 6
Range
30-48
26-30
29-40
32-56
14-29
Avg.
35
41
36
33
22
Range
29-39
39-43
29-43
28-39
13-29
Avg.
35
30
27
28
21
9
Range
26-45
24-34
21-37
19-37
14-27
Avg.
30
24
30
29
20

Range
26-35
19-30
20-40
23-34
16-25
 Each average consists of at least nine observations.
     gases.  This sudden expansion of gases may  fracture  in the peas
     resulting in eventual splitting.  With water blanching, on the other
     hand, the temperature rise is slow enough to allow tissue gases to
     diffuse out of the tissue without developing excessive pressures.

     A summary of the subjective evaluation of peas is given in Table 8.
     From these data it is concluded that steam blanching resulted in a
     canned pea product at least as good as that produced with pipe blanch-
     ing.  In those cases where there was a significant difference, the
     steam blanched product was generally preferred.

     In conclusion, the study with peas indicates that IQB can be success-
     fully used for pea blanching with a 40% decrease in liquid waste generation
     compared to pipe blanching.  Compared to deep, bed steam blanching,
     IQB produced 28% less effluent and less product loss.  IQB with pre-
     drying is not recommended due to significant increases in brine
     sediment.  Product quality as evaluated by objective and taste panel
     tests was at least as good for IQB as for pipe blanching.
CORN BLANCHING
     A summary of the corn blanching data is given in Table 9.
                                  28

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         Table 8.  SUMMARY OF SUBJECTIVE EVALUATION OF PEAS
Blanching
treatmenta
IQB-6.25-4-A1S
IQB-O-4-Als
30 Sec-4-Als
Deep bed-4-Als
IQB-7.0-3-Ala
IQB-O-3-Ala
30 Sec-3-Ala
Deep bed-3-Ala
IQB-7.5-Perf.
IQB-0-Perf.
30 Sec-Perf.
Deep bed-Perf.
Storage time (months)5
1369
0.1%
8-4-4
5%
8-3-2
NS
0.1%
13-4-3
5%
5-6-2
NS
1%
4-5-5
NS
NS
NS
NS
NS
1%
8-5-3
1%
9-4-2
0.1%
12-3-2
NS
NS
NS
NS
NS
„
_.
NS
NS
0.1%
11-2-3
1%
6-3-6
0.1%
9-2-3
0.1%
7-6-1
0.1%
5-7-7
NS
NS
1%
2-6-9
1%
4-6-7
NS

_ —
0.1%
7-5-8
0.1%
7-6-7
0.1%
12-5-3
0.1%
12-3-4
5%
3-7-6
NS
5%
5-5-4
NS
NS
NS
NS
NS
 IQB-6.25 means IQB with a 6.25% weight  reduction prior  to blanching.
 IQB-0 means IQB without predrying.
 30 Sec means heat only stage  of IQB.
 Deep bed means deep bed steam blanching.
 4 or 3 refers to sieve size;  Perfection was  sieve size  3, 4  and  5.
 Als means Alsweet;  Ala means  Alaskan; Perf.  means Perfection.
3Each sample was compared to a pipe-blanched, canned  control.   The control
 was canned the same day as the experimental  sample.   The top number  is
 the level of significance and the bottom  three  numbers  represent number
 of judges preferring experimental sample,  control and no preference,
 respectively.   NS means no significant  difference.
                                  29

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              Table 9.  SUMMARY OF CORN BLANCHING DATA


Blanching
treatment
IQB-7.5
IQB-0
20 Sec
Deep bed
Pipe

Effluent
generation
Q./kkg)
86
125
125
163
730


BOD5
Ckg/kkg)
1.4
2.7
3.0
4.4
4.9
Total
organic
nitrogen
(kg/kkg)
0.017
0.039
0.037
0.049
0.089

Total
phosphorus
(kg/kkg)
0.008
0.020
0.019
0.028
0.034

Product
yield
(%)
93.1
97.1
97.4
94.2
--
Solids
lost as
product
a)
0.81
1.61
1.52
2.42
--
«
 Expressed per kkg of blanched corn.  See Tables A3 and A4 for complete
 data.
bIQB-7.5 means IQB with a 7.5% weight reduction prior to blanching.
 IQB-0 means IQB without predrying.
 20 Sec means heat section only of IQB.
 Deep bed means deep bed steam blanching.
 Pipe means pipe blanching.
     As with pea blanching, all of the steam blanching methods produced
     less effluent than pipe blanching.  IQB without predrying reduced
     effluent generation by 33% compared to pipe blanching while a 7.5%
     weight reduction prior to IQB reduced effluent generation by 88%.
     The effluent generated per ton of corn is considerably less than that
     for peas because of the difference in the nature of the surface of
     the two vegetables.  Cut corn surfaces expose starch which upon heat-
     ing can absorb water resulting in less water loss.  On the other
     hand, the 8005 for corn was about the same as that for peas indi-
     cating that water that did drain off corn carried with it more
     solids.  In pipe blanching, water usage for corn was nearly double
     that for peas.  This reflects the fact that with corn, the blanching
     process is primarily a wash step to remove reducing sugars and other
     components that may contribute to brown color development during
     thermal processing.  In some plants, corn is not blanched prior to
     canning.  Weckel et al.  reported an average of 1043 l./kkg
                                  30

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 (250 gal/ton) for pipe blanching corn.  As with' peas, deep bed steam
blanching resulted in greater effluent generation than IQB but it
was still considerably less than pipe blanching.

The BOD/N/P ratio for corn averaged 151/2.1/1 (range 88-237/1.5-2.9/1)
 indicating that the waste may be low in nitrogen for biological
 treatment.  From Table A4 the BOD/COD ratio was 0.78.  Soderquist
et al.   reported a BOD/COD ratio of 0.75 for corn wastes.  That
figure, however, included waste generated at unit operations in ad-
dition to blanching.

With respect to product yield there are some interesting observa-
tions.  First, with predrying the product yield is lower than with
IQB without predrying.  This reflects the fact that the corn surface,
once dehydrated, is very difficult to rehydrate and thus this yield
reflects losses of product solids and loss of reabsorbing capacity
of the surface.  Deep bed steam blanching resulted in greater product
 loss primarily through solids lost in the effluent.

Table 10 presents the results of the objective evaluation on steam
blanched and pipe blanched corn.  As with peas, can vacuum for the
steam blanched samples is higher than that for the pipe blanched
sample.  This reflects the lower water fill temperature used in the
canning plant compared to the laboratory pilot plant.  There was no
significant difference in drained weight between any of the samples.

A summary of the subjective evaluation of corn is given in Table 11.
There appears to be a significant difference between steam blanched
and pipe blanched samples but the preference is not consistent.  It
was observed that the steam blanched samples were darker in color
than the pipe blanched samples attesting to the fact that the blanch
step is primarily a wash step for corn.  This darker color, however,
did not manifest itself in consumer preference meaning that perhaps

                             31

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     blanching does not have to serve as a wash step if the consumer cannot
     detect the color difference.

         Table 10.  SUMMARY OF OBJECTIVE EVALUATION OF CORN3
Blanch-
ing
treat-
ment

IQB-7.5
IQB
20 Sec
Deep bed
Control-
IQB-7.5
IQB
20 Sec
Deep bed
Control
Can Vacuum
(cm. Hg. vacuum)
Months of Storage
1 3 6 9
Avg.
26.9
31.8
28.2
26.4
23.6
327.7
324.6
325.5
331.7
327.2
Range
21.6-30.7
29.0-35.1
23.6-36.6
22.6-31.8
18.5-28.7
326.9-294.1
322.6-327.7
320.9-330.9
330.3-332.8
310.4-343.1
Avg.
27.9
32.5
32.3
31.0
18.5
Di
328. Ob
317.8
317.2
326.9
304.4
Avg.
21.8
26.7
23.6
20.6
17.5
rained V
(g)
326.9
318.4
315.8
327.7
324.6
Range
15.2-27.4
20.8-34.8
19.1-31.8
14.5-31.2
16.5-19.6
/eight
321.8-330.3
315.8-320.1
314.7-317.2
322.6-330.3
315.8-339.4
Avg.
23.1
27.7
27.7
24.6
22.6
322.9
323.5
321.2
330.3
322.1
Range
21.6-25.4
25.4-32.0
22.6-34.3
51.8-31.8
17.8-26.2
317.8-329.4
316.1-328.3
320.6-322.1
328.3-332.3
313.5-337.1
o
, Each average consists of at least nine observations.
 Only one series of samples was evaluated after three months' storage.

     In conclusion, IQB and deep bed steam blanching both result in
     drastic reductions of effluent generation in corn blanching.  How-
     ever, in both cases a darker product resulted after retorting.  To
     maintain a bright golden yellow color, corn would have to be thor-
     oughly washed prior to steam blanching.  This wash step, in turn,
     defeats the purpose of steam blanching since the wash step would
     create another high volume-low load effluent steam.  Therefore, the
                                  32

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       Table 11.  SUMMARY OF SUBJECTIVE EVALUATION OF CORN
Blanching
treatmenta
IQB-7.5
IQB-0
20 Sec
Deep bed
IQB-7.5
IQB-0
20 Sec
Deep bed
IQB-7.5
IQB-0
20 Sec
Deep Bed
Storage time (months )b
136 9
1%
4-10-4
5%
3-8-5
NS
5%
3-8-3
0.17.
8-13-1
NS
NS
NS
1%
8-5-4
17,
10-8-0
0.17.
18-3-1
0.17.
17-2-0
17.
4-7-3
0.17.
0-11-3
17.
9-4-1
0.17.
6-9-1
_.
„
m* •
„
..
— —
_.
--
0.17.
2-17-4
NS
NS
NS
0.1%
2-12-7
NS
0.17.
3-7-2
17.
7-9-2
0.17.
10-6-5
1%
9-7-2
NS
0.17.
11-7-2
NS
57.
3-4-6
1%
2-9-4
NS
17.
6-6-5
17.
7-3-6
0.17.
10-6-2
NS
0.17.
18-3-4
0.17.
5-16-4
0.17.
16-3-3
0.1%
11-5-3
IQB-7.5 means IQB with 7.57. weight reduction prior to blanching.
IQB-0 means IQB without predrying.
20 Sec means heat only stage of IQB.
Deep bed means deep bed steam blanching.

Each sample was compared to a pipe-blanched, canned control.
The control was canned the same day as the experimental sample.   The
top number is the level of significance and the bottom three  numbers
represent number of judges preferring experimental sample, control
and no preference, respectively.  NS means no significant difference.
    advantage of producing a bright yellow corn must be weighed against
    the disadvantage of creating an effluent stream and the cost of its
    subsequent treatment.  Since blanching of corn must be done when
    corn is packed into No. 10 cans, there is still a use for steam
    blanching.
                                 33

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LIMA BEANS
     Lima bean blanching results are summarized in Table 12.

           Table 12.  SUMMARY OF LIMA BEAN BLANCHING DATA3
Blanching
treatment**
IQB-5.0
IQB-0
20 Sec
Deep bed
Pipe
Effluent
generation
U./kkO
67
171
133
238
821
BODs
fke/kkg)
0.35
1.7
2.4
3.5
0.65
Total
organic
nitrogen
(kg/kkR)
0.02
0.12
0.06
0.17
0.02
Total
phosphorus
(kg/kkg)
0.004
0.02
0.015
0.04
0.01
Product
yield
(%)
97.5
93.4
96.7
88.7
--
Solids
lost as
product
a)
0.24
0.86
0.54
1.38
--
 Expressed per kkg of blanched product.  See Tables A5 and A6 for
 complete data.
3IQB-5.0 means IQB with a 5.0% weight reduction prior to blanching.
 IQB-0 means IQB without predrying.
 20 Sec means heat section only of IQB.
 Deep bed means deep bed steam blanching.
 Pipe means pipe blanching.
     Results with lima beans parallel those obtained with peas and corn.
     The effluent generation values are similar to those reported for
     corn in Table 9 and reflects the water holding capacity of the sur-
     face of the lima bean.  In lima bean processing the blanch step
     serves to partially rehydrate the dry lima bean seeds.

     The pipe blanching method produced 821 l./kg (197 gal/ton) compared
     to only 171 l./kg (41 gal/ton) for IQB; IQB reduced effluent by 79%.
     Predrying reduced the effluent to only 8% of that for pipe blanching.
     The BOD/N/P ratio averaged 97/4.8/1 (range 32-205/1.1-7.8/1) indicating
     that lima bean blancher effluent has an adequate nutrient balance for
                                  34

-------
biological waste treatment. The BOD/COD ratio was 0.76 (calculated
from Table A6).  Product yield figures indicate that lima beans re-
hydrate readily after the predrying step since the yield is greater
than that for the other steam blanching methods.  The difference
between the yield values for IQB-0 and 20 sec reflect product loss
and liquid loss in the hold section during IQB.  The only difference
between these two runs is the fact that the 20 sec experiment did
not include the hold section.  The liquid loss occurring in the hold
section is also reflected in the higher effluent generation value
reported for IQB-0 compared to 20 sec.  Deep bed steam blanching
resulted in the lowest yield and is partially accounted for in the
solids lost.  The other loss is accounted for in the decreased water
holding capacity of the surface due to a higher mass average tem-
perature of the deep bed blanched lima beans.

Results of the objective evaluation of lima beans is given in Table
13.  It can be seen that can vacuum of all of the steam blanched
samples is considerably lower than that for pipe blanched, canned
product.  This may have been due in part to can overfill in the
experimental samples.  Notice that most of the drained weights are
greater for the experimentally blanched samples indicating that the
can was overfilled.  Upon retorting the lima bean absorbs water and
expands.  This can result in decreased can vacuum.  Thus, the lower
can vacuum for the steam blanched samples does not necessarily re-
flect poor tissue gas removal.  The somewhat higher (8-10%) drained
weights for the steam blanched samples could be corrected by
filling at approximately 227-241 g.(8-8.5 ounces) rather than the
current 256 g. (9.0 ounces) fill weight.  Proper drained weight
would then be achieved following retorting and can vacuum would
probably be higher.

Although it was not recorded, there appeared to be more skins and
suspended solids in the IQB predried sample.  This was presumably
                             35

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        Table 13.  SUMMARY OF OBJECTIVE EVALUATION OF LIMA BEANS
Blanch-
ing
treat-
ment

IQB-5.0
IQB
20 Sec
Deep
bed
Pipe


IQB-5.0
IQB
20 Sec

Deep
bed
Pipe
Can Vacuum
(cm. Hg. vacuum)
Months of Storage
1 3
Avg.
15.0
15.7
12.7
12.4

29.7
Range
11.4-21.6
9.7-21.6
12.2-13.0
6.4-20.3

28.7-31.2
Avg.
17.0
17.8
17.0
16.3

30.5
Range
15.2-19.1
13.5-21.8
14.5-19.6
14.0-19.1

29.7-31.8
6 9
Avg.
17.0
18.8
17.8
13.7

28.7
Range
10.2-20.3
14.7-22.6
14.2-21.1
10.2-17.9

28.2-29,2
Avg.
14.7
16.3
15.7
14.5

27.4
Range
11.4-17.8
11.9-20.6
15.2-16.3
8.9-17.8

26.7-28.4
Drained Weight

395.3
307.3
296.8

341.7

324.0

381.4-413.6
299.6-315.0
277.8-315.8

338.7-343.5

298.2-364.9

568.3
J17.8
J03.6

J41.1

J07.9
(g.)
362.3-373.2
295.1-340.2
283.4-323.5

335.0-343.9

298.2-317.2
386.0
338.5
298.2

341.1

305.6
372.8-394.9
296.8-380.3
279.7-317.5
i
336.9-345.3

293.7-311.8

400.4
334.3
301.3

344.2

307.6

374.5-414.7
299.9-368.6
278.6-324.0

338.0-349.7

306.7-319.8
Each average consists of at least three observations.

       due to the rupture of skins during drying which were released during
       the agitated cook.  On this basis it is doubtful if IQB with pre-
       drying is an acceptable process.

       Subjective evaluation of lima beans is presented in Table 14.  There
       was no clear trend in preference for either steam blanched or pipe
       blanched product.  This probably reflects the fact that people
       usually do not have a specific idea of what good lima beans are
       supposed to taste or look like.  The conclusion can be made that
       there is probably a difference but that it was not a striking enough
                                    36

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     Table 14.  SUMMARY OF SUBJECTIVE EVALUATION OF LIMA BEANS
Blanching
treatment3
iqs-5.0
IOB-0
20 Sec
Deep Bed
IQB-0
20 Sec
Storage Timeb (months)
1369
0.17.
9-6-1
0.17.
8-10-0
57,
6-7-2
NS
NS
NS
0.17.
8-6-3
0.1%
7-8-2
NS
NS
0.17.
6-8-5
0.17.
7-4-7
17.
8-5-4
NS
1%
4-7-6
0.17.
8-4-9
NS
0.17.
6-5-5
NS
0.17.
5-4-11
0.17.
5-4-11
0.17.
5-4-11
NS
0.17.
4-6-6
IQB-5.0 means IQB with a 5.07. weight reduction prior to drying.
IQB-0 means IQB with no predrying.
30 Sec means heat only stage of IQB.
Deep bed means deep bed steam blanching.

Each sample was compared to a pipe-blanched, canned sample.  The control
was canned the same day as the experimental sample.  The top number is
the level of significance and the bottom three numbers  represent number
of judges preferring experimental sample, control and no preference,
respectively.  NS means no significant difference.
    difference to allow development of a preference.  There is no justi-

    fication for discarding any of the steam blanching methods based on

    subjective evaluation.


    In conclusion, IQB without predrying can be successfully applied to
    lima beans.  Adjustment must be made in fill weight to arrive at the

    correct drained weight since there is more rehydration in the can

    with IQB blanched beans.  Predrying results in a greater reduction

    in effluent generation; however, predrying adversely affects product

    quality due to skin splitting.
                                 37

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GREEN BEAN BLANCHING
     Table 15 presents a summary of the green bean blanching results.

          Table 15.  SUMMARY OF GREEN BEAN BLANCHING DATA3

Blanchine
treatment"
IQB-0
Deep bed
Pipe

Effluent
generation
(l./kkg)
163
125
334

BODr
(kg/kfcE)
1.0
0.55
--
Total
organic
nitrogen
(WkkK)
0.03
0.015
--

Total
phosphorus
Oca/kkK)
0.008
0.005
--

Product
yield
a)
94.0
97.3
--
Solids
lost as
product
(%)
1.16
0.89
--
 Expressed per kkg of blanched product.  See Tables A7 and A8 for
 complete data.  All pipe blanching analyses were discarded due to
 inappropriate sample storage.
 IQB-0 means IQB without predrying.
 Deep bed means deep bed steam blanching.
 Pipe means pipe blanching.
     In green bean blanching, steam blanching resulted in a 51-63%
     decrease in effluent generation compared to pipe blanching.   With
     green beans there was a different trend than with the previously
     blanched products.  In pea,  corn or lima bean blanching the  deep
     bed steam blanching treatment always resulted in a greater genera-
     tion of effluent.  With green beans the opposite is true; that is,
     deep bed blanching resulted  in less effluent than IQB-0.  This re-
     flects the peculiar nature of green bean blanching in that the
     maximum temperature reached  was 79 C (175 F).  In green bean blanch-
     ing, the bean must reach at  least 63 C (145 F) but must not  exceed
     82 C (180 F) in order to activate the enzyme pectin methyl esterase (PME)
     This enzyme, once activated, will cleave methoxy groups from pectin
     in the outer layer allowing  calcium-pectin interaction and conse-
     quently no sloughing.  In both deep bed and IQB the mass average
     temperature was between 77 C (170 F) and 82 C (180 F).  Consequently
                                  38

-------
there was no difference in the amount of steam required for heating.
Also, since there was no difference in temperature both treatments
should have resulted in equivalent surface water-holding capacity.
However, in deep bed steam blanching there was a greater water-
holding capacity in the bed itself resulting in less effluent drain-
ing from the process.
            g
Rails et al'.  reported effluent generation of 196 l./kkg (47 gal/ton)
for steam blanching and 7080 l./kkg (1700 gal/ton) for water blanch-
ing.  Both of these values are considerably higher than the IQB-0 and
Deep Bed reported here and, in the case of steam blanching, may be
due to blanching in 100 C steam rather than a steam-air mixture at
79-82 C (175-180 F).  The exceedingly high value for the water
blanching system may reflect the fact that batch-type experiments
were conducted and perhaps much more product could have been proc-
essed before the blancher water had to be changed.  Also, feed and
bleed systems may be more efficient from a waste generation stand-
point than straight batch systems.  Soderquist et al.   reported
446 l./kkg (107 gal/ton) for a rotary steam blancher.  This compares
quite favorably to the 334 l./kkg  (80 gal/ton) reported here for
pipe blanching.

The BOD/N/P ratio for green bean blancher effluent was 114/3.8/1
(range 105-129/2.7-7.4/1)indicating that the liquid waste stream
probably contains adequate nitrogen and phosphorus for biological
treatment.  Soderquist et al.   reported a BOD/N/P ratio of 109/6/1
for the rotary blanching operation and a BOD/COD ratio of 0.53.
Predrying was not attempted in this study since results in 1971
had shown that even with a 67. weight reduction skin rupture was
severe.  With predrying to less than 6%, the savings in effluent
                            i
                             39

-------
generation would not justify the cost of predrying.  Therefore,
predrying prior to IQB is not recommended for green beans.

Table 16 summarizes the objective evaluations performed on green
beans.  Can vacuum was noticeably lower for the two steam blanched
samples compared to pipe blanched samples.  This was probably due
to brine overfill in the experimentally blanched samples since the can
vacuum values do not follow any pattern with storage time.  If the
poor can vacuum had been due to presence of air cells in the green
bean tissue, the can vacuum values would have decreased upon storage.
Instead the can vacuum actually increased upon storage for the IQB
sample and fluctuated for the deep bed sample.  There was no sig-
nificant difference in drained weight between any of the treatments.
For slough and percent splits, however, IQB was definitely superior
to both deep bed steam blanching and pipe blanching.  These low
values are indicative that PME had been activated.  With deep bed
steam blanching the surface temperature of the tissue may have been
over 180 F for short periods of time resulting in PME inactivation.
Deep bed steam blanching compares favorably to pipe blanching.

Subjective evaluation of green beans is summarized in Table 17.
From these data it is apparent that there is no real preference for
product blanched in steam or hot water.  Even though the objective
tests indicated considerably less slough and percent splits for IQB,
the taste panel could not pick out that characteristic as a basis
for establishing preference.  This points out the fallacy of using
only objective or subjective tests to evaluate innovative or new
processing techniques.

In conclusion, IQB and deep bed steam blanching can be used to
blanch green beans prior to canning.  A steam-air mixture at 77-82 C
(170-180 F) is required to activate PME.  IQB produced 51 percent

                             40

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                Table 16.  SUMMARY OF OBJECTIVE EVALUATION OF GREEN BEANS0
                                       Can Vacuum
                                    (cm. Hg. vacuum)
Blanching
treatment
IQB
Deep Bed
Pipe
IQB
Deep Bed
Pipe
IQB
Deep Bed
Pipe
IQB
Deep Bed
Pipe
Aver.
1.0
0.8
17.0
1
Range Aver .


15
0-5.1
0-1.3
.2-17.8
0.0
6.9
16.3
Months of Storage
3
Range Aver .
0-0
2.5-12.7
12.7-19.1
3.1
1.5
17.0
6


16
Range Aver .
0-7.6
0-7.6
.5-17.8
4.1
8.9
17.0
9
Range

5
16
0-8.9
.1-14.0
.5-19.1
Drained Weight
(a)
264.1
274.3
276.3
262
272
265
.8-265.2
.4-275.6
.7-282.8
266.6
275.8
241.6
260.6-272.2
273.2-279.1
240.9-242.7
270.5
275.6
287.1
266
273
283
.2-272.8
.8-276.6
.8-293.0
269.3
279.8
293.5
268
278
292
.4-270.5
.8-281.3
.9-294.2
Slough
(%)
4.0
13.5
7.8
3
12
6
.0-5.0
.0-15.0
.5-9.0
8.0
16.0
16.0
8.0-8.0
14.0-18.0
16.0-16.0
7.0
16.0
11.0
7
15
9
.0-7.0
.0-17.0
.0-13.0
10.0
15.0
15.0
9
15
14
.0-11.0
.0-15.0
.0-16.0
Splits
(%)
5.0
32.5
52.5
5
30
35
.0-5.0
.0-35.0
.0-70.0
2.5
30.0
55.0
0-5.0
25.0-35.0
50.0-60.0
5.0
35.0
22.5
5
30
20
.0-5.0
.0-40.0
.0-25.0
15.0
22.5
55.0
10
20
55
.0-20.0
.0-25.0
.0-55.0
Each average consists of at least three observations.

               less effluent than pipe blanching and resulted in considerably less
               slough and percent splits.  Organoleptically, the steam blanched
               products were quite acceptable.
                                           41

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     Table 17.  SUMMARY OF SUBJECTIVE EVALUATION OF GREEN BEANS

Blanching
treatment3

IQB-0

Deep bed
Storage time0
(months)
1 369
0.17.
10-5-5

NS
5%
6-3-4
17.
5-6-3

NS
17.
5-8-3
57.
6-6-4
17.
5-6-6
 IQB-0 means IQB without predrying.
 Deep bed means deep bed steam blanching.

 Each sample was compared to a pipe-blanched, canned control.   The con-
 trol was canned the same day as the experimental sample.  The top number
 is the level of significance and the bottom three numbers represent
 number of judges preferring experimental sample, control and  no prefer-
 ence, respectively.  NS means no significant difference.
POTATO BLANCHING

     Potato blanching data are summarized in Table 18.

            Table 18.  SUMMARY OF POTATO BLANCHING DATA2

Blanching
treatment" ,
IQB-6.9
IQB-0
Deep bed

Effluent
generation
(l./kks)
100
171
167

BOD5
(kg/kkg)
0.5
0.75
0.65
Total
organic
nitrogen
(kg/kkg)
0.03
0.05
0.065

Total
phosphorus
(kg/kkg)
0.0085
0.012
0.017

Product
yield
(7.)
93.1
93.4
93.8
Solids
lost as
product
a)
0.43
0.60
0.61
 Expressed per kkg of blanched product.   See Tables A9 and A10 for
 complete data.

 IQB-6.9 means IQB with a 6.9% weight reduction prior to blanching.
 IQB-0 means IQB without predrying.
 Deep bed means deep bed steam blanching.
                                  42

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Since potatoes are not normally blanched following slicing or dicing
there is no water blanching method to which to compare the steam
blanching method.  However, these experiments were included for
those processors who both can and freeze or dehydrate potatoes.
Prior to freezing or dehydration, potatoes may be blanched.  The
data for effluent generation are quite similar to those presented
for corn and reflect  the water-holding capacity of the cut potato
surface.  The ZODc generated per ton of product is quite low sug-
gesting that most of the free surface cellular juices were washed
off the potato prior to blanching.  This prewashing was accomplished
by transporting the potatoes to the laboratory under water and then
washing them again in the pilot plant.  Deep bed and IQB-0 resulted
in nearly the same effluent generation.  This was due to the fact
that peroxidase inactivation in the potato slice required a heat
time of 60 seconds resulting in a mass average temperature near 93 C
(200 F).  Thus, compared to deep bed steam blanching where the mass
average temperature was between 93-99 C (200-210 F), there would be
little difference in the total steam condensed.  Consequently, there
was little difference between deep bed and IQB.  The heat only sec-
tion of the IQB process was not run with potatoes or any of the root
crops.  This was not run since it had been observed in earlier trials
that IQB-0 and the heat-only runs did not differ significantly in
effluent generation since little effluent was released in the hold
section.  Also, for the root crops blanching is usually required
prior to freezing to partially cook the product.  Under these cir-
cumstances the heat-only method would probably not be adequate as a
blanching technique.

The BOD/N/P ratio for potato blancher effluent was 57/3.9/1 (range
37-66/3.6-4.2/1) Indicating that adeuqate nutrients are available for
biological treatment.  The BOD/COD ratio averaged 0.90.
                             43

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              Objective analysis of the potato blanching trials is summarized in
              Table 19.  The lower can vacuum for the steam blanched samples is
              attributed to overfill rather than incomplete tissue gas removal.
                 Table 19.  SUMMARY OF OBJECTIVE EVALUATION OF POTATOES3

Blanching,
treatment
IQB-6.9
IQB
Deep Bed
Control

IQB-6.9
IQB
Deep Bed
Control
Can Vacuum
(cm. Hg. vacuum)
Aver.
12.2
12.4
9.4
22.4

334.6
343.6
345.1
312.4
1
Range Aver.
8.9-16.5
10
3
16

332
335
334
285
.2-19.1
.8-11.4
.5-27.9
7.9
7.8
8.6
17.3

.2-335.0
.0-352.9
.4-352.8
.7-335.4
330.6
330.9
244.9
286.6
Months of Storage
3
Range Aver.
5.1-10.2
5.1-11.4
6.4-12.7
14.0-25.4
10.9
12.7
11.7
18.5
Drained Weight
(g)
326.1-333.8
320.7-335.7
328.4-356.2
274.2-301.3
338.2
336.3
340.5
311.3
6
Range Aver .
7.6-15.2
7
10
12

331
328
328
292
.6-17.8
.2-17.8
.7-24.1
12.2
10.9
16.0
20.6

.4-342.9
.8-340.4
.3-358.1
.6-350.8
333.1
336.0
337.4
308.4
9
8
7
14
15

328
325
330
283
Elange
.9-16.5
.6-15.2
.0-19.1
.2-25.4

.6-336.8
.3-343.9
.4-343.7
.1-357.1
Each average consists of at least three observations.
Control samples were not blanched prior to canning.  The whole potato was treated
in hot water and steam before peeling.
         The higher drained weights for the steam blanched samples show an over-
         fill of about 28 g. (one ounce).   Thus, instead of filling at a 312 g.
         (11 ounce) fill weight, a 284 g.  (10 ounce) fill weight would be suf-
         ficient.

         Table 20 presents a summary of the subjective evaluations on potatoes.
         The IQB predried blanching technique was not acceptable due to darkening
         of the potato surface during air  drying.  This is evidenced by the low
         preference for the IQB-predried sample.  With IQB and deep bed steam
                                          44

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     Table 20.  SUMMARY OF SUBJECTIVE EVALUATION OF POTATOES
Blanching
treatment3

IQB-6.9

IQB-0

Deep bed
Storage time15
(months)
1369
5%
2-9-3

NS
0.1%
4-9-3
0.1%
4-6-8

NS

NS
1%
5-5-6

NS

NS

NS
1%
4-8-5
1%
8-5-2
IQB-6.9 means IQB with a 6.9% weight reduction prior to blanching.
IQB-0 means IQB without predrying.
Deep bed means deep bed steam blanching.
Each sample was compared to a control sample.  The control was canned
the same day as the experimental sample.  The top number is the level
of significance and the bottom three numbers represent number of judges
preferring experimental sample, control and no preference, respectively.
NS means no significant difference.
    blanching there was very little difference in samples as evidenced
    by the taste panel results.  However, when the products were com-
    pared in large quantity batches (for example, a can full), the steam
    blanched product appeared somewhat darker than the pipe blanched.
    This was believed due to darkening of the potatoes in transport to
    the laboratory.   The importance of this slight darkening is not
    readily apparent since the taste panel showed no preference.
    In conclusion, IQB without predrying can be successfully applied to
    potato blanching.  At the loading rates used in this study, IQB
    offered little advantage over deep bed steam blanching.  However,
    at greater loading rates IQB would fee expected to produce sig-
    nificantly less effluent than deep bed steam blanching.  The IQB
    blanched product was equivalent to conventionally canned product.
    Predrying is not recommended due to surface darkening during air
    dehydration.
                                 45

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BEET BLANCHING
     The beet blanching data are summarized in Table 21,

             Table 21.  SUMMARY OF BEET BLANCHING DATA*1

Blanching
treatment**
IQB-5.6
IQB-0
Deep bed

Effluent
generation
a./kkit)
196
229
225

BODs
(kg/kkO
5.75
4.95
4.8
Total
organic
nitrogen
(kg/kkg)
0.11
0.085
0.11

Total
phosphorus
(kg/kkg)
0.0285
0.022
0.0305

Product
yield
(%)
86.3
89.4
88.9
Solids
lost as
product
(%)
5.21
4.02
5.26
 Expressed per kkg of blanched product.  See Tables All and A12 for
 complete data.
 IQB-5.6 means IQB with a 5.6% weight reduction prior to blanching.
 IQB-0 means IQB without predrying.
 Deep bed means deep bed steam blanching.
     As with potatoes  sliced  beets  are  not  normally blanched  prior  to
     canning and,  therefore,  there  is no  conventional  blanching  operation
     for comparison.   Generally it  is assumed  that  blanching  will be
     accomplished  in the  steam treatment  and/or hot water  process just
     prior to peeling. Frequently, however, the  center  temperature of
     the beet is not in the range to inactivate enzymes.   When this is
     the case, delay in getting the sliced  or  diced beets  in  the can may
     result in darkening  of the beet.   This is undesirable.   The beet
     slices that were  obtained from the canning plant  for  this study had
     positive peroxidase  activity prior to  the steam blanching runs.

     The data in Table 21 reveal several  important  characteristics  of
     beet blanching.   First,  the effluent generation values are  nearly
     the same as those reported for pea blanching.   The high  effluent
     generation values, however, are the  result of  cellular losses  rather
                                  46

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than inability of-the beet surface to hold surface moisture.  The
BOD values are the highest of those reported in this study as are
the "solids lost as product" figures.  This indicates that beet
tissue is very susceptible to heat damage.  Consequently, any method
of blanching will result in high solids loss from the tissue.  For
                        0
comparison, Rails et al.  reported 317 l./kg (76 gal/ton) for steam
blanching of beets and 5550 l./kkg (1330 gal/ton) for water blanch-
ing.  Comparing IQB to those results, IQB would reduce liquid waste genera-
tion by about 28%.  As with green beans, the 5550 l./kkg (1330 gal/
ton) is probably unduly large since presumably more product could
have been run through the blancher, lowering the effluent value.
Fredrying the beet surface prior to IQB resulted in a further de-
crease in effluent generation; however, during air drying some
darkening did occur.  This was undesirable and resulted in a low
preference for that treatment.

The BOD/N/P ratio averaged 208/3.8/1 (range 158-292/3.6-4.0/1) indi-
cating that beet blancher water maybe low in nitrogen for biological
waste treatment.  The BOD/COD ratio averaged 0.97 slightly higher
than the 0.87 reported by Soderquist et al.

Objective evaluation of beets resulted in the data summarized in
Table 22.  The can vacuum was lower for all the steam blanched
samples compared to control.  Examination of the drained weight
data shows that the experimental samples contained at least 56 g.
(two ounces) more than the control and were overfilled.  Instead of
using the 312 g. (11 ounce) fill weight, the fill weight could have
been 256 g. (9 ounces).  The drained weight data show that in the
can the beet will lose tissue juices during the-retorting operation
and consequently the drained weight is less than the fill weight.
By blanching prior to canning the juice is lost before the beet is
put in the can.  From a canner's point of view it is best not to

                             47

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               blanch prior to canning since then he has to clean up the blancher
               effluent.  Without blanching, the effluent ends up in the can  and
               eventually ends up in the kitchen where the housewife disposes of
               it.  On the other hand, if the canner has difficulty making drained
               weight on canned beets, then blanching prior to canning will allow
               him to more nearly match fill weight to drain weight.
                   Table 22.  SUMMARY OF OBJECTIVE EVALUATION OF BEETS3
Blanching
treatment*
IQB-5.6
IQB
Deep Bed
Control

IQB-5.6
IQB
Deep Bed
Control
Can Vacuum
(cm. Hg. vacuum)
Aver.
10.4
11.9
10.4
22.9

330.3
327.5
326.3
265.5
1
8
7
6
16

327
323
323
249
Range Aver .
.9-11.4
.6-15.2
.4-12.7
.5-33.0
7.9
6.4
5.1
16.3

.2-331.4
.4-332.3
.8-327.0
.7-281.0
329.7
325.7
329.2
262.1
Months of Storage
3
Range Aver.
5.1-15.2
5.1-7.6
5.1-5.1
10.2-22.9
8.6
4.6
6.1
15.0
Drained Weight
(g)
326.6-330.8
320.3-328.2
320.8-332.7
240.5-279.0
329.2
332.3
336.3
250.2
6
5
2
2
11

327
328
328
218
Range Aver.
.1-10.2
.5-5.1
.5-10.2
.4-19.1
5.8
7.6
12.4
16.8

.6-330.8
.3-338.0
.3-340.0
.0-266.5
332.8
329.4
332.8
259.6
9
5
5
7
10

329
323
325
244
Range
.1-8.9
.1-10.2
.6-15.2
.2-20.3

.8-334.9
.1-337.8
.1-339.1
.1-288.5
Each average consists of at least three observations
Control samples were not blanched prior to canning.   The whole  beet was  treated
in hot water and steam before peeling.
               Table 23 presents a summary of the subjective evaluations of beets.
               The predried beets were definitely of poorer quality than the con-
               trol, the primary difference being the darker color of the predried
               samples.  For the other steam blanching methods no consistent dif-
               ference was found.
                                             48

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        Table 23.  SUMMARY OF SUBJECTIVE EVALUATION OF BEETS
Blanching
treatment3

IQB-5.6
IQB

Deep bed
1
1%
4-7-4
NS
1%
6-6-4
Storage timeb
(months)
3,6 9

NS
NS

NS
1%
3-7-4
NS
0.17.
2-15-1
0.1%
4-7-11
NS

NS
 IQB-5.6 means IQB with a 5.6% weight reduction prior to blanching.
 IQB-0 means IQB without predrying.
 Deep bed means deep bed steam blanching.
 Each sample was compared to a control sample.  The control was canned
 the same day as the experimental sample.  The top number is the level of
 significance and the bottom three numbers represent number of judges
 preferring experimental sample, control and no preference, respectively.
 NS means no significant difference.
     In conclusion, IQB without predrying is an effective way of blanch-
     ing beets with reduced effluent generation.  Beet tissue is extremely
     sensitive to high temperatures resulting in loss of tissue juice.
     Predrying reduces effluent further; however, product quality is ad-
     versely affected.  Blanching prior to canning would be an effective
     way to insure meeting drained weights for beets.
CARROTS
     Carrot blanching data are summarized in Table 24.  Carrots, like
     other root crops, beets and potatoes, are not normally blanched
     after slicing or dicing unless they are to be frozen or dehydrated.
     Therefore, there was no commercial blanching operation to monitor
     in this study.  Even though the whole carrot receives a hot water
     and steam treatment prior to peeling, peroxidase activity was still
     present in the sliced carrots.  The values in Table 24 for effluent
                                  49

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           Table 24.  SUMMARY OF CARROT BLANCHING DATA'
Blanching
treatment13
IQB-0
Deep bed
Effluent
generation
(l./kkg)
192
225
BOD5
(kg/kkg)
2.0
2.6
Total
organic
nitrogen
(kg/kkg)
0.10
0.14
Total
phosphorus
(kg/kkg)
0.016
0.023
Product
yield
a)
91.8
88.4
Solids
lost as
product
a)
1.93
2.77
Expressed per kkg of blanched product.  See Tables A13 and A14 for
complete data.
IQB-0 means IQB without predrying.
Deep bed means deep bed steam blanching.
    generated are similar to the others reported in this study.  Pre-
    drying would be expected to reduce blancher effluent even further.
                                           3
    In the original studies by Lazar et al.  carrots predried to a
    5.8% weight reduction produced only half as much effluent as IQB
    without predrying.  The product yield values reported here indi-
    cated that the carrot surface loses some of its moisture-holding
    capacity as the surface temperature is increased since the losses
    are in excess of those calculated from solids loss.  The BOD/N/P
    ratio averaged 122/6.3/1 (range 117-126/6.1-6.7/1) indicating that
    carrot blancher effluent has adequate nutrients for
    biological waste treatment. The BOD/COD ratio was 0.87.

    Table 25 presents the results on the objective evaluation of
    carrots.  There was no significant difference in either the can
    vacuum or drained weights when steam blanched samples were compared
    to control samples.

    Subjective evaluation results for carrots are shown in Table 26.
    The preference of the taste panel for the control sample is markedly
    evident in these data.  This serves to illustrate the importance of
                                 50

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               Table 25.  SUMMARY OF OBJECTIVE EVALUATION OF CARROTS
                                     Can Vacuum
                                  (cm. Hg. vacuum)
Blanching,
treatment
IQB
Deep bed
Control

IQB
Deep bed
Control
Aver.
9.1
11.7
9.1
1
7
8
7
Months of Storage
3
Range Aver. Range Aver.
.6-11.4
.9-15.2
.6-11.4
7.9
10.9
7.1
7.6-8.9
7.6-12.7
3.8-8.9
9.9
8.1
7.9
6
5
2
2
Range Aver.
.1-16.5
.5-15.2
.5-12.7
13.7
14.0
10.9
9
12
12
10
Range
.7-15.2
.7-15.2
.2-12.7
Drained Weight
(g) f
284.0
293.9
267.5
280
291
259
.1-285.5
.1-295.4
.4-274.7
286.6
292.5
265.5
284.0-288.8
290.7-293.4
262.5-277.7
284.3
290.5
280.6
281
285
272
.4-287.9
.9-293.2
.4-292.2
283.1
293.7
278.3
278
291
273
.1-286.6
.5-295.2
.0-284.8
Each average consisted of three observations.

Control samples were not blanched prior to canning.   The whole carrot was treated in
hot water and steam before peeling.
                 Table 26.  SUMMARY OF SUBJECTIVE EVALUATION OF CARROTS
Blanching
treatment3
1 3
Storage time"
(months)
6
9

IQB

Deep bed
0.1%
0-11-5
0.1%
2-11-7
0.1%
6-13-7
0.1%
5-10-6
0.1%
5-12-3
0.1%
4-11-5
0.1%
1-9-10
0.1%
2-8-10
           IQB means IQB without predrying.
          .Deep bed means deep bed steam blanching.
           Each sample was compared to a control sample.  The control was canned
           the same day as the experimental sample.  The top number is the level of
           significance and the bottom three numbers represent number of judges
           preferring experimental sample, control and no preference, respectively.
                                             51

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     color in product evaluation.  The steam blanched carrots were trans-
     ported to the laboratory and there was considerable darkening of the
     tissue even though it was held under water.  The taste panel preferred
     the brighter orange color of the control.  In the study by Lazar et
        3
     al.  IQB samples were judged to be better than the conventionally
     steam blanched product.  In the opinion of most of the judges the only
     difference between samples in the present study was color.

     In conclusion, IQB can be used to blanch carrots prior to canning,
     freezing or dehydration.  There was no adverse effects of the steam
     blanching treatment on carrots prior to canning.  Blanching of carrots
     prior to canning could be recommended if there are unduly long delays
     between cutting and can filling.  During this delay color changes
     could occur.

LOADING RATE AND SIZE OF COMMERCIAL IQB UNITS
     One of the basic principles inherent in-IQB is that each piece of
     vegetable receives the same thermal energy as every other piece.  If
     there is some condition which alters exposure time or rate of heat
     transfer to the surface of the vegetable, then there is the possi-
     bility of underblanching.  In heat transfer the total quantity of
     heat transferred is directly proportional to the exposed surface
     area.  Loading conditions which will decrease total surface exposed
     may result in underprocessing and therefore belt loading rate is an
     extremely important variable in the IQB process.

     The belt loading rates for the heat belt, hold belt and deep bed
     steam heating belt were calculated based on through-put, residence
     time and belt dimensions.  The results for each run are given in
     the Appendix.
                                  52

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To summarize the data, the following observations can be made:  1)
Heat belt loading--for the IQB process the heat belt was loaded at
                      2          2
approximately 4.9 kg/m  (1 Ib./ft ). ' For these products this would
be optimal loading for exposing each piece to the steam conditions
in the heat section.  This loading was recommended in previous publi-
              o
cations on IQB .     For beets and carrots, belt loadings were some-
what higher, generally 6.3 to 9.8 kg/m2 (1.3 to 2.0 Ib./ft ).  With
these two products higher product loading rates could be used since
medium slices (3.2-4.4 cm. diameter by 0.64 cm. thick) did not pack
and reduce heat transfer surface area as much as other product forms
(i.e. peas, corn, lima beans, or green beans).  With deep bed blanch-
ing, loading rate was limited by configuration of the equipment.  The
deep bed was 5.1 to 6.4 cm. (2 to 2.5 inches) deep resulting in dif-
                                                                    2
ferent loading rates depending on product geometry:  peas--12.9 kg/m
(2.65 lb/ft2); corn--14.5 kg/m2 (2.98 lb/ft2); lima beans—14.8 kg/m2
(3.04 lb/ft2); green beans—7.03 kg/m2 (1.44 lb/ft2); potatoes —
11.8 kg/m2 (2.41 lb/ft2); beets—16.4 kg/m2 (3.36 lb/ft2) and carrots—
         2            2
16.0 kg/m  (3.28 lb/ft ).  Green beans had the lowest product density
in the deep bed.  This would be expected since cylinders with a
length to diameter ratio of 3:1 have a very low packing density.  2)
Hold belt loadings —in the IQB process hold belt loadings varied
from 17.6 kg/m2  (3.6 lb/ft2) for potatoes to 69.3 kg/m2 (14.2 lb/ft2)
for green beans.  Hold section belt loading reflects the compounding
effect of many variables including ratio of heat residence time to
hold residence time, ratio of heat belt width to hold belt width,
and ratio of heat section length to hold section length.  For our
system the heat and hold belts were nearly the same width [21.6 cm
(8.5 inch) wide heat belt; 20.3 cm (8.0 inch) wide hold belt] and
the length ratio was 3/1 [i.e. 91.4 cm (3 ft) heat section/30.5 cm
(1 ft) hold section].  The ratio of heat belt loading to hold belt
loading should, under these conditions, be equal to the ratio of the
lineal velocity of the hold belt to the lineal velocity of the heat
belt.
                             53

-------
     loading rate heat belt\ _ | lineal velocity hold belt
     loading rate hold belt I   1 lineal velocity heat belt
The lineal velocity is the length of the belt divided by the resi-
dence time in the section and since L(Heat)/L(Hold) = 3/1, the load-
ing rate on the heat belt/loading rate on the hold belt is:

   _	 	Heat       /  1  \  residence time in heat section
    (Loading rate)u . .       I  3  /  residence time in hold section
                  Ho la
                             or
    (L-R')Heat                 Heat
    (L'R')Hold        3     r Hold

where L.R.  -  loading rate,  kg/m2
and    ?•   -  residence time, seconds.
Using heat/hold times reported in this study, the size of a commer-
cial belt-type IQB unit was calculated and is given in Table 27.  A
                                  2         2
heat belt loading rate of 4.9 kg/m  (1 Ib/ft ) and a hold belt
                       2          2
loading rate of 49 kg/m  (10  Ib/ft ) was assumed.  Blanch times are
the same as those reported in Table 3.  For commercial units it
would be expected that costs  for an IQB blancher of this configura-
tion would not be more than that for rotary-type water blanchers of
comparable production capacity.  Compared to conventional steam
blanchers, IQB would be less costly since the IQB unit is consider-
ably shorter for the same production capacity.

Regarding developments of hardware for IQB units, the engineering
research team at Western Regional Research Laboratory, USDA,
Berkeley, recently reported   on the development of a prototype
IQB unit using spiral vibrating conveyors.  High production rates,
compactness, simplicity and control of residence time were claimed
                             54

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for the unit.  A larger prototype is planned  for construction.
        Table 27.  ESTIMATED IQB PRODUCTION UNITS
                                                 a
Product
Peas
Corn
Lima beans
Green beans
Potatoes
Carrots
Beets
Production rate
(kkg product/hr) (tons product/hr)
9.1
13.6
13.6
13.6
4.5
5.7
5.7
10
15
15
15
5
6.3
6.3
a
 Heatl.52in(5 ft) wide x 9.14 m  (30 ft)  long  loaded at
 4.9 kg/m2 (1 lb/ft2).

 Hold 1.52 m  (5 ft) wide x 1.37 m  (4.5 ft)  long  loaded  at
 49 kg/m2 (10 lb/ft2).
                              55

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                            SECTION VII
                 UNITS FOR INTERCONVERSION OF DATA
To aid in the interconversion and increased digestibility of data con-
tained in this report, several important conversion factors are pre-
sented in the following table:

           Table 28.  FACTORS FOR INTERCONVERSION OF DATA
To convert from:
cm
g
kkg
kg/m2
cm
l./kkg
kg/kkg
l./hr
l./case
To:
ft.
ounces
ton
lb/ft2
in.
gal /ton
Ib/ton
gal/hr
gal/case
Multiply by:
0.0328
0.0353
1.103
0.205
0.394
0.240
2.00
0.264
0.264
All of the values contained in this report based on the amount of
product were calculated based on the amount of product (kkg or ton)
processed.  It is frequently desirable to know effluent generation
based on plant input rather than plant output.  Therefore, to facili-
tate these calculations the following are given:
                                  56

-------
                  Table 29.  CANNING YIELD FACTORS
Pounds product Cases
Product
Peas
Corn
Lima beans
Green beans
Potatoes
Beets
Carrots
case
15.5
15.75
13.5
13.5
16.5
16.5
14.6
ton raw product
115
32
130
125
75
70
65
Ton raw product
ton processed product
1.13
3.97
1.14
1.19
1.62
1.73
2.10
o
 Calculated based on fill weight.
b
 Reference 12.
                                  57

-------
                            SECTION VIII
                             REFERENCES

1.  Weckel, K. G., R. S. Rambo, H. Veloso, and J. H. von Elbe.  Vegetable
    Canning Process Wastes.  Res. Rpt. No. 38.  College of Agricultural
    and Life Sciences, Univ. Wisconsin-Madison, p. 1-20, 1968.
2.  National Canners Association.  Res. Information Bull. No. 170,
    January 1971.
3.  Lazar, M. E., D. B. Lund and W. C. Dietrich.  IQB:  A New Concept in
    Blanching.  Food Tech. 25:684-686, July 1971.
4.  Lund, D. B., S. L. Bruin, Jr., and M. E. Lazar.  Internal Temperature
    Distribution During Individual Quick Blanch.  J. Food Sci. 37:183,
    January 1972.
5.  Lund, D. B.  A Field Study on the Application of Individual Quick
    Blanch.  In:  Proceedings Third National Symposium on Food Processing
    Wastes.  Washington, D. C., U. S. Government Printing Office.   EPA-
    R2-72-018,  1972.
6.  Standard Methods for the Examination of Water and Waste Water.  13th
    ed.  New York,  Amer. Publ. Health Assoc.,  Inc., 1790 Broadway, 1971.
7.  Van Buren, J. P., J. C. Moyer, D. E. Wilson, W. C. Robinson, and
    D. B. Hand.  Influence of Blanching Conditions on Sloughing, Splitting
    and Firmness of Canned Snap Beans.  Food Tech. 14:233, 1960.
8.  Rails, J. W., H. J. Maagdenberg, N. L. Yacoub, and W. A. Mercer.
    Reduced Waste Generation by Alternate Vegetable Blanching Systems.
    In:  Proceedings Third National Symposium on Food Processing Wastes.
    Washington, D.  C., U.  S. Government Printing Office.  EPA-R2-72-018,
    1972.  p. 25-70.
                                  58

-------
                       REFERENCES  (continued)
 9.   Lee, F. A.   The Blanching Process.   In:   Advances  in Food  Research.
     Vol. 8.  New York, Academic Press., 1958.  p.  63.
10.   Soderquist, M.  R., G.  I.  Blanton and D. W.  Taylor.   Characterization
     of Fruit and Vegetable Processing Waste Waters.   In:  Proceedings
     Third National  Symposium on Food Processing Wastes.   Washington,
     D. C., U. S. Government Printing Office.   EPA-R2-72-018, 1972.
     p. 409-436.
11.   Brown, G. E.  Personal Communication and  paper presented at the
     Annual Meeting  Institute of Food Technologists,  Miami Beach,
     June 1973.
12.   	.  1971-1972 Yearbook.  Canner Packer.   140:9, 1971.  p. 102.
                                  59

-------
                         SECTION IX
                    LIST OF PUBLICATIONS

Lund, D. B.  The Individual Quick Blanching Process.   Michigan State
University.  Highlights in Food Science, March 1973.
Lund, D. B.  Impact of the Individual Quick Blanch (IQB)  Process on
Cannery Waste Generation.  Presented at the Fourth National Sym-
posium on Food Processing Wastes, Syracuse, New York, April 1973.
Lenz, M. K. and D. B. Lund.  Lethality Calculations for Heat/Cool
Processes by the L-Fo Method.  Submitted to J. Food Science, 1973.
                              60

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                               Section X

                          Appendix - Raw Data



                                                                  Page

Al     Individual Blanching Trials for Peas                        62

A2     Characteristics of Effluents Generated During Pea           63
       Blanching

A3     Individual Blanching Trials for Corn                        65

A4     Characteristics of Effluents Generated During               66
       Corn Blanching

A5     Individual Blanching Trials for Lima Beans                  68

A6     Characteristics of Effluents Generated During               69
       Lima Bean Blanching

A7     Individual Blanching Trials for Green Beans                 71

A8     Characteristics of Effluents Generated During               72
       Green Bean Blanching

A9     Individual Blanching Trials for Potatoes                    73

A10    Characteristics of Effluents Generated During               74
       Potato Blanching

All    Individual Blanching Trials for Beets                       75

A12    Characteristics of Effluents Generated During               76
       Beet Blanching

A13    Individual Blanching Trials for Carrots                     77

A14    Characteristics of Effluents Generated During               78
       Carrot Blanching
                                   61

-------
        Table Al.  INDIVIDUAL BLANCHING TRIALS FOR PEAS
^
Blanching
treatment
IQB-6.25-4-A1S
lQB-O-4-Als
30 Sec-4-Als
Deep bed-4-Als
IQB-7.0-3-Ala
lQB-O-3-Ala
30 Sec-3-Ala
Deep bed-3-Ala
IQB-7.5-Perf.
lQB-0-Perf.
30 Sec- Per f .
Deep bed- Per f.
Averages
IQB-6.9
IQB-0
30 Sec
Deep bed
Treat-
ment
number
IP
2P
3P
4P
5P
6P
7P
8P
9P
10P
IIP
12P





Belt loading
Heat
(kg/m2)
5.08
5.42
5.42
13.13
4.49
4.39
4.20
13.52
5.42
5.86
5.22
12.20

5.00
5.22
4.93
12.93
Hold
(kg/m2)
24.20
25.82
—
—
21.52
20.94
—
—
25.91
28.01
—
—

23.86
24.94
—
—
Effluent
generation
(l./case)
1.09
1.76
1.51
2.15
0.913
1.47
1.39
2.15
1.10
1.51
1.51
2.29

1.04
1.58
1.47
2.19
Product
yield
(%)
88.8
87.5
90.0
83.8
90.0
90.5
91.3
83.8
87.5
90.0
90.0
82.5

88.8
89.3
90.4
83.3
Solids lost
as product
(%)
1.37
1.57
2.10
3.31
1.14
2.51
1.85
2.77
2.10
2.12
2.33
3.26

1.53
2.07
2.09
3.11
IQB-6.25 means IQB with a 6.25% weight reduction prior to blanching.
IQB-0 means IQB without predrying.
30 sec means heat only stage of IQB.
Deep bed means deep bed steam blanching.
4 or 3 refers to sieve size; perfection was sieve size 3, 4 and 5.
Als means Alsweet; Ala means Alaskan; Perf. means Perfection.
                               62

-------
Table A2.  CHARACTERISTICS OF EFFLUENTS GENERATED DURING PEA BLANCHING
a
Treatment
number
IP
2P
3P
4P
5P
6P
7P
8P
9P
10P
IIP
12P
Pipe
Pipe
Averages
IQB-6.9
IQB-O
30 Sec
Deep bed
Pipe
BOD5
(ppnu
9730
7260
11300
13200
10300
15800
10500
13400
15600
11400
13600
14200
8300
7500

11900
11500
11800
13600
7900
Total
solids
00
1.99
1.43
2.16
2.58
1.94
2.66
2.04
2.16
3.06
2.18
2.40
2.44
1.54
1.42

2.33
2.09
2.20
2.39
1.48
Total
phosphorus
(ppm)
82
77
107
113
164
215
167
174
195
154
162
189
150
105

147
149
145
159
128
Total organic
nitrogen
(ppm)
414
294
485
596
548
768
612
678
893
684
747
824
463
433

618
582
615
699
448
                                 63

-------
               Table  A2  (continued).   CHARACTERISTICS  OF
               EFFLUENTS  GENERATED DURING PEA BLANCHING
Treatment
number
IP
2P
3P
4P
5P
6P
7P
8P
9P
10P
IIP
12P
Pipe
Pipe
Averages
IQB-6.9
IQB-0
30 Sec
Deep bed
Pipe
Volatile
solids
(ppm)
18000
13000
19600
23500
17300
23400
18200
19200
27100
19200
21200
21600
13400
12200

20800
18500
19700
21400
12800
Suspended
volatile
solids
(ppm)
644
476
595
581
329
547
473
389
2170
1120
1230
991
200
775

1050
713
765
654
488
Suspended
solids
(%)
.066
.055
.069
.070
.034
.058
.052
.050
.224
.119
.132
.108
.025
.087

.108
.077
.084
.076
.056
Soluble
phosphorus
(ppm)
37
30
46
55
75
113
102
99
101
1 84
94
91
77
52

71
76
81
82
65
Nitrogen
NH3
(ppm)
20
15
19
27
24
28
16
22
37
32
32
37
25
36

27
25
23
29
31
NO
NO 2
(ppm)
1.0
0.7
0.6
0.6
0.9
0.8
0.6
0.6
0.6
0.7
0.6
1.0
0.6
0.9

0.8
0.7
0.6
0.7
0.8
N02b
(ppm)
~
—
M w
^ ^
.16
.08
.05
.05
—
—
—
M V
.09
—

.16
.08
.05
.05
.09
pH
7.0
7.0
7.0
7.0
6.6
6.9
6.9
6.9
6.8
7.0
6.9
6.9
7.7
7.3

6.8
7.0
6.9
6.9
7.5
See footnote and treatment number on Table Al.
blanching.
Pipe means pipe
No value indicates too small to be measured.
                               64

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        Table A3.   INDIVIDUAL BLANCHING TRIALS  FOR CORN
Blanching
treatment
IQB-7.5
IQB-0
20 Sec
Deep bed
IQB-7.5
IQB-0
20 Sec
Deep bed
IQB-7.5
IQB-0
20 Sec
Deep bed
Averages
IQB-7.5
IQB-0
20 Sec
Deep bed
Treatment
number
1C
2C
3C
4C
5C
6C
7C
8C
9C
IOC
11C
12C





Belt loading
Heat
(kg/n3
4.73
4.39
4.39
12.40
5.66
3.81
4.39
16.40
6.30
5.12
5.12
14.84

5.56
4.44
4.64
14.54
Hold
(kg/m2)
22.59
20.94
—
--
27.08
18.30
—
—
30.11
24.40
—
—

26.60
21.23
—
—
Effluent
generation
(l./case)
.489
.978
.822
1.17
.644
.921
1.00
1.20
.728
.819
.826
1.11

6.22
.906
.883
1.16
Product
yield
(°/\
\ i°)
94.7
96.3
98.1
94.1
92.8
96.9
95.9
93.8
91.9
98.1
98.1
94.9

93.1
97.1
97.4
94.2
Solids lost
as product
a)
.50
1.43
1.00
1.90
1.14
1.75
1.87
3.19
.79
1.66
1.68
2.17

.81
1.61
1.52
2.42
IQB-7.5 means IQB with 7.5% weight reduction prior to blanching.
IQB-0 means IQB without predrying.
20 sec means heat only stage of IQB.
Deep bed means deep bed steam blanching.
                               65

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Table A4.  CHARACTERISTICS OF EFFLUENTS GENERATED DURING CORN BLANCHING
a
Treatment
number
1C
2C
3C
4C
5C
6C
7C
8C
9C
IOC
11C
12C
Pipe
Pipe
Pipe
Averages
IQB-7.5
IQB-0
20 Sec
Deep bed
Pipe
BODr
(ppm)
10400
14000
12500
16600
24900
22700
28300
37800
13800
26500
31000
26800
3000
6500
11000

16400
21000
23900
27000
6800
COD
(ppm)
—
—
--
—
29900
32400
33400
51900
23300
34200
34500
30700
—
--
—

26600
33300
34000
41300
—
Total
solids
(%)
1.94
2.71
2.23
3.10
3.38
3.50
3.48
5.09
2.13
3.68
3.72
3.69
.455
.884
1.61

2.48
3.30
3.14
3.96
.983
Total
phosphorus
(ppm)
104
159
135
170
105
132
142
189
87
172
169
154
30
40
72

99
154
149
171
47
Total
organic
nitrogen
(ppm)
177
296
231
260
211
255
256
322
196
368
398
318
68
100
208

195
306
295
300
125
                                  66

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               Table A4 (continued).   CHARACTERISTICS  OF
               EFFLUENTS  GENERATED DURING CORN BLANCHING
Volatile
Treatment solids
number (ppm)
1C 18300
2C 25600
3C 20900
4C 29100
5C 32400
6C 33500
7C 33300
8C 48900
9C 20500
IOC 35300
11C 35900
12C 34200
Pipe 3970
Pipe 8250
Pipe 15200
Averages
IQB-7.5 23700
IQB-0 31500
20 Sec 30000
Deep bed 37400
Pipe 9140
Suspended
volatile
solids
(ppm)
1240
1700
3010
712
1780
6390
8660
2460
1360
13400
4710
2060
215
460
1120

1460
7170
5460
1750
600
Suspended
solids
(%)
.136
.179
.307
.076
.187
.639
.880
.247
.136
(1.344)C
.471
.206
.022
.047
.112

.153
.409°
.553
.176
.060
Soluble
phosphorus
(ppm)
50
89
86
98
101
106
114
151
17
38
37
24
15
30
18

56
78
79
91
21
Nitrogen
NH3
Cppm)
7
5
4
8
22
13
13
25
11
14
13
16
2
7
7

13
11
10
17
5
NO b
NO^
(ppm)



















N02d
(ppm)
--
—
—
—
.02
.03
.03
Trace
Inter
Inter
Inter
Inter
—
.10
Inter

.02
.03
.03
Trace
.10
pH
6.5
6.4
6.8
6.8
7.0
7.0
6.9
6.9
7.0
6.9
7.0
7.2
7.5
7.9
6.9

6.8
6.8
6.9
7.0
7.4
See footnote and treatment number on Table A3.
Interference on all Npg-N determinations.
The 1.344 value was not used in the average since it was higher than
corresponding values by factor of 10.

No value means too small to be measured.
Inter means interference.
                               67

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    Table A5.  INDIVIDUAL BLANCHING TRIALS  FOR LIMA BEANS
a
Blanching
treatment
IQB-5.0
IQB-O
20 Sec
Deep bed
IQB-O
20 Sec
Deep bed
Averages
IQB-5
IQB-O
20 Sec
Deep bed
treatment
number
1LB
2LB
3LB
4LB
5LB
6LB
7LB





Belt loading
Heat
Hcg/m2)
4.83
5.76
6.10
15.32
4.39
5.12
14.35

4.83
5.08
5.61
14.84
Hold
(kg/m2)
61.78
73.15
—
—
55.79
—
—

61.78
64.46
—
—
Effluent
generation
(l./case)
.406
.879
.750
1.00
1.22
.860
1.91

.406
1.05
.807
1.46
Product
yield
(%)
97.5
95.6
97.5
94.1
91.3
95.9
83.4

97.5
93.4
96.7
88.7
Solids lost
as product
(%)
.24
.63
.34
.84
1.10
.75
1.93

.24
.86
.54
1.38
IQB-5.0 means IQB with a 5.0% weight reduction prior to blanching.
IQB-O means IQB without predrying.
20 sec means heat only stage of IQB.
Deep bed means deep bed steam blanching.
                              68

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Table A6.  CHARACTERISTICS OF EFFLUENTS GENERATED
           DURING LIMA BEAN BLANCHING
o
Treatment
number
1LB
2LB
3LB
4LB
5LB
6LB
7LB
Pipe
Pipe
Pipe
Pipe
Averages
IQB-5.0
IQB-O
20 Sec
Deep bed
Pipe
BOD5
(ppm)
5220
6170
5810
12800
13700
29900
16300
1200
770
400
400

5220
9930
17800
14500
693
COD
(ppm)
7790
11900
6750
13800
17600
12800
21200
—
—
—
—

7790
14800
9780
17500
—
Total
solids
(°/\
\lo)
1.20
1.48
0.91
1.77
1.96
1.80
2.42
.20
- .13
.10
.10

1.20
1.72
1.36
2.10
.13
Total
phosphorus
(ppm)
53
71
47
100
160
146
225
38
8
6
6

53
116
97
163
15
Total
organic
nitrogen
(ppm)
341
557
318
495
864
560
879
42
26
27
28

341
711
439
687
31
                   69

-------
           Table A6 (continued).  CHARACTERISTICS OF
           EFFLUENTS GENERATED DURING LIMA BEAN BLANCHING
Volatile
Treatment solids
number (ppm)
1LB 9830
2LB 12300
3LB 7470
4LB 14500
5LB 14100
6LB 15200
7LB 19600
Pipe 1390
Pipe 850
Pipe 625
Pipe 660
Averages
IQB-5.0 9830
IQB-0 13200
20 Sec 11400
Deep bed 17000
Pipe 881
Suspended
volatile
solids
(ppm)
606
2320
1370
2250
2520
1660
2650
125
65
25
30

606
2420
1520
2450
61
Suspended
solids
(%)
.060
.240
.154
.228
.263
.182
.282
.014
.010
.004
.005

.060
.252
.168
.255
.008
Soluble
phosphorus
(ppm)
35
40
27
43
9
8
10
13
2
1
1

35
25
18
26
4
Nitrogen
NH3
(ppm)
6
9
7
16
20
17
13
2
1
2
1

6
15
12
14
2
NO &
NOj
(ppm)
4.5
4.1
3.2
3.1
Inter
Inter
Inter
2.7
2.5
Inter
Inter

4.5
4.1
3.2
3.1
2.6
b
N02
(ppm)
.07
.05
.05
.02
Inter
Inter
Inter
.02
.02
Inter
Inter

.07
.05
.05
.02
.02
PH
6.8
6.7
6.8
6.4
6.5
6.6
6.5
8.5
8.6
7.9
7.6

6.8
6.6
6.7
6.5
8.2
See footnote and treatment number on Table A5.
Pipe refers to pipe blanching.
Inter means interference.
                              70

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   Table A7.  INDIVIDUAL BLANCHING TRIALS FOR GREEN BEANS
Blanching
treatment
IQB-0
Deep bed
IQB-O.
IQB-C
Deep bed
Deep bed
Averages
IQB-0
Deep bed
Preatment
number
1GB
2GB
3GB
4GB
5GB
6GB



Belt loading
Heat
(kg/m2
6.78
7.42
4.39
5.12
6.73
6.88

5.42
7.03
Hold
(kg/m2)
86.72
—
55.78
65.05
—
—

69.20
—
Effluent
generation
(l./case)
1«30
1.10
.841
.883
.618
.603

1.01
.773
Product
yield
a)
90.0
92.8
96.3
95.6
99.4
99.7

94.0
97.3
Solids lost
as product
(%)
w w
2.09
1.88
.45
.34
.23

1.16
.89
IQB-0 means IQB without predrying.
Deep bed means deep bed steam blanching.
                            71

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           Table A8.   CHARACTERISTICS  OF EFFLUENTS  GENERATED

                      DURING GREEN BEAN BLANCHING
a
Treatment
number
1GB
2GB
3GB
4GB
5GB
6GB
Averages
IQB-0
Deep bed
BOD
(ppm}
5890
9320
10100
2230
2560
1790

6070
4560
COD
(ppm)
2910
6530
--
--
--
__

2910
6530
Total
solids
(%)
--
1.26
1.43
.324
.341
.235

.877
.612
Total
phosphorus
(ppm)
53
72
82
21
24
17

52
38
Total
organic
nitrogen
(ppm)
149
235
270
156
64
53

192
117
a
Treatment
number
1GB
2GB
3GB
4GB
5GB
6GB
Averages
IQB-0
Deep bed
Volatile
solids
(ppm)
—
10700
12000
2700
2850
1980

7350
5190
Suspended
volatile
solids
(ppm)
—
191
1010
261
99
119

636
136
Suspended
solids
(%)
—
.026
.123
.036
.013
.016

.080
.018
Soluble
phosphorus
(ppm)
36
42
4
11
1
1

17
15
Nitrogenb
NH3
(ppm)
11
5
27
2
2
2

14
3
NO
NO;;
(ppm)









N02
(ppm)









PH
7.9
6.5
5.3
5.2
5.1
5.5

6.1
5.7
See footnote and treatment number on Table A7.

        and N0_ were not determined.
              £
                                 72

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      Table A9.  INDIVIDUAL BLANCHING TRIALS FOR POTATOES
o
Blanching Treatment
treatment number
IQB-6.9
IQB-O
Deep bed
IQB-O
IQB-O
Averages
IQB-6.9
IQB-O
Deep bed
1POT
2 POT
3 POT
4 POT
5 POT




Belt loading
Heat
(kg /TCI)
3.56
5.76
11.76
5.76
5.08

3.56
5.51
11.76
Hold
(kg An2)
17.03
18.30
—
18.30
16.10

17.03
17.57
—
Effluent
generation
(l./case)
.754
1.31
1.25
1.40
.868

.754
1.20
1.25
Product
yield
a)
93.1
93.1
93.8
92.2
95.0

93.1
93.4
93.8
Solids lost
as product
(I)
.43
.60
.78
.60
.61

.43
.60
.78
IQB-6.9 means IQB with a 6.9% weight reduction prior to blanching,
IQB-O means IQB with no predrying.
Deep bed means deep bed steam blanching.
                                 73

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           Table A10.  CHARACTERISTICS OF EFFLUENTS GENERATED
                       DURING POTATO BLANCHING
a
Treatment
number
1POT
2 POT
3 POT
4POT
SPOT
Averages
IQB-6.9
IQB-0
Deep bed
BOD_
(ppm}
5000
4030
3780
4260
4720

5000
4340
3780
COD
(ppm)
6340
4500
3640
4370
5790

6340
4890 -
3640
Total
solids
a)
0.930
0.746
1.01
0.707
0.856

0.930
0.770
1.01
Total
phosphorus
(ppm)
85
66
102
65
78

85
70
102
Total
organic
nitrogen
(ppm)
302
264
397
249
329

302
281
397
Treatment
number
1POT
2 POT
3 POT
4 POT
SPOT
Averages
IQB-6.9
IQB-0
Deep bed
Volatile
solids
(ppm)
7440
6010
8000
5720
5550

7440
5760
8000
Suspended
volatile
solids
(ppm)
775
1080
1490
171
1270

775
842
1490
Suspended
solids
(7c)
.081
.114
.156
.020
.133

.081
.089
.156
Soluble
phosphorus
(ppm)
48
46
57
41
52

48
47
57
Nitrogen
NH3
(ppm)
24
20
36
23
25

24
23
36
NO
NOf
(ppm)
12
11
16
10
13

12
11
16
N02
(ppm)
.29
.05
.09
.09
.05

.29
.06
.09
PH
6.9
7.1
6.9
7.0
6.9

6.9
7.0
6.9
See footnote and treatment number on Table A9,
                                74

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           Table All.  INDIVIDUAL BLANCHING TRIALS FOR BEETS
»a
Blanching
treatment
IQB-5.6
IQB-0
Deep bed
IQB-0
IQB-0
Averages
IQB-5.6
IQB-0
Deep bed
]
Treatment
number (
IB
2B
3B
4B
5B




ielt loading
Hea^
kg/m )
6.49
7.66
L6.40
6.88
6.44

6.49
7.00
16.40
Hold
(kg/m2)
27.62
32.55
—
29.28
27.47

27.62
29.77
--
Effluent
generation
(l./case)
1.48
1.84
1.68
1.61
1.74

1.48
1.73
1.68
/
Product
yield
(°l\
\'°)
86.3
87.8
89.4
90.0
88.8

86.3
88.9
89.4
Solids lost
as product
(%)
5.21
4.01
5.26
3.76
4.29

5.21
4.02
5.26
IQB-5.6 means IQB with a 5.6% weight reduction prior to blanching.
IQB-0 means IQB with no predrying.
Deep bed means deep bed steam blanching.
                                 75

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Table A12.  CHARACTERISTICS OF EFFLUENTS GENERATED DURING BEET BLANCHING
a
Treatment
number
IB
2B
3B
4B
5B
Averages
IQB-5.6
IQB-O
Deep bed
BOD5
(ppm)
29400
16700
21500
28600
19200

29400
21500
21500
COD
(ppm)
29700
22600
25700
19200
25000

29700
22300
25700
Total
solids
(%)
3.89
2.36
3.34
2.46
2.64

3.89
2.49
3.34
Total
phosphorus
(ppm)
145
91
136
98
95

145
95
136
Total
organic
nitrogen
(ppm)
556
349
492
378
379

556
369
492
Treatment
number
IB
2B
3B
4B
5B
Averages
IQB-5.6
IQB-O
Deep bed
Volatile
solids
(ppm)
33600
20800
29000
21500
23100

33600
21800
29000
Suspended
volatile
solids
(ppm)
378
156
214
224
170

378
183
214
Suspended
solids
(%)
.056
.017
.022
.027
.021

.056
.022
.022
Soluble
phosphorus^
(ppm)









Nitroeen
NH3
(ppm)
105
60
108
61
64

105
62
108
NO b
NOJ2
(ppm)









N02b
(ppm)









PH
6.6
6.6
6.5
6.7
6.6

6.6
6.6
6.5
  See footnote and treatment number on Table All.
  Interference in tests for soluble phosphorus, NO--N and NO -N.

                                  76

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             Table A13.  INDIVIDUAL BLANCHING TRIALS FOR CARROTS
Blanching Treatment
treatment number (
IQB-0 1CAR
Deep bed 2CAR
IQB-0 SCAR
IQB-0 4CAR
Averages
IQB-0
Deep bed
Belt loading
Hea|
kg An )
9.86
16.01
9.86
8.64

9.45
16.01
Hold
(kg/m2)
41.82
—
41.82
36.60

40.06
—
Effluent
generation
(l./case)
1.30
1.49
1.27
1.27

1.28
1.49
Product
yield
a)
91.6
88.4
91.9
91.9

91.8
88.4
Solids lost
as product
C7o)
1.54
2.77
1.86
2.39

1.93
2.77
a
  IQB-0 means IQB without predrying.
  Deep bed means deep bed steam blanching.
                                   77

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Table A14.   CHARACTERISTICS OF  EFFLUENTS GENERATED DURING CARROT BLANCHING
a
Treatment
number
1CAR
2CAR
3CAR
4CAR
Averages
IQB-0
Deep bed
BOD
(ppm}
8340
11700
10200
12500

10300
11700
COD
(ppm)
10600
12100
10700
16400

12600
12100
Total
solids
(7=)
1.02
1.56
1.25
1.61

1.29
1.56
Total
phosphorus
(ppm)
66
100
81
106

84
100
Total
organic
nitrogen
(ppm)
439
623
512
649

533
623
Treatment
number
1CAR
2 CAR
3CAR
4CAR
Averages
IQB-0
Deep bed
Volatile
solids
(ppm)
8520
12700
10600
12500

10600
12700
Suspended
volatile
solids
(ppm)
170
436
283
835

429
436
Suspended
solids
(%)
.034
.044
.029
.097

.053
.044
Soluble
phosphorus
(ppm)
59
100
80
97

79
100
Nitrogen
NH3
(ppm)
39
56
40
48

42
56
NO
NO£
(ppm)
30
44
38
49

39
44
N02
(ppm)
25
36
33
29

29
36
PH
5.1
5.8
5.9
5.5

5.5
5.8
  See  footnote and treatment  number on  Table A14.
                                      78
                                               *U.S. GOVERNMENT PRINTING OFFICE: 1974 546-318/377  1-3

-------
 SELECTED WATER
 RESOURCES ABSTRACTS
 INPUT TRANSACTION FORM
                                                                     3. Accession No.
                      W
  4. Title
     WASTEWATER ABATEMENT IN CANNING VEGETABLES BY IQB
     BLANCHING
  7. Authorts)
    Lund, Daryl B.
    University of Wisconsin
    Department of Food Science
    Madison, Wisconsin   53706
                       5- R^pew tww
                                                                      8, PerfortttJuc Organization
                      10. Project No.
                         ^
                      11. Contract/Giant No.
                         S-801484

                     • 1L Type -of Report and .
                         f'caod
 1S. Supplementary Notes

    Environmental Protection Agency Report Number:   EPA-660/2-74-006, April 1974
 16. Abstract

    A study on the efficacy of a new blanching system,  Individual Quick Blanch (IQB),
    as applied to vegetables prior to canning was conducted.   Peas, corn, lima beans,
    green beans, potatoes,  carrots and beets were adequately blanched by IQB.   Compared
    to deep bed steam blanching or pipe blanching,  IQB  generally resulted in  a signifi-
    cant reduction in effluent.  Slight drying of the vegetables before IQB reduced
    effluent even more; however, product quality was adversely affected In most cases.
    It was demonstrated that the IQB process can significantly reduce effluent volume
    and BOD generation in the blanching operation while adequately fulfilling the
    objectives of blanching.  Recommendations for commercial development of IQB are
    given.                                                           '
 17a. Descriptors

    Blanching, Individual Quick Blanching, Pollution Abatement, Water Pollution,
    Cannery Wastes, Vegetable Processing Wastes
 17b. identifiers
 I7c.  COWRR Field & Group-
    Availability
        Send To:

        WATER RESOURCE* SCIENTIFIC INFORMATION CENTER
        UA DEPARTMENT OF THE INTERIOR
        WASHINGTON. D.C. M240
 Abstractor
           Daryl B. Lund
University  of Wisconsin-Madison
WRSlC 102 (REV. JUNE 1971]
                                                                                   G P O

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