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TWENTY- EIGHTH ANNUAL CITRUS

PROCESSORS' MEETING

OCTOBER 6, 1977

AGRICULTURAL RESEARCH & EDUCATION CENTER
Lake Alfred, Florida

and

STATE OF FLORIDA DEPARTMENT OF CITRUS

Lakeland, Florida
and

COOPERATIVE EXTENSION SERVICE
Institute of Food and Agricultural Sciences
University of Florida, Gainesville

OCT14 1 19377

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*I
CS-1977-2
300-10/6/77
Lake Alfred, Florida

FOREWORD

On behalf of the Institute of Food and Agricultural Sciences, I
extend to you a cordial welcome to the 28th Annual Citrus Processors'
Meeting.

Our program this year deals primarily witn the familiar but always
important issue of product quality maintenance. We may never reach the
ultimate exploitation of this aspect of our business, but we need to
keep quality uppermost among our objectives.

Other aspects of the program touch on energy conservation, an in-
creasingly important concern, and marketing considerations. Altogether,
we try to keep our program closely related to the real problems the pro-
cessing industry deals with, and hope everyone attending will find here
something specifically useful.

Herman J. Reitz, Director
Agricultural Research and Education
Center, Lake Alfred

The Florida Department of Citrus staff is delighted to see all of
you in attendance at this 28th Annual Citrus Processors' Meeting spon-
sored jointly by the University of Florida and the Florida Department
of Citrus.

The program this year will include many important topics. I would
particularly like to call your attention to the progress report on opti-
mizing energy uses in the plant. This timely study was initiated at
your request and is to be expanded in future years. Other current sub-
jects include measurement of grapefruit juice color, analysis of trace
metals in juices of different geographic locations and effect of freeze
on quality, yield and demand.

The number of papers to be heard act against a long question and
answer period. We encourage you to carry your individual questions to
the speakers during the OJ break, the lunh hour or after the meeting.

John A. Attaway
Scientific Research Director
Florida Department of Citrus

PROGRAM

University of Florida
Agricultural Research & Education Center
Post Office Box 1088
Lake Alfred, Florida 33850

Thursday, October 6, 1977
9:00 AM Registration
9:35 AM Welcome
Dr. H. J. Reitz, Director
Agricultural Research and Education Center,
Lake Alfred, Florida
9:40 AM Introductory remarks
Dr. J. A. Attaway
Director of Scientific Research
Florida Department of Citrus

MORNING PROGRAM 9:45-12:00

Chairman Mr. Robert Williard
Citrus World, Inc.
Interpretation of grapefruit juice color measurements and
product color standardization
R. L. Huggart and D. R. Petrus
Florida Department of Citrus
Development of a commercial method for the recovery of
natural color pigment granules from citrus juices
R. W. Barron
Florida Department of Citrus
A review of some process and formula patents obtained by
the Florida Department of Citrus
M. D. Maraulja
Florida Department of Citrus
Differences in some physical and chemical characteristics
between orange juice and water extract of orange juice pulp
S. V. Ting and R. D. Carter
Florida Department of Citrus

OJ BREAK

Comparative metal contents of Florida and Brazilian orange
juice concentrates
J. A. McHard
Florida Department of Citrus
Flavor quality of Florida FCOJ following the 1977 January freeze
P. J. Fellers
Florida Department of Citrus
Pounds solids yields after a "democratic" freeze
P. E. Shuler
Florida Crop and Livestock Reporting Service

12:00 N 0 0 N

LUNCH

Chairman Dr. R. F. Matthews
Department of Food Science and
University of Florida
Citrus demand after the 1977 freeze with
1977-78 season
D. S. Tilley and L. H. Myers
Florida Department of Citrus

Human Nutrition

implications for the

Computer mapping of nonproductive citrus trees
G. J. Edwards
University of Florida
Process control for optimizing energy use in the TASTE
A progress report
R. D. Carter
Florida Department of Citrus

evaporator--

Cold pressed orange oil: Effective quality control in the
processing plant
R. J. Braddock and J. W. Kesterson
University of Florida

Effect of

drying on pectin made from lime and lemon pomace
P. G. Crandall, R. J. Braddock, and A. H. Rouse
University of Florida

Variations in ascorbic acid (vitamin C) content in oranges from
different sections of the tree and its effect on the concentration
of this nutrient in FCOJ
E. L. Moore and S. V. Ting
Florida Department of Citrus

INTERPRETATION OF GRAPEFRUIT JUICE COLOR MEASUREMENTS AND PRODUCT
COLOR STANDARDIZATION---R. L. Huggart and D. R. Petrus, Florida
Department of Citrus, Lake Alfred.

Color Measurements.--The feasibility of using a Polar Coordinate
system for grapefruit juice colors is being evaluated. Our preliminary
studies show that the Polar system has some desirable features that will
allow the explanation of what appear to be "misfit" grapefruit juice
colors. When the b/a ratio (a tangent measurement) of the Cartesian
type plane Hunterlab L, b color solid is converted to degrees rotation
(cosine 0 = a/(a2 + b2) /2) in the Polar system, hue data fit into the
Munsell color system very well. The color coordinates rotate clockwise
from greenish white at 10 to 11 o'clock to whites, then yellows at 12
o'clock. The red color measurements of a good 'Burgandy', which are out
of place in a linear system, appears in the 2 to 3 o'clock position where
red colors are expected. A second measurement in the Polar system which
explains the position of 'K-Early' juices is the chroma (intensity of a
color). The chroma is found by extracting the square root of a2 + b2.
The 'K-Early' has the same hue ratio as some of the grapefruit juices.
Its color coordinates using an a/b ratio in a linear equation, place it
with grapefruit juices having the same a/b ratio, but the visual color is
false because of the difference in magnitude of chroma. A phi angle,
calculated as the tangent of chroma/L improves the correlation between
visual color ranking and L, a and b measurements. In preliminary data
from 135 samples examined the past season using the Cartesian coordinate
system visual colors correlated with CR measurements at a coorelation
coefficient of r = 0.948. The addition of CY raised the coefficient to
r = 0.956. CY alone correlated with visual color at r = 0.898. L, a and
b measurements alone correlated with visual at r = -0.142; r = 0.851 and
0.819 respectively. When the Polar system was used, theta correlated
with visual at r = 0.934; enter phi, R = 0.960; enter chroma, R = 0.965.
The main disadvantage of the Polar system is found in calculating theta,
phi and chroma. They can be derived easily with a programmable
calculator, but the system is time consuming when each value is derived
by longhand methods.

Color Standardization.--As part of the grapefruit juice quality
improvement program at the Center, natural colorants have been added to
standardize pink grapefruit juice at an attractive color level approxi-
mating that found in freshly halved 'Ruby' grapefruit. Red colorants
that have been studied include Beet Powder, Grape Skin Concentrate,
Canned Cranberries and "Cactus Apple" Concentrate. A can or bottle of
grapefruit juice was opened, color was adjusted, then the juice in its
respective container was held in a home type refrigerator at 35-400F.
The color of all juices deteriorated very rapidly when held in tin cans
showing a life of less than one week. Juices stored in their glass
package showed a steady loss in color. Initial measurements of a juice
adjusted with cactus apple concentrate were Citrus Red (CR) 44.2 and
Citrus Yellow (CY) 17.3. At the end of five weeks, the color was lighter

and yellower. The measurements had changed to CR 34.9 and CY 25.7.
Color was also noted to fade very rapidly at room temperature (24 hrs.).
A sample exposed to light faded more than a sample protected from light.
All of the colorants reported here are of the anthocyanin group of com-
pounds whose color, appearance and stability depend in part upon the
orientation and number of hydroxyl and methoxyl groups and double bonds
within the molecule. These colorants are known to be very sensitive to
pH, temperature (including heat treatment), metals (tin, iron, copper),
light, ascorbic acid level and apparently will not hold up well in
single strength grapefruit juice in a refrigerator or at room tempera-
ture.

During the past season several concentrated commercial grapefruit
juices were obtained as part of the Grapefruit Juice Survey, so it was
decided to adjust the color of the concentrate and hold it in 2 oz glass
bottles at -5 to + 50F. This approach has been very successful. A
white concentrate, adjusted to an initial color of CR 44.4 and CY 22.1
with Beet Powder, has held its color for 4 months. The CR is unchanged
and the CY has increased very slightly to 24.5.

-5-

DEVELOPMENT OF A COMMERCIAL METHOD FOR THE RECOVERY OF NATURAL COLOR
PIGMENT GRANULES FROM CITRUS JUICES---R. W. Barron, Florida Department
of Citrus, Lake Alfred.

Commercially simulated recovery of natural color pigment granules
were made from 'Dancy' tangerine juice and 'Valencia' orange juice. In
some instances, different methods of finishing were compared to deter-
mine if higher color values as measured on a Hunter Citrus Colorimeter
for natural color pigment granules might be obtained by one method as
compared to another. No differences were found in the tests in which
different methods of finishing were used utilizing the following equip-
ment: an FMC finisher, AMC finisher and Dorr-Oliver screen.

Differences in color values for natural color pigments were found
when an inertial filter was used to remove pulp and the juice was
centrifuged to recover color pigments as compared to when a centrifuge
was used to remove pulp and the juice was then centrifuged to recover
color pigments.

The inertial filter and centrifuge method for color pigment extrac-
tion resulted in color numbers of 0.8 to 1.3 higher than when using the
centrifuge only method.

A REVIEW OF SOME PROCESS AND FORMULA 'PATENTS OBTAINED BY THE FLORIDA
DEPARTMENT OF CITRUS---M. D. Maraulja, Florida Department of Citrus,
Lake Alfred.

Pulp-Free Citrus Bases.--An enzyme and a centrifuge process have
been developed for the preparation of pulp-free bases from either freshly
extracted juices or reconstituted concentrates.

In the enzyme process, the single-strength juices are first heat-
treated to inactivate any enzymes or microorganisms present and the juice
pectins are then partially hydrolyzed by the use of a commercial pecto-
lytic enzyme at 80 to 850F. The reaction is terminated when the serum
viscosity has dropped to 1.40 to 1.45 centipoises by heat treatment again.
The serum is removed from the insoluble solids by decanting and is then
concentrated to 68 to 70Brix and frozen. Approximately 50% of the total
pectins and nearly all of the bottom pulp can be removed by this method
resulting in very low apparent viscosities.
Comparison of Orange Bases and Low Pulp
Concentrates Prepared by Enzyme Process

Base #1 Base #2 Cone. #1 Cone. #2
Brix 650 650 650 800
Pulp-% 0.15 0.4 1.5 2.5
Relative viscosity-cps 1.38 1.46 1.49 1.56
Apparent viscosity-cps 70 71 89 8820

The single-strength juices may be mechanically depulped with a
Westfalia desludge centrifuge. A Model SA7 centrifuge was used with a
juice feed rate of 90 to 115 gallons per hour. The depulped juice wds
then concentrated to 68 to 70Brix and frozen. This method is faster
and more economical but produces bases with higher apparent viscosities
since only water insoluble solids are removed mechanically. The enzymatic
process regulates serum viscosity and more completely reduces ammonium
oxalate soluble and sodium hydroxide soluble pectins to provide bases of
lower apparent viscosities.

Comparison of Juices Before and After Treatment

Cone. Centr. Enzyme Cone. Centr. Enzyme
#1 Process Process #2 Process Process
Apparent Viscosity-cps 11,500 650 203 3100 510 104
Brix 70.00 67.00 67.60 57.70 64.50 64.90
Water Insoluble Solids-
% by wt. .781 .014 .071 .670 .014 .038

Pectic Fractions mg/100 g
Water Soluble 183.8 176.4 209.9 181.2 186.8 211.3
Ammonium Oxalate 100.5 33.9 20.0 80.8 21.3 7.9
Sodium Hydroxide 188.2 23.9 11.2 141.6 3.9 10.7
Total 472.5 234.2 241.1 403.6 212.0 229.9

Citrus Based Thirst Quencher Beverages.--An effective thirst
quencher, besides quenching the thirst, must supplement naturally present
body salts lost during perspiration and must supply a rapidly digestible
high energy natural food such as glucose for quick energy pick up. Two
extended citrus juice thirst quencher beverages have been prepared.

Basic Citrus Thirst Quencher Formulas
Percent By Weight

Citrus Solids
Sweetener
Water
Sodium Chloride
Calcium Chloride
Potassium Chloride
Citric Acid
Flavoring

Grapefruit
3.000
8.500
88.123
0.031
0.014
0.012
0.310
0.010
100.000

Orange
3.110
8.000
88.405
0.031
0.014
0.012
0.410
0.018

(.0389 max.)
(.0166 max.)
(.0146 max.)

100.000

Protein Enriched Orange Juice Products.--The original patented formu-
lations were prepared to resemble and taste as much like orange juice as
possible and contain 3% protein or more by weight. A fat-free protein
concentrate prepared from cheese whey was finally chosen because of its
bland flavor and characteristic low viscosity.

Stabilization of the protein-orange juice beverage was accomplished
by initially combining the hot protein solution with a hot starch solution.
The soluble amylose fraction of the partially hydrolyzed starch forms a
stable complex with the protein prior to the addition of orange juice.

DIFFERENCES IN SOME PHYSICAL AND CHEMICAL CHARACTERISTICS BETWEEN
ORANGE JUICE AND WATER EXTRACT OF ORANGE JUICE PULP---S. V. Ting and
R. D. Carter, Florida Department of Citrus, Lake Alfred.

The water extract of orange pulp or pulp wash solids is a product
of commerce. Its value amounts to millions of dollars each year. Con-
siderable interest on the characteristics of this product has been
expressed by the industry as to its use as an extender of orange juice
in orange juice drink manufacturing.

The practice of recovering soluble solids from the orange juice
pulp by water extraction is quite common in Florida today. Since the
rules affecting the total amount of orange juice that could be legally
obtained from a load of oranges went into effect, light pressure in
finishing the juice has resulted in great improvement in the quality of
Florida orange juice. At the same time it leaves a substantial amount
of soluble solids in the pulp discharged from a finisher as compared to
the use of higher finisher pressures. Regardless of how the juice is
finished, there remains in the pulp a certain amount of soluble solids
which has comparable chemical composition and physical characteristics
to those of the orange juice from the finisher.

In order to determine what proportion of the water extract of
juice pulp has the same characteristics as the first finisher juice, a
number of chemical and physical analyses were made on samples of orange
juice and of pulp wash solids either from the same fruit or from dif-
ferent fruit in our Juice Definition Program. Although no distinct
qualitative differences were found, there were some consistent and
marked quantitative differences in some of these characteristics of
these two products. Among these are Brix/Acid ratios, serum viscosity,
alcohol insoluble proteins, glycoside by the Davis method, various
forms of pectin and color.

Some of these characteristics were chosen during the 1975-76 and
1976-77 seasons to develop an interim method that may be used to more
closely ascertain the amount of orange juice in the water extract of
the corresponding pulp from which the water extract was made. These
characteristics were also chosen on the basis that their analyses are
simple and can be performed by the quality control laboratory of the
plant.

Orange juice concentrate samples from the evaporator and samples
of the corresponding concentrate of the water extract of the pulp
from the same day's production were collected at two week intervals
from several local manufacturing plants during the two seasons. The
measurements made were the Brix/Acid ratio, the total glycoside by the
Davis test, the color measurement by the Hunter Citrus colorimeter,
the total absorbance values of alcoholic solution and the alcohol

-9-

insoluble protein content. The first three analyses can be easily
carried out in most quality control laboratories, the last two will
require additional equipment.

The Brix/Acid ratio of the orange juice is always lower than the
water extract of the same pulp. This has been documented in earlier
studies and is believed to be due to the differences in proportion of
the liquids obtained from various parts of the fruit tissues. Similarly
variations in total glycosides, alcohol insoluble protein and color of
the two products were also attributed to the same explanation. The
simple ratios of these measured characteristics were used as an index to
determine the presence of amount of one component in the others. Since
orange juice is a very complex substance, the use of one or two of these
characteristics can at best be only an attempt for such endeavor for an
approximation. A more precise quantitation of the amount of orange juice
in pulp wash still awaits the establishment of a more definitive descrip-
tion of orange juice far more precise than the present relatively vague
standards of identity.

-10-

COMPARATIVE METAL CONTENTS OF FLORIDA AND BRAZILIAN ORANGE JUICE
CONCENTRATES---J. A. McHard, Florida Department of Citrus,
Gainesville.

Last year at this conference, a relatively new instrument for atomic
emission spectroscopy, the plasma atomic emission spectrometer was des-
cribed. The use of that instrument to measure trace elemental constitu-
ents in ashed orange juice concentrates and some results showing the
elemental composition of several Florida orange juice samples were re-
ported.

A comparison of these trace element compositions of Florida orange
juice and of Brazilian orange juice have been made using this technique.
For many elements there are no significant differences between the juices
from these two sources. However, for a few others, especially barium and
rubidium, there are marked differences, and these differences are shown
to have possible use in distinguishing the geographic sources of these
orange juice concentrates.

-11-

FLAVOR QUALITY OF FLORIDA FCOJ FOLLOWING THE 1977 JANUARY FREEZE---
P. J. Fellers, Florida Department of Citrus, Lake Alfred.

From February 21 to June 6, 1977, samples of FCOJ in 6-oz. cans
representing 7 Florida processors were picked up at random on a regular
basis from several central Florida retail markets for flavor quality
evaluation at the Lake Alfred Center. Twelve experienced taste panel-
ists graded samples on a 9-point hedonic scale at the rate of 3 or 4
per session within a few days of receipt. In all, samples from 7 plants
were tasted 9 times per plant for a total of 63 samples. As it turned
out, 34 samples had been packed prior to the freeze while 29 had been
packed after the freeze. For 2 plants, there were no samples packed
after the freeze. The following table presents some flavor data for the
samples. In general, the flavor of the samples packed after the freeze
compared favorably with those samples packed prior to the freeze both
within plants and overall as may be seen from the table. Plant F
apparently had some problems both before and after the freeze (2 samples
with borderline flavor acceptability packed before the freeze and 3
after) with Plant G having problems to a lesser degree (1 sample before
and 2 after).

Our sampling of Florida commercial FCOJ from the retail market
following the freeze of January 1977, showed no trend of poor juice
reaching retail outlets such as occurred after the 1962 freeze. However,
it should be remembered that this present study was indeed in small
scale and represents just a fraction of the entire pack.

Plants
A B C D E F G
Samples packed prior to
freeze for each plant:
No. 3 9 5 9 2 4 2
Range of flavor scores1 5.8-6.9 5.2-6.7 5.2-6.8 5.9-7.0 5.3-6.4 4.7-6.0 5.4-6.5
Mean flavor scores 6.3 5.9 6.2 6.5 5.9 5.5 6.0

Samples packed after the
freeze for each plant:
No. 6 0 4 0 7 5 7
Range of flavor scores 5.8-6.6 5.6-6.8 5.7-6.9 5.2-6.3 5.0-6.5
Mean flavor scores 6.2 6.3 6.1 5.6 5.7

Mean flavor scores
for all samplesl 6.3 5.9 6.3 6.5 6.0 5.5 5.7

Flavor scores as hedonic categories are as follows: 4 = dislike slightly; 5 -
neither like nor dislike; 6 = like slightly; 7 = like moderately, etc.
20verall unan score for 34 sanplcs packed prior to the freeze 6.1; 29 samples
packed aater the freeze = 6.0; all 63 samples combined = 6.0.

-12-

POUNDS SOLIDS YIELDS AFTER A "DEMOCRATIC" FREEZE---P. E. Shuler,
Florida Crop and Livestock Reporting Service, Orlando.

This report will discuss how forecasts of pounds solids are derived,
the changes in methodology caused by complete area freeze coverage, and
the regression forecasts for spot area freezes vs. "democratic" freeze.

Comparisons of acid, total soluble solids and pounds solids pro-
gressions of the non-freeze (1975-76) with freeze year (1976-77) will
be made.

-13-

CITRUS DEMAND AFTER THE 1977 FREEZE WITH IMPLICATIONS FOR THE 1977-78
SEASON---D. S. Tilley and L. A. Myers, Florida Department of Citrus,
Gainesville.

The 1976-77 season was fairly unique in that it encompassed both a
period of acute over-supply expectations and a period of uncertainty
combined with short supply expectations. The net result was a period of
declining prices and price expectations followed by a period of increasing
prices and the anticipation of further increases later on.

Normally one can, with the proper equations, fairly accurately antic-
ipate the response by consumers to price increases or decreases of a given
amount. This response is, however, conditioned by future expectations as
well as the actual price change. Hence we have the well known terms
"inflationary" and "deflationary" consumer psychology.

This paper represents an attempt to measure the impact of "expecta-
tions" on 1976-77 FCOJ sales and to evaluate the tentative economic
implications for the 1977-78 season under alt-rnative crop size
possibilities.

-14-

COMPUTER MAPPING OF NONPRODUCTIVE CITRUS TREES---G. J. Edwards,
University of Florida, IFAS, Agricultural Research and Education
Center, Lake Alfred.

Multispectral sensing (MSS) is a method that obtains data in multi-
wavelength bands or channels from reflected energy. The MSS instrument
is flown in air craft or space craft.

Selected channels are viewed in a computer analyzing system that
can be trained to differentiate between productive and nonproductive
citrus trees, such as trees under the stress of YTD or other disease.

A ratio of channel 9 to channel 5 data was analyzed and the computer
map generated agreed with the ground observations 86% of the time.

Analysis of channel 11 alone, the thermal channel, agreed 87% of
the time.

The combination of channels 4, 5, 9, and 11 with training on the
nonproductive trees, the advanced YTD diseased trees, gave a computer
map that agreed with the ground observations 96% of the time.

-15-

PROCESS CONTROL FOR OPTIMIZING ENERGY USE IN THE TASTE EVAPORATOR--
A PROGRESS REPORT---R. D. Carter*, Florida Department of Citrus,
Lake Alfred.

During the past year, experimental data have indicated possibil-
ities for the following two control methods:

1. Automatic modulation of the evaporator juice feed on the basis
of electronic refractometer Brix sensing in the third stage of
our -i-stage TASTE Evaporator.

2. Automatic modulation of the steam flow to the steam heated
preheater and the first stage tube, rest on the basis of the
temperature of the steam condensate discharged from these
sources.

We will use experimental run data to develop algorithms to control
the juice evaporation process by the above two modulation methods.

The cable link between the evaporator and the center computer is
being finalized. When completed, automatic data acquisition of TASTE
evaporator experiments with real time analysis and modification of the
process will be possible. Once control programs are developed, we plan
to explore control of the evaporator by microprocessor, which will simplify
commercial application of our work.

On the basis of preliminary experimental runs during the past season,
we believe it possible to save a minimum of 10% heating steam by employing
the equipment shown on the schematic and listing on the following pages.

The savings of 10% steam will amount to approximately $100.00 per
day for 50,000 pounds of water per hour removed by an evaporator.

Equipment shown on the schematic has all been purchased and nearly
all received and installed.

*This project is undertaken with the cooperation of the following AREC
and DOC staff members: Dr. B. S. Buslig, Dr. P. G. Crandall, Dr. B. A.
Eagerman, Mr. G. J. Edwards, Dr. W. M. Miller and Dr. T. A. Wheaton.

-16-

A SCHEMATIC FOR OPTIMIZING HEATING ENERGY USE IN THE TASTE CITRUS
JUICE EVAPORATOR

Cooperative Research Initiated July 1976
Florida Department of Citrus and
University of Florida Agricultural Research
and'Education Center, Lake Alfred

FLO\ FLOW PR'-ATR BRI
CONTROL SENSING S ENR SE I G

O 0

-17-

COMPONENTS OF A SYSTEM FOR OPTIMIZING HEATING ENERGY USE
IN THE TASTE CITRUS JUICE EVAPORATOR (see schematic)

Florida Department of Citrus and the University of Florida,
Agricultural Research and Education Center, Lake Alfred, FL 33850

A) Reliance Variable Speed Motor and Drive Controller
Barney's Pumps Inc., Lakeland, FL 33802

B) Flowmeter, Positive Volumetric Measuring Type, with Totalizer
and Electronic Register
Accurate Metering Systems Inc., Elk Grove Village, IL 60007

C) Air Operated Steam Valve
Taylor Instrument Co., Rochester, NY 14650

D) Differential Pressure Cell and Transmitter System, Foxboro Inc.
1851 Executive Center Drive, Jacksonville, FL 32207

E) Copper Constantan Thermocouple
Various Suppliers

F) Model 47 Process Refractometer, Anacon Inc.
30 Main Street, Ashland, MA 01721

G) Wide-Range A/D Converter and Input Controller System, Computer
Products Inc., 1400 N.E. 70th Street, Ft. Lauderdale, FL 33307

H) Model 16/65 Minicomputer, General Automation Inc.
1055 Southeast Street, Anaheim, CA 92805

I) Impact Printer, Model EDT 1200 KSR
Western Union Data Service, Cleveland, OH 44122

J) Digital to Analog Converter, W. A. Brown Instruments Inc.
P. O. Box 513, Orlando, FL 32802

K) Pulse Converter, W. A. Brown Instruments Inc.
P. O. Box 513, Orlando, FL 32802

L) Electro-pneumatic Converter, Leeds & Northrup Inc.
7000 Lake Ellenor Drive, Orlando, FL 32809

-18-

COLD PRESSED ORANGE OIL: EFFECTIVE QUALITY CONTROL IN THE PROCESSING
PLANT---R. J. Braddock, and J. W. Kesterson, University of Florida, IFAS,
Agricultural Research and Education Center, Lake Alfred.

Cold pressed orange oil quality may be affected by many variables.
Some of the more important ones to be considered are listed and described
as follows:

1. Fruit quality. Firm, mature fruit of best quality will produce the
best quality oil. Aldehyde content of the oil will be lower for
immature and overmature oranges.

2. Quantity of water used to make the oil-water emulsion. The aldehyde
content decreases with increasing quantity of aqueous phase in an
emulsion. This decrease, in part, may be due to insoluble solids
in the water absorbing aldehydes. However, using larger quantities
of water will increase oil yields. Therefore, a balance should be
sought between aldehyde content, water usage and oil yield.
Current industry water usage for oil recovery varies widely above
and below 3 gal/box depending on the type of recovery equipment.

3. Oil yield. Specific gravity, evaporation residue and refractive
index of an oil increase with increasing yield. Optical rotation
decreases with increasing yield. Occasionally, oils will not
meet certain of the U.S.P. specifications because the yields
are too high or low.

4. Condition of the emulsion. When emulsions are held for any length
of time under conditions allowing microorganism growth, souring
prior to desludging or polishing can occur. This will result in
poor quality oil.

5. Type of fruit processed. This variable can be controlled by not
processing mandarin or other varieties in with oranges. Subtle
flavor differences, which can be detected by the flavorist may be
imparted to orange oil adulterated with tangelos, murcotts, temples,
or tangerines. Adulteration with these fruit may easily be detected
by UV spectra, and results in inconsistent quality and variable
aldehyde contents.

6. Storage and handling of the finished oil. Storage under nitrogen,
at temperatures around 70-75F is adequate to maintain quality of
properly manufactured, previously dewaxed, cold pressed oils.
Exposure to air (oxygen) and certain metals (copper, iron, etc.)
can result in oxidation leading to chemical deterioration of the
oil. Oil should not be put into unclean drums, drums containing
water, or drums which may have contained concentrate. Occasionally,
someone puts the product into drums where iron comes into contact

-19-

with certain chemicals in the oil. The result is chemical degra-
dation producing dark brown, black or fishy smelling oil.

7. Drum handling. Keep drums filled with oil to minimize air space.
Don't use half of the oil in a drum, then put the drum back into
storage to be brought out at a later time. Oxidation of the re-
maining oil in the drum can occur during restorage, making the
oil unfit for use.

Yield of oil, or the percent of oil recovered from the total oil
in the fruit is a major concern of processors. Quality control checks
of the process can be made at certain critical steps during production.
These are discussed as follows:

1. Analyze and determine the total oil in a random sample of the fruit
to be processed. Either the Scott or Clevenger method may be used
for oil analyses. Express the oil as lbs oil/ton fruit.

2. Measure the amounts of oil (lb oil/ton fruit) in the emulsion feed
to the desludger centrifuge, the concentrated emulsion from the
centrifuge, the ring dam effluent and the discharge. Centrifuge
efficiency can be calculated from this information. It will be
necessary to know liquid volumes feeding and leaving the centrifuge.

3. Oil from the polishers can be quantitated by weighing a sample
collected in a specific time (lb oil/ton fruit).

You may be surprised to find that your plant is losing more oil
than you make, or that your recovery is reasonable. It should be
possible to recover better than 50% of the oil in the fruit as
cold pressed oil. For Valencias, this would mean putting approxi-
mately 7 lb oil/ton fruit in the drum.

4. Determine the oil content (lb oil/ton fruit) of fruit and juice
fractions after oil has been extracted. These will vary depending
on equipment, but usually include peel residue, juice and pulp.
These measurements are necessary to determine where losses occur
and to monitor the efficiency of the whole process. For instance,
the total oil in the dilute emulsion plus the amount remaining in
the peel residue plus the amount that gets in the juice should be
approximately equivalent to the total oil in the fruit.

Because of the importance to flavor quality, aldehyde contents of
oils are routinely determined in the quality control laboratory. There
has been a recent change in the official U.S.P. procedure for determining
aldehyde contents of orange oils. The analysis is performed as follows:

-20-

"Dissolve 4.5 g of hydroxylamine hydrochloride in 13 ml of water,
add 85 ml of tertiary butyl alcohol, mix and adjust with 0.5 N potassium
hydroxide to pH 3.4. Pipet 50 ml of this solution into a flask con-
taining 5 ml oil, accurately weighed. Stopper the flask, allow to stand
30 min at room temperature, with occasional shaking. Titrate the liber-
ated hydrochloric acid with 0.5 N alcoholic potassium hydroxide to pH
3.4. Each ml of KOH consumed in the titration is equivalent to 78.13
mg total aldehydes, expressed as decanal." Complete analytical pro-
cedures, as well as standards for orange oil quality are available in
the United States Pharmacopeia. 1975. Nineteenth Revision. Mack
Publishing Company. Easton, PA 18042.

-21-

EFFECT OF DRYING ON PECTIN MADE FROM LIME AND LEMON POMACE---
P. G. Crandall, R. J. Braddock, and A. H. Rouse, University of Florida,
IFAS, Agricultural Research and Education Center, Lake Alfred.

Currently there are approximately 3600 metric tons (4,000 short
tons) of dried pectin pomace being made annually from Florida's lime
and lemons. The pectin pomace process involves leaching the peel with
water, pressing and then drying the peel for later pectin extraction.
Samples of approximately 350 kg of commercially leached lime and lemon
peel were dried under controlled conditions at temperatures between
370-540C (700-1000F) to final moisture contents ranging from 3-20%.
The quality of the extracted pectin was compared among these samples
and the pectin quality was compared with commercially leached and dried
samples which served as controls.

We measured the change in pectin quality by determining the jelly
units (jelly grade multiplied by % pectin yield). The average jelly
units for fresh, commercially leached lime peel was 92.9. Upon drying,
this peel dropped to 79.9. For lemon peel, we found a similar drop in
jelly units from 74-63.9 upon drying. When we leached fresh peel in
the laboratory, we found 98.3 jelly units for the lime and 83.8 for the
lemon. When this peel was dried in our pilot plant dryer to a final
moisture of 15-20%, the jelly units dropped to 61.6 for lemon pomace.
Upon further drying to 8-12% moisture, the jelly units were 85.4 and
61.7 for lime and lemon. For moistures of 3-6%, lime and lemon jelly
units dropped still further to 55.5 and 37.6 respectively. Addition-
ally, we found we could not dry pectin pomace acceptably without a
uniform particle size and using, recycle through the dryer.

At the conclusion of this experiment, we feel there may be advant-
ages in selling pectin pomace on a jelly unit basis rather than on a
per ton basis. We further feel there may be advantages in making pectin
from fresh peel and avoiding the losses in pectin quality and the costs
of drying and shipping the pectin pomace.

-22-

VARIATIONS IN ASCORBIC ACID (VITAMIN C) CONTENT IN ORANGES FROM
DIFFERENT SECTIONS OF THE TREE AND ITS EFFECT ON THE CONCENTRATION
OF THIS NUTRIENT IN FCOJ---E. L. Moore and S. V. Ting, Florida
Department of Citrus, Lake Alfred.

H. J. Reitz and J. W. Sites (Proc. Florida State Hort. Soc.
61:80-90. 1948) in a classical experiment determined the quality of
each individual orange (over 1800) on a single 28 year old Valencia
orange tree on rough lemon rootstock. Fruit were classified for
location on tree when picked during a 6-day period in March, 1948.

Reproduced below are the original presentations by Reitz and
Sites for the average values for soluble solids and ascorbic acid in
fruit from different sections of the tree. Using these values, the
corresponding ascorbic acid values based on the 12.80Brix value for
reconstituted FCOJ were calculated. The differences in average values
for ascorbic acid in the fruit from different sections of this one
tree were minimized in the standardized 12.80Brix level for reconsti-
tuted FCOJ.

11.21 ) 41.2 3 47.3

9.93 / 1.50 33.8 \43.4 44.1 \4 8.6

8.70 30.0 44.9

%SOLUBLE ASCORBIC ACID ASCORBIC ACID
SSOLIDS mg/100 ml mg /100 mi

Average of all Fruit=10.2 Average of all Fruit =37.1 Average of all Fruit=46.8
Data of Reitz and Sites
at left recalculated for
32.8% soluble solids
Average values for different sections of the tree. Values for top and
outside fruit are averages of all fruit so classified. Other values represent
averages of all fruit in the area where the figure is located.

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