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Citrus Station Mimeo Report CES 65-9
October 6, 1964
Questions for Consideration in the Use of Natural Flavor-Enhancement Materials
in Frozen Concentrated Orange Juices
F. W. Wenzel and R. W. Olsen
Florida Citrus Experiment Station
and
R. W. Wolford and C. D. Atkins
Florida Citrus Commission
Lake Alfred, Florida
In the presentation of the previous paper, Wolford has indicated the various
natural flavor-enhancement materials that may be mixed with orange concentrate
from commercial evaporators so that frozen concentrated orange juice will contain
volatile substances responsible for the very good aroma and flavor of freshly ex-
tracted orange juice. Some of these flavor-enhancement materials have been used
for a considerable number of years. These include cutback juice (6) and cold-
pressed orange oil (3). Orange essence and freeze-concentrated cutback juice
have more recently been used in Florida in the commercial production of frozen
concentrated orange juice. Walker (9) reviewed the subject of fruit juice
essences which are commercially produced by the recovery of the volatile flavor
constituents of fruit juices, such as apple, pineapple, grape and citrus juices.
Joslyn (2) summarized considerable information on the concentration of fruit
juices by freezing. The materials which have been most recently investigated and
can now be produced by centrifugation of orange juice so that they may be used
for flavor-enhancement of citrus products, including frozen concentrated orange
juice, are juice emulsion and juice oil. Thrush (8) of the DeLaval Separator
Company discussed the use of centrifuges to recover citrus juice oils. Lawler
(5) presented considerable information about the production and possible uses
for juice emulsion. Distelkamp of Centrico, U. S. distributor for Westfalia, and
McDuff, director of research and quality control at Adams Packing Company,
Auburndale, Florida, filed a patent application in November, 1962. The patent is
assigned to Westfalia Separator. The process of producing and using citrus juice
emulsions is covered by the patent application.
It is generally recognized that flavor improvement of frozen concentrated
orange juice is necessary to maintain the extensive, favorable consumer acceptance
it has had since it was first marketed as a new product during the 1945-46 season.
Also, because of increasing competition from other fruit juices and a continually
increasing number of juice products, citrus processors must produce frozen concen-
trated orange juice with very good flavor at the lowest possible cost. To do this
the juice yield from oranges must be maintained as great as possible without caus-
ing flavor deterioration in the flavor of this product. It is anticipated that
in the future all types of natural flavor-enhancement materials will be investi-
gated as a means of improving the flavor of frozen concentrated citrus juices.
Florida Citrus Experiment Station
and Florida Citrus Commission,
Lake Alfred, Florida
400-10/6/64 FWW
-2-
More questions can be asked at this time than can be answered relative to
natural flavor-enhancement materials, which may be used in the production of
frozen concentrated orange juice, and this is especially true concerning such
materials as essences, juice emulsions or juice oils. A partial list of such
questions would include the following. How is each of these materials produced?
How can they best be used to improve the flavor of frozen concentrated citrus
juices? What is the composition of such products? What is their physical,
chemical and flavor stability, both initially and after storage under various
conditions, such as time and temperature? Can these flavor-enhancement materials
be produced so that their characteristics may be standardized and are quality
control procedures available? How will the use of such products in frozen con-
centrate affect the chemical, physical and flavor characteristics of the concen-
trate, initially and after storage under both good and poor storage conditions?
Some answers to the above questions will be found in the few references
previously indicated or in many reports in the literature about these flavor-
enhancement materials which are not mentioned in this paper. However, the
answers to many of these questions will not be available until additional
studies provide the large amount of data on which such answers can be based.
Wolford, Attaway and their coworkers at this Station have published many
papers during recent years concerning the isolation and identification of
volatile substances that effect the aroma and flavor of orange juice. Results
of some studies during the past year on this subject were reported today by
Wolford in a previous paper.
The chemical method discussed also today by Dougherty may possibly be a
means of determining and controlling the water-soluble volatile constituents
in various flavor-enhancement materials.
Comparison of the flavor of frozen concentrated orange juices containing
some flavor-enhancement materials. Evaluation of the flavor of experimental
packs of frozen concentrated orange juice, containing various flavor-enhancement
materials and packed both at this Station and in a commercial plant, was made
during the past year. The concentrates were prepared from both Pineapple and
Valencia oranges.
Pineapple orange juice was concentrated in the Station pilot plant to
550 Brix. Four concentrates were then prepared from this 550 Brix product
by the addition of (a) cutback juice and coldpressed orange oil, (b) essence,
(c) juice emulsion (Centrico), and (d) juice oil (DeLaval). These products
were then frozen and stored at -80F. until used. Similar experimental packs
of frozen concentrated Valencia orange juice were also prepared; also, an
additional concentrate was made using both essence and coldpressed oil.
The flavor of samples of three experimental packs of frozen concentrated
Valencia orange juice, which were processed in a commercial plant, was also
evaluated. These concentrates were made from the same 580 Brix concentrate
to which was added (a) cutback juice and coldpressed orange oil, (b) cutback
juice and juice emulsion (Centrico) and (c) only juice emulsion which resulted
in a 570 Brix concentrate.
Florida Citrus Experiment Station and Florida Citrus
Commission, Lake Alfred, Florida. 400-10/6/64 FWW
The flavor of the reconstituted frozen concentrated orange juices were
graded by a taste panel. Two types of tests (1) were used (a) scalar scoring
and (b) triangular. The numerical scoring of the flavor of the reconstituted
juices was as follows, 10 = excellent, 9 = very good, 8-7 = good, 6-5 = fair,
4-3 = poor, 2 = very poor, and 1 = unpalatable. Results are interpreted on
the basis that (a) a juice scored 4 or lower would not be repurchased by the
panel member, (b) differences in flavor resulting in successive descriptive
terms or the corresponding numerals would be detectable by most consumers and
(c) differences in flavor resulting in the use of either one of the two
numerals corresponding to any one descriptive term, such as 8-7 = good, are
small and would be of little concern to most consumers. In using the tri-
angular test, whenever a taster correctly separated the odd sample, he was
requested to score the two juices used in the test to indicate his preference,
Results of the flavor evaluation of all of the frozen concentrated orange
juices prepared for this study, using various flavor-enhancement materials,
are presented in Tables 1-9. Tables used for determining the level of statis-
tical significance for results obtained from the triangular tests were those
of either Roessler (7) or Kramer and Twigg (4).
When triangular tests were used to determine differences in flavor of
reconstituted frozen concentrated Valencia orange juices containing various
flavor-enhancement materials, significance levels, shown in Table 1, indicate
that there were differences in flavor between the reconstituted Valencia
juice, containing cutback juice and coldpressed orange oil, and all of the
other juices. The largest flavor differences indicated were between the con-
trol concentrate (cutback juice and c.p. oil) and those to which either essence
or essence and c.p. oil had been added. The flavor difference was the smallest
between the control concentrate and that in which juice oil was used. Based
on the flavor grades given by those tasters who separated the samples correctly,
the control concentrate was preferred to each of the other four products. It
should be pointed out .that the control concentrate was cutback from 600 Brix
to 420 Brix, rather than to 500 Brix as in the case of the other four concen-
trates, and, therefore, the reconstituted juice contained 10% cutback juice
which.was more than that in the other juices.
The average flavor grades, shown in Table 2, for the Valencia concentrates
indicated that those containing cutback juice and c.p. oil, essence and c.p.
oil, or juice oil had a good flavor, whereas when essence or juice emulsion
were used a fair flavor resulted. When similar concentrates, Table 3, made
from Pineapple oranges, were scored, the flavor of the reconstituted juice con-
taining cutback juice and c.p. oil was good, but that of the other three juices
was fair.
The results of triangular tests (Table 4) showed that flavor differences
existed in the various pairs of concentrates compared, except in the pair when
one contained juice emulsion and the other juice oil. Frozen Valencia orange
juices containing juice emulsion, juice.oil, or essence and c.p. oil were pre-
ferred over that in which essence alone was used. The products containing
essence and c.p. oil were preferred over those in which juice emulsion, juice
Florida Citrus Experiment Station
and Florida Citrus Commission,
Lake Alfred, Florida.
400-10/6/64 FWW
oil or only essence were used. In three comparisons, the levels of signifi-
cance indicated that greater flavor differences occurred when essence and c.p.
oil were added to the concentrate.
When a good flavored 1964 late season commercial frozen concentrated
orange juice was compared with experimental samples of Valencia concentrates
containing various flavor-enhancement materials, triangular test data indi-
cated (5) that (a) there was no flavor difference between it and a concentrate
containing juice oil, (b) flavor differences were indicated between the
commercial sample and experimental samples containing essence, juice emulsion,
or essence and c.p. oil and (c) tasters preferred the commercial product
rather than that with the essence; however, the concentrates containing either
the juice emulsion or the essence and c.p. oil were preferred rather than the
commercial concentrate.
No practical differences in flavor were found when frozen concentrated
orange juices containing various flavor-enhancement materials, as indicated
in Table 2, were stored for 24 hr. at 800F. then reconstituted and the flavor
of the juices scored by the taste panel. However, as shown by the triangular
test data reported in Tables 6 and 7, flavor differences were indicated after
the various frozen concentrates were stored for 24 hr. at 800F.
Neither triangular test data nor scalar scoring by a taste panel (Tables
8 and 9) showed any flavor differences between frozen concentrated Valencia
orange juices, packed in a commercial plant, and that containing either cut-
back juice and c.p. orange oil or juice emulsion. Flavor scores decreased
when these products were stored for 24 hr. at 800F. even though one of them
was a 570 Brix product; also, there was no difference in the flavor of the
three concentrates after they had been stored under the above conditions.
Considering all of the flavor evaluation results, reported in Tables
1-9, the following indications become evident. There is little evidence
that frozen concentrated orange juices produced, using such flavor-enhance-
ment materials as essence, essence and coldpressed oil, juice emulsion or
juice oil have a better flavor than concentrates made using cutback juice
and coldpressed orange oil. Differences in the flavor of the concentrates
in which essence and coldpressed orange oil were used were greater than
that in products containing juice emulsion, juice oil or essence; also, that
tasters preferred this product rather than any of the other three concen-
trates. Marked flavor differences in the concentrates which contained either
juice emulsion or juice oil were not indicated from the results obtained
using either triangular tests or scalar scoring. When essence alone was used
as a flavor-enhancement material, marked flavor differences were usually found
in these products and concentrates containing other materials were usually
preferred.
Storage of frozen concentrated orange juices for 24 hr. at 800F. resulted
in flavor differences between some of the products, especially those containing
only essence; however, in most of the cases when essence was used such concen-
trates were not preferred.
It is hoped that these flavor evaluations of frozen orange concentrates
containing flavor-enhancement materials may serve as a guide for any processor
who is interested in using such material.
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References
1. Institute of Food Technologists, Committee on Sensory Evaluation.
Sensory testing guide for panel evaluation of foods and beverages. Food
Technol. 18, 1135-1141 (1964).
2. Joslyn, Maynard A. Concentration by freezing. Chapter 10, Fruit
and Vegetable Juice Processing Technology. Donald K. Tressler and Maynard
A: Joslyn. The Avi Publishing Compnay, Inc., Westport, Conn. 1961.
3. Kesterson, J. W. and R. Hendrickson. Essential Oils from Florida
Citrus. Florida Agricultural Experiment Station Bulletin 521. 1953.
4. Kramer, Amihud and Bernard A. Twigg. Fundamentals of Quality
Control for the Food Industry. The Avi Publishing Company, Inc., Westport,
Conn. 1962.
5. Lawler, Frank K. Centrifuges flavor from juice. Food Engineering,
36, (8), 42-45 (1964).
6. MacDowell, L. G., E. L. Moore, and C. D. Atkins. Method of preparing
full-flavored fruit juice concentrates. U.S. Pat. 2,453,109. Nov. 9, 1948.
7. Roessler, E. B., Warren, J., and Guyman, J. F. Significance of
triangular taste test. Food Research 13, 503-506 (1948).
8. Thrush, Robert E. Application of centrifuges in the recovery of
citrus flavor fractions. Paper presented at Citrus Engineering Conference,
Florida Section, Am. Soc. Mech. Engineers. Lakeland, Fla. March 25, 1964.
9. Walker, L. H. Volatile flavor recovery. Chapter 12. Fruit and
Vegetable Juice Processing Technology. Donald K. Tressler and Maynard A.
Joslyn. The Avi Publishing Company, Inc., Westport, Conn. 1961.
Florida Citrus Experiment Station
and Florida Citrus Commission,
Lake Alfred, Florida.
400-10/6/64 FWW
Table 1. Comparison of flavor of experimental frozen concentrated Valencia
orange juices containing either cutback juice and coldpressed oil or other natural
flavor-enhancement materials
Type of test Triangular
Significance
level
Preferences
Sample
Cutback juice and c.p. oil vs. essence
0.1%
cutback + oil
Cutback juice and c.p. oil vs. juice emulsion
6 1% cutback + oil
Cutback juice and c.p. oil vs. juice oil
3 5% cutback + oil
Cutback juice and c.p. oil vs. essence and c.p. oil
0.1%
cutback + oil
Preference as indicated by flavor grades given by tasters who separated the
samples correctly.
Table 2. Flavor grades for experimental frozen concentrated Valencia orange
juices containing either cutback juice and coldpressed oil or other natural
flavor-enhznacment materials
Concentrate
contains
oBrix
Total tasting
Average grade
Flavor
Total tasting
Average grade
Flavor
Total tasting
Average grade
Flavor
Type
Cutback juice
and c.p. oil
420
of test Scalar scoring
Essence Juice
emulsion
500 500
Juice
oil
500
Concentrate stored at -80F.
137 124 109 107
6.9 6.1 6.3 6.6
Good Fair Fair Good
After storage for 24 hr. at 800F.
23 24 35 24
5.9 5.5 5.7 6.2
Fair Fair Fair Fair
After storage for 96 hr. at 400F.
15 15
6.8 5.6
Good Fair
15
6.0
Fair
15
6.4
Fair
Essence and
c.p. oil
500
114
6.6
Good
36
5.7
Fair
15
6.1
Fair
Table 3. Flavor grades for experimental frozen concentrated Pineapple
orange juices containing either cutback juice and coldpressed oil or other
natural flavor-enhancement materials
Type of test Scalar scoring
Concentrate Cutback juice Essence Juice Juice
contains and c.p. oil emulsion oil
OBrix 420 470 500 500
Concentrate stored at -80F.
Total tasting 118 25 27 26
Average grade 6.8 5.4 5.7 6.2
Total
tests
Correctly
separated
Tests
Fair Fair
Flavor
Good
Fair
Fair
Fair
Table 4. Comparison of flavor of experimental frozen concentrated Valencia
orange juices containing various natural flavor-enhancement materials
Type of test Triangular
Significance
level
Preference1
Sample
Total
tests
17
Tests
9
9
8
6
9
Preference as indicated by flavor grades given by tasters who separated the
samples correctly.
Table 5. Comparison of flavor of experimental frozen concentrated Valencia
orange juices containing various natural flavor-enhancement materials with that
of a commercial product
Type of test Triangular
bal Correctly Significance Preferencel
sts separated level Sample
Commercial frozen concentrated orange juice2 vs. essence
6 5 5% commercial
Commercial frozen concentrated orange juice2 vs. juice emulsion
5 5 1% juice emulsion
Commercial frozen concentrated orange juice2 vs. juice oil
none
Tests
3
commercial
Commercial frozen concentrated orange juice vs. essence and c.p. oil
6 5 5% essence + oil 5
Preference as indicated by flavor grades given by tasters who separated the
samples correctly.
2
Flavor of this commercial product was graded "good" by flavor panel.
Florida Citrus Experiment Station
and Florida Citrus Commission,
Lake Alfred, Florida.
400-10/6/64 FWW
Essence vs. juice emulsion
0,1% emulsion
Essence vs. juice oil
1% juice oil
Essence vs. essence and c.p. oil
0.1% essence + c.p. oil
Juice emulsion vs. juice oil
none juice oil
Juice emulsion vs. essence and c.p. oil
0.1% essence + c.p. oil
Juice oil vs. essence and c.p. oil
0.1% essence + c.p. oil
Correctly
separated
To1
tes
Table 6. Comparison of flavor of experimental frozen concentrated Valencia
orange juice containing essence and coldpressed oil with that of products containing
other natural flavor-enhancement materials after storage for 24 hr. at 80F.
Type of test Triangular
Correctly Significance Prefe
separated level Sample
Essence and c.n. oil vs. cutback and c.n. oil
rence
rence
Tests
5 5% cutback + oil
Essence and c.p. oil vs. essence
5 5% essence
Essence and c.p. oil vs. juice oil
7 0.1% essence + c.p, oil
Essence and c.p. oil vs. juice emulsion
Total
tests
7
7
7
5
no preference
Table 7. Comparison of flavor of experimental frozen concentrated Valencia
orange juices containing juice emulsion with that of products containing other
natural flavor-enhancement materials after storage for 24 hr. at 800F.
Type of test Triangular
Significance
level
Preference1
Sample
Juice emulsion vs. cutback juice and c.p. oil
6 1% cutback + oil
Juice emulsion vs. essence
7 0.1 emulsion
Juice emulsion vs. juice oil
1% j
uice oil
1
Preference as indicated by flavor grades given by tasters who separated the
samples correctly.
none
Total
tests
Correctly
separated
Tests
Florida Citrus Experiment Station
and Florida Citrus Commission,
Lake Alfred, Florida.
400-10/6/64 FWW
Table 8. Comparison of flavor of experimental samples of frozen concentrated
Valencia orange juices, packed in a commercial plant, containing either cutback
juice and coldpressed oil or juice emulsion
Type of test Triangular
Total Correctly Significance Preference1
tests separated level Sample Tests
Cutback juice and c.p, oil vs. cutback juice and juice emulsion
34 15 none no preference
Cutback juice and c.p. oil vs. juice emulsion
33 15 none no preference
Cutback juice and juice emulsion vs. juice emulsion
33 12 none no preference
Preference as indicated by flavor grades given by tasters who separated the
samples correctly.
Table 9. Flavor grades for experimental samples of frozen concentrated Valencia orange juices,
packed in a commercial plant, containing either cutback juice and coldpressed oil or other natural
flavor-enhancement materials
Type of test Scalar scoring
Concentrate
contains
OBrix
Total tasting
Average grade
Flavor
Total tasting
Average grade
Flavor
Cutback juice
and c.p. oil
420
Juice
emulsion
570
Cutback juice
and juice emulsion
420
Other commercial concentrates
No. 1 No. 2
420 420
Concentrate stored at -80F.
105 105 105 37
6.4 6.4 6.4 7.1
Fair Fair Fair Good
After storage for 24 hr. at 800F.
17
5.2
Fair
17 17
5.8
Fair
5.7
Fair
10
6.3
Fair
37
6.6
Good
10
6.2
Fair
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