Group Title: Citrus Station mimeo report - Florida Citrus Experiment Station ; 54-4
Title: Characteristics of citrus concentrates prepared from juices heated at various temperatures prior to concentration
CITATION PAGE IMAGE ZOOMABLE
Full Citation
STANDARD VIEW MARC VIEW
Permanent Link: http://ufdc.ufl.edu/UF00072349/00001
 Material Information
Title: Characteristics of citrus concentrates prepared from juices heated at various temperatures prior to concentration
Series Title: Citrus Station mimeo report
Physical Description: 10 leaves : ; 28 cm.
Language: English
Creator: Rouse, A. H
Atkins, C. D
Huggart, R. L
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: Fruit juices -- Processing -- Florida   ( lcsh )
Frozen concentrated fruit juice industry -- Florida   ( lcsh )
Pectin -- Florida   ( lcsh )
Genre: government publication (state, provincial, terriorial, dependent)   ( marcgt )
non-fiction   ( marcgt )
 Notes
Statement of Responsibility: A.H. Rouse, C.D. Atkins, and R.L. Huggart.
General Note: Caption title.
 Record Information
Bibliographic ID: UF00072349
Volume ID: VID00001
Source Institution: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: oclc - 74140024

Full Text



Characteristics of Citrus Concentrates Prepared from Juices Heated at
Various Temperatures prior to Concentration*
A. H. Rouse, C. D. Atkins, and R. L. Huggart


This investigation was concerned with the effect of heat treatment on pectin-
esterase activity and changes in pectic substances during processing and short-
term storage of 420Brix Parson Brown, Pineapple, and Valencia orange and Dancy
tangerine concentrates. Data are also presented to show clarification, gelation,
and flavor ratings of the 420Brix concentrates.

Concentrates were prepared as shown in Table 1 from unheated and heated juices
of oranges and tangerines. The extracted juice frca the Rotary press was passed
through a revolving 1/4 inch screen to remove seeds and coarse particles of pulp
and finished through a 0.030 inch screen. resulting in a juice with a pulp content
from 8 to 10% by volume. The cut-back juice was prepared by refinishing the pulpy
residue through a 1/8 inch screen, which resulted in a cut-back juice ranging in
pulp content from 25 to 50% by volume.

Juice to the evaporator was pumped through 24 feet of 1/8 inch I.D. stainless
steel tubing at a flow rate of 560 rl./cin. Hot water was circulated around the
heating coil to provide the desired temperaturethat w'old result in approximately
0, 75, 90, and 100% inactivation of pectines 6I'se in the s gle-strength juice.
The time required to heat the juice from ro~t temperature 'tc\he desired tempera-
ture was six seconds. The juice was dischaged directly from the heater through
44 feet of 1/8 inch I.D. stainless steel c aoing coigrequiirg 14.2 seconds to
cool the heated juice to a temperature between 8O and 86OF,. The control juice
was run' through the same equipment but with6t 'at. Thejuice was then flashed
into the evaporator, concentrated to 55Brix, cut-back toZ OBrix with unheated
out-back juice, packed in 6-oz. cans, and stored at -8IF.

Changes in pectic substances during the processing of unheated and heated
juices are shown in Tables 2 and 3. A typical example of these changes in an un-
heated juice is presented in Table 2 in which the water-soluble fraction decreased
from 0.064 to 0.054%, whereas the polyphosphate-soluble fraction increased from
0.103 to 0.121%. This is approximately a 16% change. Juices heated to 155, 175,
and 2050F. lost no water-soluble pectin during evaporation to 55Brix. Percentages
of total pectin-as water, polyphosphate, and sodium hydroxide-soluble are presented
in Table 3 for 4 controls and 12 juices heated to various temperatures and concen-
trated to 550Brix. Except for the Dancy tangerine concentrate, the water-soluble
decreased and the polyphosphate-soluble increased in the control samples, while
the pectic substances in those heated remained constant. No hydrolysis of proto-
pectin was found during processing of these four varieties of juices.

Changes in pectinesterase activity during heat treatment and processing are
presented in Table 4. Loss of activity during concentration to 550Brix of the un-
heated juices varied from 6.8 to 22.8%.
Samples of 42OBrix concentrates were removed from -80F. storage and placed
at 800F. storage for 24 hours, Data presented in Table 5 show a decrease in water-
soluble and an increase in polyphosphate-soluble pectin in the unheated samples,

SAmerican Can Company cooperating through the establishment of a grant-in-aid,
Citrus Station Mimeo Report 54-4. Florida Citrus Experiment Station and Florida
Citrus Commission, Lake Alfred, Florida. 468 10/6/53 AHR







whereas pectic fractions in the juices heated prior to concentration remained fair-
ly constant during the short-term storage period except in the Parson Brown concen-
trates. There were no indications of protopectin hydrolysis in these samples dur-
ing storage.

Pectinesterase activity changes in 420Brix concentrates during short-term
storage are shown in Table 6. The loss in activity ranged from 4.3 to 41.4%.

Data showing the water and polyphosphate-soluble pectin as anhydrogalacturonic
acid per 100 grams of concentrate and clarification and gelation initially and after
storage are presented in Table 7. There were no significant changes of the pectic
substances in most of the heated samples during storage and therefore neither cla-
rification nor gelation occurred in these samples. However, the control samples,
except the tangerine, did show significant changes in clarification after storage.

Flavor ratings on these packs initially and after 6 months storage at -80F.
are presented in Table 8. The Valencia pack has not been in storage for 6 months.
A small taste panel of 5 members are grading the samples of 42oBrix concentrates
over a period of 1 year. Since all of the initial grades of the reconstituted con-
centrates fell into the fair category, there was very little difference between
unheated and heated samples. Also apparently there was little change in flavor of
these samples after a storage period of 6 months.
























Citrus Station Mimeo Report 54-4. Florida'Citrus Experiment Station and Florida
Citrus Commission, Lake Alfred, Florida. 468a 10/6/53 AHR








TABLE 1
Outline showing the heat treatment, evaporation, and storage of 42OBrix citrus concentrates from which
samples were obtained for analyses


Dancy Tangerines
1 Juice 9.60Brix,


10% pulp, control


2 1500F. evaporated
------ 55OBrix
3 "n 190F. to


cut-back with
J-------- 42ored at
pulpy juice to stored at -80F.


samples
-----d
stored at


i .n n I 2000F.


Parson Brown Oranges
1 Juice 9.80Brix,


8% pulp, control


2 n 155F.

3 I" 1705F.
4 "1 If ,, it i 205?F.


evaporated
-----. 55Brix
to


cut-back with

pulpy juice to


420Brix
stored at -80F.


samples \

stored at


80F., 24 hrs.


Pineapple Oranges
1 Juice 12.8 Brix,


8% pulp, control


2 1550F.
3 it n i i 1750F.
4 I 2050F.
Valencia Oranges
1 Juice 12.6*Brix, 8% pulp, control
2 1550F.

3 n 1 n in 17.5 F.
4 i" 2050F.


evaporated
.----.-- 55Brix
to




evaporated
.-.. 550Brix
to


cut-back with

pulpy juice to




cut-back with

pulpy juice to


42OBrix
stored at -80F.





42oBrij
stored at -8F.


samples

stored at




samples

stored at


800F., 24 hrs.






80F., 24 hrs.


80F., 24 hrs.


Citrus Station Mimeo Report 54-4. Florida Citrus Experiment Station and Florida Citrus Commission,
Lake Alfred, Florida. 468b- 10/6/53 AHR













TABLE 2

Changes in pectic substances during evaporation of Valencia orange juices receiving
various heat treatments and then concentrated to 55Brix


Treatment of Pectin as anhydrogalacturonic acid extracted with
Juices and H20 (NaPO0)n NaOH Total
resulting wet dry wet dry wet dry wet dry
concentrates % % % % %
Juice to evaporator 0.008 0.064 0.013 0.1Q3 0.016 0.127 0.037 0.294
55)Brix cone., control 0.030 0.054 0.067 0.121 0.067 0.121 O.16h 0.296
t t 155O. 0.038 0.068 0.061 0.110 0.067 0.120 0.166 0.298
" 175 0.038 0.068 0.062 0.110 0.072 0.129 0.172 0.308
I i 2050$. 0.043 0.077 0.057 0.102 0.072 0.129 0.172 0.308

Citrus Station Mimeo Report 54L-. Florida Citrus Experiment Station and Florida Citrus
Commission, Lake Alfred, Florida. 468c-10/6/53 AHR











TABLE 3


Changes in pectic substances during the evaporation of citrus juices
heat treatment and then concentrated to 550Brix


receiving various


Variety and treatment Percentage of total pectin
of juices and H20-sol. (NaPO3)n-sol. NaOH-sol.
resulting concentrates ....
____ ,_. ._._... _______* ________0________a_____


Valencia oranges
Juice to evaporator
55 'rix conc., control
It t 155%.
I" 175 9c.
205 F.
Pineapple oranges
55'brix cone., control
it 11 it 155"F.
i" t 175 %.
I In I 205 ?.
Parson Brown oranges
55Brix cone., control
It It i 155 F.
I" 175 cF.
In n 205F.
Dancy tangerines
55-Br'ix cone., control
150%1.
i" 190 %.
It 1 200 c.


21.8
18.2
22.8
22.1
25.0

i7.0
1. 2
22.1
22.6

12.7
1A.3
17.1
16.9

50.8
49.2
51.0
49.0


35.0
40.9
36,9
36.0
33.1

44.3
39.7
35.6
35.0

35.8
34.4
29.8
27.1

23.7
23.5
21.9
20.9


L3.2
4o.9
40.3
41.9
41.9

38.7
39.1
42.3
42.4

51.5
51.3
53.1
56,0

25.5
27.3
27.1
30.1


Citrus Station Mimeo Report Sh-4.
Commission, late Alfred, Florida.


Florida Citrus
h68d-10/6/53 -


Experiment
AHR


Station and Florida Citrus












TABLE 4


Changes in pectinesterase activity during heat treatment and evaporation of citrus
juices to $55'rix


Variety and treatment PE activity Variety and treatment PE activity
of juices and per gram of Inactivation of juices and per gram of Inactivation
resulting concentrates soluble solids % resulting concentrates soluble solids %
x 1000a x 1000a
Valencia oranges Parson Brown oranges
Juice to evap., pH 3.7 10.1 0.0 Juice to evap., pH 4.0 11.7 0.0
55'Crix cone., control 7.8 22.8 55~rix cone., control 10.9 6.8
It I I 155$P. 1.2 88.1 t" 155-. 3.8 67.5
175 F. 0.8 92.1 i" 175 '. 0.9 92.3
I" 205$. 0.0 100.0 i 205F. 0.1 99.1

Pineapple oranges Dancy tangerines
Juice to evap., pH 3.7 9.9 0.0 Juice to evap., pH 3.8 2.9 0.0
55cBrix concon.,control 8.6 13.1 55rix cone., control 2.0 17.2
I 155F. 1.3 86.9 n" 150I 1.0 65.5
175 T. 0.6 93.9 190 0.3 89.7
i 205 O. 0.0 100.0 i" 200 0.05 98.3


a Soluble solids measured by refractometer at 28C. as 'rix.

Citrus Station Mimeo Report $Sh-. Florida Citrus Experiment Station and Florida Citrus Commission,
Lake Alfred, Florida. 468e-10/6/53 AHR








TABLE 5
Changes in pectic substances in 42 Brix citrus concentrates during short-term storage


Variety and Treatment Initial After 24 hours storage at 80'F.
of juices and Percentage of total pectin Percentage of total pectin
resulting concentrates H20-sol. (NaPO3)n-sol. NaOH-sol. H20-sol. (NaPO3 -sol. NaOH-sol.

Valencia oranges
42 Brix, control 15.2 37.3 47.5 9.8 43.2 47.0
t It 155 F. 17.3 36.0 46.7 15.7 36.8 47.5
I" 175 k. 17.8 35.9 46,3 15.6 37.2 47.2
*t 205 O. 18.6 35.1 46.3 18.1 33.4 48.5

Pineapple oranges
42 Brix, control 10.3 39.7 50.0 8.3 43.0 48.7
t 155'F. t14.7 36.0 49.3 13.0 39.6 47L.
175 F. 12.0 36.7 51.3 13.2 36.6 50.2
2050. 13.4 34.9 51.7 12.7 37.4 49.9

Parson Brown oranges
42 brix, control 10.9 35.6 53.5 7.4 42.6 506.
155 15.1 31.4 53.5 10.6 40.2 49.2
175 T. 14.8 31.2 5h.o 10.4 38.7 50.9
205 F. 17.5 29.2 53.3 12.8 35.7 51.5

Dancy tangerines
h2 crix, control 45.8 22.9 31.3 38.7 30.7 30.6
i" 150 h3.4 2L.0 32.6 44.0 25.8 30.2
190 F. 44.1 22.7 33.2 45.5 22.7 31.8
200 F. 41.7 22.7 35.6 42.3 23.4 34.3


Citrus Station Mimeo
Lake Alfred, Florida.


Report 54-4. Florida
468f-10/6/53 AHR


Citrus Experiment Station and Florida Citrus Commission,







TABLE 6


Changes in pectinesterase activity in 420Brix citrus concentrates during short-term storage


Initial After 24 hours storage at 800F.
Variety and treatment PE activity Inactivation PE activity Inactivation
of juices and per gram of per gram of
resulting concentrates soluble solids soluble solids
x 1000 % x 1000 b %
Valencia oranges
42OBrix, control 13.7 0.0 10.0 27.0
i" 1550F. 6.9 49.6 4.8 30.4
1750F. 6.1 55.5 4.2 31.1
2050F. 4.9 64.2 3.5 28.6
Pineapple oranges
42OBrix, control 13.9 0.0 11.3 18.7
1550F. 7.4 46.8 5.4 27.0
1750F. 6.3 54.7 4.8 23.8
2050F. 5.8 58.3 3.4 41.4
Parson Brown oranges
42Brix, control 15.8 0.0 13.4 15.2
1550F. 10.3 34.8 8.6 16.5
1750F. 6.6 58.2 5.8 12.1
2050F. 4.7 70.3 3.9 17.0
Dancy tangerines
42OBrix, control 4.1 0.0 2.7 34.1
1500F. 2.9 29.3 2.6 10.3
1900F. 2.3 13.9 2.2 4.3
S" 2000F. 1.7 58.5 1.4 17.6
b Soluble solids measured by refractometer at 2800. as OBrix.


Citrus Station Mimeo Report 54-4. Florida Citrus Experiment Station and
Lake Alfred, Florida. 468g-10/6/53 AHR


Florida Citrus Commission,






TABLE 7


Data showing


water and polyphosphate-soluble pectic fractions and clarification and gelation
in 42oBrix concentrates


Pectin as anhydrogalacturonic acid Degree of Degree of
Variety and treatment per 100 grams concentrate clarification c gelation
of juices and Initial After 24 hrs. 800F. Initial After 24 hrs. After 24 brs.
resulting concentrates 20sol. (NaPO3)n-sol. H20-sol. (NaPO3)n-sol. at 800F. at 800F.

Valencia oranges
42OBrix, control 0.025 0.061 0.016 0.071 63 slight 74 definite none
n" 1550F. 0.029 0.060 0.026 0.061 60 slight 62 slight none
175F. 0.030 0.061 0.026 0.062 62 slight 66 slight none
205F. 0.032 0.060 0.030 0.055 63 slight 64 slight none
Pineapple oranges
42OBrix, control 0.020 0.077 0.016 0.084 61 slight 82 definite very slight
n n 1550F. 0.028 0.068 0.025 0.076 .61 slight 67 slight very slight
n 1750F. 0.023 0.070 0.026 0.072 59 none 65 slight very slight
2050F. 0.026 0.068 0.025 0.074 63 slight 63 slight very slight
Parson Brown oranges
420Brix, control 0.024 0.078 0.016 0.091 49 none 87 extreme none
n 1550F. 0.032 0.067 0.023 0.087 51 none 51 none none
1750F. 0.032 0.068 0.022 0.083 51 none 51 none none
2050F. 0.037 0.062 0.028 0.078 54 none 54 none none
Dancy tangerines
42OBrix, control 0.088 0.044 0.078 0.062 42 none 55 none none
1500F. 0.080 0.044 0.087 0.051 43 none 47 none none
190F. 0.078 0.040 0.084 0.042 43 none 44 none none
2000F. 0.072 0.039 0.070 0.039 43 none 40 none none
c Clarification measured by percentage light transmission of centrifuged reconstituted lice ,sin It mm, ~~+
juceusn 0 aM rect,


cell in Lumetron colorimeter with Filter No. 730. Degree of clarification:
70 84% = definite; 85 100% = extreme.


0 59% = none; 60 69% = slight;


Citrus Station 4imeo Report 54-4. Florida Citrus Experiment Station and Florida Citrus Commission,
Lake Alfred, Florida. 468h-10/6/53 AHR








TABIE 8


Flavor ratings of citrus concentrates made from juices heated prior to concentration


Variety and treatment Average graded of taste panel
of juices and Initial After 6 months
resulting concentrates storage at -8F.

Valencia oranges
42OBrix, control 6 fair -- -
n n 1550F. 7 fair - -
n 1750F. 6 fair- -
n 2050F. 6 fair -
Pineapple oranges
42oBrix, control 7 fair 6 fair
1550F. 6 fair 7 fair
n i 1750F. 7 fair 6 fair
n 205F. 6 fair 7 fair
Parson Brown oranges
42oBrix, control 6 fair 6 fair
1550F. 5 fair 5 fair
1750F. 6 fair 6 fair
i" 205F. 5 fair 5 fair
Dancy tangerines
42OBrix, control 6 fair 7 fair
S" 1500?. 5 fair 7 fair
S" 1900F. 6 fair 8 good
2000F. 5 fair 7 fair

d Grade system: 10 = excellent; 9, 8 = good; 7, 6, 5 = fair; 4, 3, 2 = poor;
1 = objectionable.

Citrus Station Mineo Report 54-4. Florida Citrus Experiment Station and Florida
Citrus Commission, Lake Alfred, Florida. 4681-10/6/53 AHR




University of Florida Home Page
© 2004 - 2010 University of Florida George A. Smathers Libraries.
All rights reserved.

Acceptable Use, Copyright, and Disclaimer Statement
Last updated October 10, 2010 - - mvs