Group Title: Citrus Station mimeo report - Florida Citrus Experiment Station ; 55-6
Title: Chemical and physical qualities of commercial samples of frozen concentrated orange juice
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 Material Information
Title: Chemical and physical qualities of commercial samples of frozen concentrated orange juice
Series Title: Citrus Station mimeo report
Physical Description: 2, 11 leaves : ill. ; 28 cm.
Language: English
Creator: Rouse, A. H
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: 1954
 Subjects
Subject: Frozen concentrated orange juice -- Quality -- Florida   ( lcsh )
Genre: government publication (state, provincial, terriorial, dependent)   ( marcgt )
non-fiction   ( marcgt )
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Statement of Responsibility: A.H. Rouse ... et al..
General Note: Caption title.
General Note: "Oct. 12, 1954."
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Bibliographic ID: UF00072368
Volume ID: VID00001
Source Institution: University of Florida
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Resource Identifier: oclc - 74328914

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Citrus Station Mimeo Report 55-6
Oct. 12, 1954


Chemical and Physical Qualities of Commercial Samples of Frozen
Concentrated Orange Juices

A. H. Rouse, C. D. Atkins, E. L. Moore, and R. W. Olsen


A survey concerned with pectin analyses, pectinesterase activity, clarifi-
cation, and gelation was made during the 1953-54 season on commercial samples of
frozen concentrated orange juices. A total of 221 commercial samples were ana-
lyzed from 23 concentrate plants in Florida. From 16 of these manufacturers,
which represented the majority of the frozen concentrated orange juice product-
ion in Florida, 9 to 14 samples were obtained for testing from each processor
during the months of December 1953 through June 1954. This accounted for 177
samples or 80f of the commercial samples received. Collection of 2 to 9 samples
from each of the other 7 plants accounted for the remaining 20%.

The quantity of pectic substances was estimated by a colorimetric method
after being divided into 3 groups on the basis of their solubility at room temp-
erature in water (H20), in ammonium oxalate ( (NH4)2C204 ), and in sodium hy-
droxide (NaOH). Pectins are expressed as anhydrogalacturonic acid (AGA) in
g./l0 g. of concentrate and as percentage total pectin. Pectinesterase activi-
ty is expressed as (PE.u.) X 104 per g. of reconstituted juice.

Clarification and gelation were determined on the concentrate samples immed-
iately after thawing, after storage for 72 hr. at 400F., and also after storage
for 24 hr. at 80OF.

Data presented in Table 1 show the average values of pectin and pectinester-
ase activity in commercial samples of 16 plants from which 9 or more samples were
received during the season. Results of the survey from the 16 plants show that
water-soluble pectin ranged from 28.0 to 44.1%, oxalate-soluble pectin from 19.7
to 30.6o, and protopectin as sodium hydroxide-soluble pectin from 34.2 to 42.8%
of the total pectin. Average values of pectinesterase activity varied from a
low of 5.9 to a high of 26.5 units.
Analyses of commercial samples, indicating partial inactivation of the en-
zyme, from a plant producing frozen concentrated orange juices are shown in Table
2. Data in Table 3 would indicate that no enzymic inactivation resulted in
samples of frozen concentrated orange juices manufactured by this plant. It is
of interest to note that the water-soluble pectins in samples shown in Table 2
were protected from demethylation when compared to the water-soluble pectins in
samples listed in Table 3. Also the oxalate-soluble pectins were found to be of
lower values in concentrate samples presented in Table 2, as compared to the
oxalate-soluble pectins in samples shown in Table 3. This would signify that
concentrates with high oxalate-soluble pectin are more likely to gel when thawed
than concentrates of lower values for this pectic fraction. Pectinesterase
varied from 4.2 to 9.0 units in the samples presented in Table 2, indicating
Florida Citrus Experiment Station
and Florida Citrus Commission
Lake Alfred, Florida. 5230 10/12/54 AHR





-2-


partial inactivation of the enzyme, whereas samples in Table 3 ranged from 19.6
to 33.0 units indicating slight or no inhibiting influence on -.he enzyme.
Relationships of the pectic fractions to cloud and gel stability in commer-
cial samples of frozen concentrated orange juices are presented in Table 4. The
table is divided into 3 parts: (a) showing a group of sample; with low percent-
age of water- to high oxalate-soluble pectin, (b) another group of samples with
a high water- to low oxalate-soluble pectin, and (c) samples with equal amount
of water- to oxalate-soluble pectin. After storage for 72 hr. at 400F. all of
the concentrate samples showed definite or extreme. clarification except for those
concentrates with high water- to low oxalate-soluble pectin. Only under severe
storage at 800F. for 24 hr. did one concentrate sample of high water- to low
oxalate-soluble pectin result in extreme clarification and form a semi-gel. This
sample of concentrate contained a relative high pectinesterase activity.:

Selected commercial samples of frozen concentrated orange juice having dif-
ferent characteristics are shown in Table 5. For example, a sample of concen-
trate having the highest activity of FE.u. contained the greatest amount of oxa-
late-soluble pectin which resulted in a so?.id gel after 72 hr. at 400F. storage.
The commercial sample with the least pectinesterase activity contained a low
quantity of oxalate-soluble pectin which resulted in no gelation after storage
at 80OF. for 24 hr.

Correlation of pectic content in reconstituted centrifuged juice to cloud
and relative viscosity are graphically presented in Figures 1 and 2. Relative
viscosity was determined using an Ostwald pipette tube at 260C. The points on
the graph represent data from 18 commercial samples of frozen concentrated
orange juices.

Slope of the curve in Figure 1 would illustrate that a pectin concentration
of 25 mg. per 100 g. of reconstituted centrifuged orange juice produced a cloud
of approximately the same light transmission as a juice with double that amount
of pectin. Figure 2 indicates that the viscosity measurement of reconstituted
centrifuged orange juice can be a means of estimating the pectin concentration
and thus indirectly a measurement of cloud..

Tables 6 12 give results on pulp content, pH values, gelation, clarifica-
tion, and vacuum or pressure of the 221 cans of frozen concentrated orange juices
gathered in the survey.

Co-workers also have data on acid, total soluble solids, peel oil, glucoside
content, flavor, color, diacetyl content, and microbiological count; with the
exception of some results on color, these data are not being presented at this
time. This information is now being compiled and will be given at a later date.








Florida Citrus Experiment Station and
Florida Citrus Commission, Lake Alfred, Fla.
523f 10/12/54 AHR









TABLE 1
Comparison of the average values for pectin and pectinesterase in frozen concentrated
orange juices from 16 Florida plants for the 1953-54 season

St IPectin as anhydrogalacturonic acid g./l00 g. cone. Percentage of total pectin (PE.u.)g.
Plant soluble in soluble in reconstituted
SH20 (NH4)20204 NaOH Total H20 (NH4)20204 NaOH juice X 104
A 0.135 0.073 0.138 0.346 39.0 21.1 39.9 6.3
B 0.1U4 0.057 0.101 0.272 41.9 21.0 37.1 6.3
0 0.112 0.055 0.106 0.273 41.0 20.2 38.8 6.7
D 0.120 0.058 0.116 0.294 / 40.8 19.7 39.5 7.9
E 0.138 0.068 0.107 0.313 4.1 21.7 34.2 9.3
F 0.121 0.062 0.121 0.304 39.8 20.4 39.8 9.4
SG 0.120 0.066 0.116 0.302 39.7 21.9 38.4 10.6
H 0.153 0.077 0.157 0.387 39.5 19.9 40.6 11.9
I 0.143 0.077 0.149 0.369 38.7 20.9 40.4 17.0
J 0.097 0.078 0.108 0.283 34.3 27.6 38.1 18.0
K 0.075 0.079 0.104 0.258 29.1 30.6 40.3 18.1
L 0.093 0.068 0.116 0.277 .33.6 24.5 41.9 22.4
M o 0.096 0.056 0.103 0.255 37.6 22.0 40.4 5.9
SN 0.097 0.083 0.130 0.310 31.3 26.8 41.9 26.1
S0 0.076 0.079 0.116 0.271 28.0 29.2 42.8 26.5
SP 0.111 0.059 0.103 0.273 ? 40.7 21.6 37.7 8.0
Florida Citrus Experiment Station
and Florida Citrus Commission,
Lake Alfred, Florida, 523 10/12/54-AHR








TABLE 2
Pectin and pectinesterase values in commercial samples from a plant manufacturing frozen
concentrated orange juices indicating partial enzymic inactivation
Pectin as anhydrogalacturonic acid g./l00 g. cone. Percentage of total pectin (PE.u.)g.
Sample soluble in soluble in reconstituted
H20 (NH4)2C204 NaOH Total H20 (NH4)2C204 NaOH juice X 104

1 0.118 0.047 0.122 0.287 41.1 16.4 42.5 8.3
2 0.1140.047 0.133 0.294 38.8 16.0 45.2 6.7
3 0.110 0.056 0.109 0.275 40.0 20.4 39.6 6.7
4 0.127 0.052 0.115 0.294 43.2 17.7 39.1 6.1
5 0.126 0.054 0.086 0.266 47.4 20.3 32.3 4.4
6 0.115 0.060 0.093 0.268 4_2.9_ 22._ 34.7 9.0
7 0.109 0.053 0.103 0.269 41.1 20.0 38.9 4.2
8 0.123 .0.058 0.111 0.292 4212.1 19.9 38.0| 5.5
9 0.097 0.059 0.101 0.257 37.7 23.0 39.3 6.4 t
ii725 .9 6.65
S10 0.101 0.058 0.108 0.267 37.9 21.7 40.4 6.6
11 0.112 0.057 0.101 0.270 41.5 21.1 39.1 7.4
12 i 0.097 0.055 0.094 0.246 39.4 22.4 38.2 8.7 ,
1 Samples collected semimonthly for six months from January through June 1954.
Florida Citrus Experiment Station
and Florida Citrus Commission,
Lake Alfred, Florida. 523a 10/12/54-AHR









Pectin and


TABLE 3
pectinesterase values in commercial samples from a plant manufacturing frozen
concentrated orange juices indicating no enzymic inactivation


Pectin as anhydrogalacturonic acid g./l00 g. cone. Percentage of total pectin (P.u.)g.
i Samplel soluble in soluble in reconstituted
H20 (NH4 )2C204 NaOH Total H20 (NH4)2C204 NaOH juice X 104
1 0.041 0.075 0.130 0.246 16.7 30.5 52.8 20.6
2 0.087 0.087 0.161 0.335 26.0 26.0 48.0 33.0
3 0.060 0.100 0.139 0.299 20.1 33.4 46.5 32.9
4 0.086 0.081 0.125 0.292 29.5 27.7 42.8 27.4
5 0.061 0.096 0.083 0.240 25.4 40.0 34.6 28.2
6 0.089 0.064 0.091 0.244 36.5 26.2 37.3 31.0
S 7 0.084 0.069 0.088 0.241 34.9 28.6 36.5 19.6
8 0.083 0.068 0.102 0.253 32.8 26.9 40.3 20.5
S 9 0.067 0.086 0.114 0.267 25.1 32.2 42.7 24.2
10 0.079 0.089 0.150 0.318 24.8 28.0 47.2 1 25.2
11 0.093 0.072 0.103 0.268 34.7 26.9 38.4 27.2
12 0.079 0.068 0.104 0.251 : 31.5 27.1 41.4 28.0
1 Samples collected semimonthly for six months from January through June 1954.
Florida Citrus Experiment Station
and Florida Citrus Commission,
Lake Alfred, Florida. 523b 10/12/54 AHR









TABLE 4
Relationship of the pectic fractions to cloud and gel stability in commercial samples
of frozen concentrated orange juices
Percentage of total pectin Degree of clarification Degree of gelatin2 (PE.u.)g.
Sample soluble in 72 hr. 24 hr. 72 hr. 24 hr. econstituted
SH20 (H4) 2204 I Initial at 400F. at 80F. !Initial at 400F. at 80OF. I juice X 104
S 31.5 68.5 45-none 97-extreme 98-extreme 0-none 2-slight 2-slight 26.3
23 35.3 64.7 48-none 96-extreme 97-extreme O-none 1-very slight 1-very slight 20.6
3 37.2 62.8 69-none 95-extreme 97-extreme 0-none 2-slight 2-slight 18.4
4 37.5 62.5 64-none 97-extreme 98-extreme I 0-none 3-semi-gel 3-semi-gel 32.9
5 71.7 28.3 40-none 51-none 52-none I O-none 1-very slight 1-very slight 6.9
6 70.9 29.1 40-none 60-slight 83-definite 0-none 0-none 0-none 6.7
7 70.3 29.7 38-none 49-none 93-extreme 0-none 1-very slight 3-semi-gel 14.3
8 70.3 29.7 41-none 65-slight 74-definite 0-none 0-none 0-none 3.1
93 49.1 50.9 45-none 80-definite 96-extreme O-none 1-very slight 0-none 15.0
10 53.1 46.9 i49-none 94-extreme 98-extreme 0-none 3-semi-gel 3-semi-gel 17.6
11 50.0 50.0 46-none 76-definite 93-extreme 0-none 0-none 0-none 7.4
12 50.0 50.0 48-none 97-extreme 99-extreme 0-none 2-slight 2-slight 33.0
1 Clarification measured by percentage light transmission of centrifuged reconstituted juice using 10 mm. rectangular
cell in Lumetron colorimeter with filter No. 730. Degree of clarification: 0 59% = none; 60 69% = slight;
70 84% = definite; 85 100% = extreme.
2 Gelation: 0 = none; 1 = very slight; 2 = slight; 3 = semi-gel; 4 = solid gel.
3 Combined water- and ammonium oxalate-soluble pectin less than 0.130 g./l00 g. concentrate.
Florida Citrus Experiment Station
and Florida Citrus Commission,
Lake Alfred, Florida. 523c 10/12/54 AHR









TABLE 5
Characteristics of selected commercial samples of frozen concentrated orange juices
, ,, |H .ui


Sample
characteristics


Big e
ox
owes

i; es

Lowesi

o e

i hes

ig

owes

owe

Thick,


Water- Pectin as AGAI g./10Og.conc.


insol.
solids
i ^


;t PE.u. and i1.02
,e-sol. pectin!
;0.80
i.


soluble in
H20 (NH4)2C204 NaOH


0.115


0.142


Total


0.127 0.181 0.423


0.060 0.111 0.313


Degree of clarification


Initial


72 hr. 24 hr.
at 400F. at 800F.


Degree of gelation3


72 hr.
Initial at 40OF.


-i I .


43
none


41
none


97
extreme


99
extreme


0 4
none sol aid el


none solid vel solid el


65 74
s1iaht dAfinit


0 0
none none


st H20-sol. 1.28 0.210 0.097 0.227 0.534 38 46 92 0 2 2
)tal pectin none none extreme none slightslight
1 0.65 0.041 0.075 0.130 0.246 48 96 97 0 1 1
_1. pectin ____none extreme extreme none v. slight v. slight
; NaOH-sol. i0.64 0.048 0.071 0.087 0.206 84 93 94 0 1 0
?tal pectin I ___ definiteextreme extreme none v. slight none
st 0.92 0.192 0.081 0.232 0.505 38 49 93 0 1 3
;ol. pectin none none extreme none v. slight semi-ael
*atio oxalate- 0.64 0.051 0.111 0.135 0.297 45 97 98 i 0 2 2
1-sol. pectin none extreme extreme none slight slight
st !0.64 0.118 0.047 0.122 0.287 42 67 97 0 1 1 I
.e-sol. pectin none slight extreme none v. sliht v. slighti
Swater- 0.43 0.094 0.083 0.122 0.299 49 94 98 0 3 3
solids none extreme extreme none semi-ael semi-eel
high H20-and 0.98 0.166 0.080 0.210 0.456 37 50 91 0 1 1
alate-sol. none none extreme! none v. slight v. slight


Ln ydUrogalacturonic acid (AGA).
2 Clarification measured by percentage light transmission of centrifuged reconstituted juice using 10 mm. rectangular cell
in Lumetron colorimeter with filter No. 730. Degree of clarification: 0-59% = none; 60-69% = slight; 70-84J = definite;
85-100% = extreme.
3 Gelation: 0 = none; 1 = very slight; 2 = slight; 3 = semi-gel; 4 = solid gel.
Florida Citrus Experiment Station and Florida Citrus Commission,
Lake Alfred, Florida. 523d 10/12/54 AHR


(PE.u. g.


24 hr.
at 800F.


4
solid Tel


0
nona


sconst,
juice


43.4


3.1



20.

.1

14.3

26.

8.3



7.2


t r


I I I I 1 1 I 1 1 I III I I I II


*







90 r


80 Fig. 1. Relationship of cloud to pectin in reconstituted
centrifuged juices prepared from commercial
frozen concentrated orange juices.



70

H

60- \


0 \





S,0
050








3I 0 I

10 20 30 40 50
PECTIN -- mg./100 g.










25


Fig. 2. Relationship of relative viscosity to pectin in
F reconstituted centrifuged juices prepared from
commercial frozen concentrated orange juices.
2.0





1.5
I.5 0" 0






i


"Sa


0.5





0.0 V


PECTIN mg./l0 g.


`-.X-CUI`---~-l~rr--rll-------~r------ -~W ---- ----~-e -- -r-












TABIE 6


Amount of vacuum or pressure in cans -- 221 frozen concentrated
orange juices from 23 Florida plants for the 1953-54 season

Number Number
Vacuum of % Total Pressure of % Total
samples samples
in. lbs,
21 1 0.4 0 3 1.4
20 1 0.4 1.0 4 1.8
19 3 1.4 1.5 1 0.4
18 1 0.4 2.0 9 4.1
17 3 1.4 2.5 1 0.4
16 6 2.7 3.0 29 13.1
15 14 6.3 3.5 2 0.9
14 5 2.3 4.0 9 4.1
13 6 2.7 8.0 1 0.4
12 9 4.1
11 7 3.2
10 18 8.1
9 4 1.8
8 13 5.9
7 10 4.5
6 7 3.2
5 18 8.1
4 9 4.1
3 10 4.5
2 9 4.1
1 2 0.9
0.5 6 2.7


Florida Citrus Experiment Station and
Florida Citrus Commission, Lake Alfred, Fla.
523g-10/12/54- AHR
















Percentages of
-- 221 frozen


TABLE 7
pulp by volume in reconstituted juices (centrifugal method)
concentrated orange juices from 23 Florida plants for the
1953-54 season


Number
% Pulp of % Total
samples

4.5 1 0.4
5.0 2 0,9
5.5 5 2.3
6.0 33 14.9
6.5 34 15.4
7.0 23 10.4
7.5 35 15.8
8.0 36 16.3
8.5 20 9.0
9.0 11 5.0
9.5 4 1.8
10.0 5 2.3
10.5 4 1.8
11.0 3 1.4
11.5 2 0.9
12.0 2 0.9
12.5 1 0.4


Florida Citrus Experiment Station and
Florida Citrus Commission, Lake Alfred, Fla.
523h-10/12/54-AHR







TABIE 8
Comparison between pH values of concentrates and reconstituted juices --
221 frozen concentrated orange juices from 23 Florida plants for the
1953-54 season

Concentrates Reconstituted juices
Number Number
pH of % Total of % Total
samples samples

3.4 3 1.4 0 0
3.5 45 20.4 1 0.4
3.6 128 57.9 5 2.3
3.7 43 19.4 97 43.9
3.8 2 0.9 99 44.8
3.9 0 0 19 8.6


TABLE 9
Degree of gelation after storage for 24 hours at 80 F. -- 221 frozen
concentrated orange juices from 23 Florida plants for the 1953-54
season1

Number
Degree of gelation of % Total
samples

0 (none) 126 57.0
1 (very slight) 64 29.0
2 (slight) 19 8.6
3 semi-gel) 11 5.0
4 (solid gel) 1 0.4

1No samples showed initial gelation









Florida Citrus Experiment Station and
Florida Citrus Commission, Lake Alfred, Fla.
523i-10/12/54-AHR







TABLE 10
Comparison between degree of clarification initially and after storage
for 24 hours at 800F. --- 221 frozen concentrated orange juices from
23 Florida plants for the 1953-54 seasonI

Initial 2 4 hours at 800CF
Number Number
Degree of of of
clarification samples % Total samples % Total
0-59 (none) 217 98.2 43 19.5
60-69 (slight) 3 1.4 16 7.2
70-84 (definite) 1 0.4 32 14.5
85-100 (extreme) 0 0 130 58.8

1 Clarification measured by percentage light transmission of
centrifuged reconstituted juice using 10 mm. rectangular
cell in Lumetron colorimeter with filter No. 730.




TABLE 11
Comparison between degree of gelation after storage for 72 hours at 400F.
and 24 hours at 800F. --- 160 selected frozen concentrated orange juices
from Florida plants for the 1953-54 season 1
72 hours at 400F. 24 hours at 800F.
Number Number
of of
Degree of gelation samples % Total samples % Total
0 (none) 49 30.6 70 43.7
1 (very slight) 79 49.4 60 37.5
2 (slight) 27 16.9 18 11.3
3 (semi-gel) 4 2.5 11 6.9
4 (solid gel) 1 0.6 1 0.6


These samples were selected
extreme clarification after
(see Table 10).


because they showed definite or
storage for 24 hours at 800F.


Florida Citrus Experiment Station and
Florida Citrus Commission, Lake Alfred, Fla.
523j 10/12/54 AHR









TABLE 12
Comparison between degree of clarification after storage for 72 hours at
400F. and 24 hours at 800F. --- 160 selected frozen concentrated orange
juices from Florida plants for the 1953-54 season 1s 2
72 hours at 400F. 24 hours at 80oF.
Number Number
Degree of of of
clarification samples % Total samples % Total
0-59 (none) 39 24.4 0 0
60-69 (slight) 26 16.2 0 0
70-84 (definite) 36 22.5 32 20.0
85-100 (extreme) 59 36.9 128 80.0
1 Clarification measured by percentage light transmission of
centrifuged reconstituted juice using 10 mm. rectangular
cell in Lumetron colorimeter with filter No. 730.
2 These samples were selected because they showed definite or
extreme clarification after storage for 24 hours at 800F.
(see Table 10).


























Florida Citrus Experiment Station and
Florida Citrus Commission, Lake Alfred, Fla.
523k 10/12/54 AHR




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