Group Title: Citrus Station mimeo series - Florida Citrus Commission ; 63-3
Title: Improved methods for determining pounds-solids in oranges for processing
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 Material Information
Title: Improved methods for determining pounds-solids in oranges for processing
Series Title: Citrus Station mimeo series
Physical Description: 4, 2 leaves : ill. ; 28 cm.
Language: English
Creator: Blair, James G
Citrus Experiment Station (Lake Alfred, Fla.)
Florida Citrus Commission
Publisher: Florida Citrus Experiment Station :
Florida Citrus Commission
Place of Publication: Lake Alfred FL
Publication Date: 1962
Subject: Oranges -- Processing -- Florida   ( lcsh )
Oranges -- Quality -- Florida   ( lcsh )
Genre: government publication (state, provincial, terriorial, dependent)   ( marcgt )
non-fiction   ( marcgt )
Summary: Includes a panel discussion on high-density frozen concentrated orange juice and a list of publications concerning high-density frozen concentrated citrus juices.
Statement of Responsibility: James G. Blair.
General Note: Caption title.
General Note: "October 2, 1962."
Funding: Citrus Station mimeo report ;
 Record Information
Bibliographic ID: UF00072416
Volume ID: VID00001
Source Institution: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: oclc - 75958965

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Citrus Station Mimeo Series 63-3
October 2, 1962

Improved Methods for Determining Pounds-Solids in Oranges for Processing

James G. Blair
Florida Citrus Commission
Lake Alfred, Florida

For the benefit of those who may not know the background for this project,
it is deemed advisable to briefly mention what has taken place. In February,
1961, the Florida Citrus Commission met to consider the problems connected with
sampling and testing procedures for oranges at processing plants. As a result
of this meeting, a survey team was formed to define as precisely as possible
the problems associated with sampling and testing oranges for processing to
determine juice content, soluble solids, acid and pounds-solids per 90 lb. box
and to develop a suggested plan for further research, seeking solutions to these
problems. The report of the survey team was published on March 15, 1961, and a
copy was sent to each of the processing plants. This report recommended that an
engineer should be responsible for this project so during the early part of this
year the Citrus Commission employed me for this position. It was thought that
it would take three to five years to develop a workable program, but the
installation of any equipment in commercial plants would be scheduled at the
discretion of the individual processors.

There are many uncontrollable variations in the methods necessary to ob-
tain a satisfactory pounds-solids determination; so for the purpose of this
discussion, all the variations resulting from the growing and harvesting of the
fruit will be overlooked. Starting at the processing plant's receiving scale,
a loaded truck of fruit is weighed and this weight is automatically stamped on
the driver's field ticket which has been placed in a slot of the scale printer.
The scale man keeps a log of the name of the supplier and driver, truck or
trailer number, grove, weight and other information. This system is used by
most plants and is quite satisfactory although additional automation would be
desirable. For example, the load identity and gross weight, in addition to
being printed on the driver's ticket, could be placed into a memory system for
use when the pounds-solids content is desired. A relatively simple computer
could perform this function and print out the required information.

For simplicity, the project has been divided into three categories --
sample selection, extraction and measurement of juice content, and analysis
of juice for Brix and acid.

Selection of Sample

Normal precautions are necessary on the control of the load between the
scale house and the unloading point for the advent of automation is not going
to preclude the possibility of someone trying to beat the system. After the

Florida Citrus Commission and
Florida Citrus Experiment Station,
Lake Alfred, Florida.
10/2/62 JGB

load has been spotted and unloading commences, the currently used principle of
selecting the sample is quite similar in most plants in that some sort of
mechanical means is provided in the unloading conveyor to theoretically select
a random sample. There still is a wide divergence from plant to plant in the
point of selection and the method used to control the size of the sample. The
plants that do not select after grading realize this weakness but in most cases
have not modified their system due to the extensive changes required. The
method of controlling the size of the sample is complex because of a number of
variables such as load size, different unloading positions, rate of unloading,
effectiveness of the sampling device and others. Much improvement is needed in
this area to obtain better control of the over-all size of the sample. Infor-
mation extracted from "Cannery Work Sheets" indicating the deviations between
the load size and the sample size are shown in Figures 1 and 2. After looking
at these figures it is hard to imagine that this represents a considerable
improvement over only a few years ago. George F. Westbrook and his department
of the Fruit and Vegetable Inspection Division, Florida Department of Agricul-
ture, have been working hard on this problem and with the cooperation of all the
canners, they have made considerable progress.

A simple method to check the effectiveness of the sampling devices used at
the plants is to count and weigh as much of the fruit as possible while it is
being unloaded from the truck. This gives an average weight of the fruit in
the load. Then, by counting and weighing the State test sample from the same
load, the amount of variation can be determined.

The pilot fruit receiving system now installed at the Citrus Experiment
Station will be used to develop better methods to select random samples. It
will be possible to control most of the variables in the unloading process and
measure their effects on the sample obtained. The samples and/or the loads
can be run through the Station packinghouse for sizing and counting and, in
this manner, the accuracy of the sampling technique can be determined.

Another method used to check the sampling, as well as the juice analysis,
done at the plants is to run a large (100-200 boxes) load of fruit through the
packinghouse where it can be sized, counted and a double sample selected. These
samples are then counted and weighed to determine an average weight. The test
load and one of the samples are then sent to a processing plant. While unload-
ing, a double sample also is obtained at the plant and one is counted and weighed
to determine the average weight. This sample, together with the one brought from
the Station, is analyzed for juice content, Brix and acid. The remaining sample
obtained at the plant is returned to the Station where it is sized, counted and
weighed; then it and the original sample taken at the Station are analyzed for
juice content, Brix and acid. The results of these cross-checks are analyzed for
variations, trends or other information that might be helpful in improving the
over-all operation. Other methods are being considered, such as pre-selecting
an oversized sample while simultaneously evaluating the load for individual fruit
size, variety, color and other characteristics. The load analysis would be fed
to a regulating device that would measure out the exact representative sample
from that pre-selected.

Florida Citrus Commission and
Florida Citrus Experiment Station,
Lake Alfred, Florida,
10/2/62 JGB



50- PLANT 8- JUNE 2 -
50 0 0
*- PLANT C-APRIL 12 x-

40 *-


475 500


Figure 1

Plant Comparison



Figure 2

Detail Data for Plant

475 500 525

NOTE: Mean Sample Wt./Box = ESample Wts.
'No. of Boxes

Theoretical Ideal Sample Wt. = Mean Sample Wt./Box x No. of Boxes






** *
** I

Extraction and Measurement of Juice Content

To reduce to a minimum the variations normally encountered in the juice
extraction fruit samples were prepared as near alike as it was physically
possible to make them. -These samples were made up after grading, sizing,
counting and weighing; each sample contained the same number of each size
orange and the average weights of like samples were held to a very close toler-
ance of + .015 lb. Since the size of the individual fruit has an effect on all
the elements of the analysis, some tests were made last season on the effect of
size; the results are shown in Figure 3. The Brown extractor used for these
tests was set identical to those used in the State test stations. For compari-
son results of tests made by Sites and Deszyck were reported (Food Technol., 9,
363, 1955. See Table 6) and are shown in Figure 4. The basic difference in
the methods used was that Sites and Deszyck tested samples of each size while
the tests made last season were on samples of varying average weights. Despite
this basic difference both sets of results are quite similar. The acid curve
from the recent tests was not as uniform as could be desired but more accurate
means of determination should improve this, as well as the other data.

There are inherent differences among extracting machines of like manufacture,
so it is easy to see how there could be wider differences in juice content among
machines of different manufacture. The effect of these differences is not con-
stant and does not always occur in all plants at the same time; so when the
statewide results are compared, there naturally are some differences. An
analysis of these differences, as made by the Inspection Division, shows the
industry yield average on single-strength orange juice production at approxi-
mately 99% and the concentrate production yield at approximately 104%. These
figures are significant in that the difference represents just about what would
be expected from pulp washing during processing of concentrate, so on the
average it seems there was reasonable control of the test machines.

The existing extractors are being constantly improved and the development
of new machines is being encouraged. In fact, it is planned to test two new
extractors this coming season; one is being manufactured by Brown Machinery
Company strictly for State test work, while the other is being developed by
Anderson Brothers for commercial application. There is also an electronic
machine being built for Florida Citrus Mutual by Mechtron, Inc., which is
supposed to determine the juice content, Brix and acid of the juice in an
orange by measuring the electrical conductance. At least one of these machines
will be field tested this season.

Analysis of Juice

One of the biggest problems in analyzing the juice is the possibility of
human errors. This starts with the adjustment of the sample for even or one-
half pound weights. The feeding of the extractor and the manipulation of the

Florida Citrus Commission and
Florida Citrus Experiment Station,
Lake Alfred, Florida.
10/2/62 JGB


.020 SCREEN /101 AIR

.30 .40 .50 .60 .70

Figure 3. Analysis vs Average Wt. Samples

DATA 1952

288 216 176 150

Figure U. Analysis vs Sized Samples








equipment used for determining Brix and acid are subject to varying degrees of
error. The inspector also is relied upon to detect errors due to equipment
malfunctions and, therefore, results are based on the degree of alert obser-
vation. These human errors can be classified into various categories, such as
manual and judgment. A check of errors in arithmetic and transcription showed
that they are only about 0.3%. Of course, this represents only the frequency
of the errors and not the degree. The errors of judgment are not so easily
checked and, therefore, are the ones that should first be eliminated. With
this thought in mind, several equipment manufacturers are working on automatic
Brix and acid instruments that will print the data in the same way as the scale
printer records the weight. It should be possible to make some comprehensive
tests on this equipment during the 1962-63 season and, based on the results of
these tests, consideration will be given to the possibility of automating the
entire operation through the use of a computer with a print-out mechanism.


Selection of sample. A typical vertical fruit elevator with sampling
devices has been constructed at the Station for the purpose of determining the
best method to select a random sample. Tests will be made with this equipment
throughout the coming season and the sampling devices will be spot checked at
plants for comparative results. Since most industries use some sort of samp-
ling technique in their process, a study of all known methods is being made for
ideas that may be of assistance in the developing of a satisfactory procedure
for the citrus industry.

Extraction and measurement of juice content. Extractors have been obtained
similar to those used for State test purposes and have been and will continue to
be used for a series of comparative tests using carefully selected samples. Two
new extractors should be available for testing this season to determine whether
they would be satisfactory for State test machines. Also, our investigation for
better methods of determining juice content is continuing.

Analysis of juice. Plans include the testing of machines to automatically
determine Brix and acid of citrus juices. Work is also being done on a system
that will measure the load weight, sample weight, juice weight, Brix and acid
and then compute both the Brix/acid ratio and the pounds of solids and finally
write out such data on a ticket. The ramifications on the further use of this
information as stored is unlimited.

Florida Citrus Commission and
Florida Citrus Experiment Station,
Lake Alfred, Florida.
10/2/62 JGB


High-Density Frozen Concentrated Orange Juice

Moderator: H. E. Apple, Manager of Production, Birdseye Division, General
Foods Corporation, Winter Haven, Florida.

Potentialities of High-Density Frozen Orange Concentrate and Some
Management Problems. A. H. Reppard, Jr., Vice-President in Charge
of Operations, Pasco Packing Company, Dade City, Florida.

Equipment for Production of High-Density Frozen Orange Concentrate.
J. M. Fiske, Fiske-Gay Associates, Inc., Consultant Engineers,
Orlando and Lakeland, Florida.

Quality of High-Density Frozen Orange Concentrate and Its Control.
Charles H. Brokaw, Director of Quality Control, Minute Maid
Company, A Division of the Coca-Cola Company, Orlando, Florida.

Consumer Surveys and Marketing Aspects of High-Density Frozen Orange
Concentrate. William E. Black, Director of Marketing Research,
Florida Citrus Commission, Lakeland, Florida.

The subject of this panel discussion is believed to be both timely and of
importance to the Florida citrus industry. Also, it is hoped that the
information presented by the panel members together with subsequent discussion
by persons attending this meeting will provide, to some extent, assistance to
those persons, commercial companies, and other organizations, who eventually
will have to make the decisions concerning the production, quality, and sale
of high-density frozen orange concentrate.

The panel members were not requested to submit any data or information for
mimeographing and, therefore, no reports are available for distribution. A
list of some publications follows in which information may be found concerning
high-density frozen concentrated citrus juices.

The assistance of Mr. H. E. Apple in moderating the panel discussion on
"High-Density Frozen Concentrated Orange Juice" is appreciated. Thanks
are extended to him, Mr. A. H. Reppard, Jr., Mr. J. M. Fiske, Mr. Charles
H. Brokaw, and Dr. William E. Black for the time and effort expended by
them in participating on this panel.

Florida Citrus Experiment Station
and Florida Citrus Commission,
Lake Alfred, Florida.
10/2/62 FWW

High-Density Frozen Concentrated Citrus Juices Publications

The following list of publications contain some information on high-density
citrus concentrates. This list contains all of the references that are known to
us at this time; however, some other publications also may have been published.

Barreto, A., Jr. 1953. Studies on the rate of growth of potential spoil-
age bacteria in orange juice. Master of Science Thesis. University of Florida,
Gainesville, Florida.

Bissett, Owen W., M. K. Veldhui; and N. B. Rushing. 1953. Effect of heat
treatment temperature on the storage life of Valencia orange concentrate. Food
Technol. 7: 258-260.

Bissett, 0. W., M. K. Veldhuis, R. B. Guyer, and W. M. Miller. 1955. The
production and stability of "Hi-Brix" frozen orange concentrate (58.5 Brix).
Citrus Processing Conference. U. S. Citrus Products Station, Winter Haven,
Florida. October 11.

Bissett, 0. W., M. K. Veldhuis, R. B. Guyer, and W. M. Miller. 1957.
Stability of frozen concentrated orange juice. III. The effect of heat treat-
ment in the production of high-Brix frozen concentrate. Food Technol., 11:

Cotton, R. H., W. R. Roy, C. H. Brokaw, 0. R. McDuff, and A, L. Schroeder,
1947. Storage studies on frozen citrus concentrates. Proc. Florida State
Hort. Soc. 60: 39-50.

Dietz, J. H. and F. W. Wenzel. 1952. Changes in pectic substances in
Valencia orange juice during concentration. Proc. Florida State Hort. Soc.
65: 234-237.

DuBois, C, W. and D. I. Murdock. 1955. The effect of concentration on
quality of frozen orange juice with particular reference to 58.50 and 420 Brix
products. Chemical and physiological aspects. Food Technol. 9: 60-63.

Huggart, R. L. 1952. Effect of concentration on clarification in con-
centrated citrus juices. Proc. Florida State Hort. Soc. 65: 237-242.

McColloch, R. J., R. G. Rice, Bruno Gentilli, and E. A. Beavens. 1956.
Cloud stability of frozen superconcentrated citrus juices. Food Technol. 10:

Murdock, D. I. and C. W. DuBois. 1955. Effect of concentration on quality
of frozen orange juice with particular reference to 58.50 and h2 Brix products.
II. Bacteriological aspects. Food Technol. 9: 64-67.

Florida Citrus Experiment Station
and Florida Citrus Commission,
Lake Alfred, Florida.
10/2/62 FWW


Patrick, Roger and R. L. Huggart. 1955. Characteristics of six-fold frozen
concentrated orange juice. Proc. Florida State Hort. Soc. 68: 170-174.

Rice, R. G., G. J. Keller, R. J. McColloch, and E. A. Beavens. 1954. Fruit
concentrates. Flavor-fortified high-density frozen citrus concentrates. J.
Agr. Food Chem. 2: 196-198.

Rouse, A. H. 1949. Gel formation in frozen citrus concentrates thawed and
stored at 40F. Proc. Florida State Hort. Soc. 62: 170-173.

Rouse, A. H., C. D. Atkins, and E. L. Moore. 1960. Effect of pectinester-
ase on the stability of frozen concentrated orange juice. Proc. Florida State
Hort. Soc. 73: 271-276.

Rouse, A. H., C. D. Atkins, and E. L. Moore. 1961. Recent studies of the
effect of pectinesterase on the stability of frozen concentrated orange juices.
Proc. Florida State Hort. Soc. 74: 223-229.

Rushing, N. B., R. Patrick, and M. K. Veldhuis. 1953. Effect of concen-
tration of orange juice and temperature of storage on growth and survival of
microorganisms. Proc. Florida State Hort. Soc. 66: 281-286.

Rushing, N. B., M. K. Veldhuis, and V. J. Senn. 1955. Growth rates of
Lactobacillus and Leuconostoc species in orange concentrates. Citrus Processing
Conference. U. S. Citrus Products Station, Winter Haven, Florida. October 11.

Sinclair, Walton B. The Orange Its Biochemistry and Physiology. 1961.
Order book from Agricultural Publications, 207 University Hall, University of
California, Berkeley 4, California.

Tressler, Donald K. and Maynard A. Joslyn. Fruit and Vegetable Juice
Processing Technology. 1961. The Avi Publishing Company, Inc., Westport,

Wenzel, F. W., E. L. Moore, A. H. Rouse, and C. D. Atkins. 1951. Gelation
and clarification in concentrated citrus juices. I. Introduction and present
status. Food Technol. 5: 454-457.

Papers for Publication in the Future

Ezell, G. H., R. W. Barron, R. W. Olsen, and F. W. Wenzel. Factors affect-
ing the viscosity of orange concentrate. Paper presented at the 22nd Annual
Meeting of the Institute of Food Technologists, Miami Beach, Florida, June, 1962;
paper submitted for publication in "Food Technology".

Kew, T. J. Cloud and flavor stability in relation to density of frozen con-
centrated orange juice. Paper to be presented at annual meeting of the Florida
State Horticultural Society in Miami Beach, Florida, October, 1962.

Veldhuis, M. K. and T. J. Kew. Effect of time and temperature of storage on
the quality of frozen concentrated citrus juices. Paper presented at annual meet-
ing of American Society of Heating, Refrigerating, and Air-Conditioning Engineers,
Inc., at Miami Beach, Florida, September, 1962; paper submitted for publication
in "Refrigerating Engineering".

Florida Citrus Experiment Station
LU -.. Lake 'TT'Ra. Florida. 10/2/62 F

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