Group Title: Citrus Station mimeo report ; 54-2
Title: Time-temperature relationships for heat inactivation of pectinesterase in citrus juices
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Permanent Link: http://ufdc.ufl.edu/UF00072348/00001
 Material Information
Title: Time-temperature relationships for heat inactivation of pectinesterase in citrus juices
Series Title: Citrus Station mimeo report
Physical Description: 6 leaves : ; 28 cm.
Language: English
Creator: Atkins, C. D
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: Citrus juices -- Composition -- Florida   ( lcsh )
Pectin -- Florida   ( lcsh )
Fruit juices -- Pasteurization -- Florida   ( lcsh )
Genre: government publication (state, provincial, terriorial, dependent)   ( marcgt )
non-fiction   ( marcgt )
 Notes
Statement of Responsibility: C.D. Atkins and A.H. Rouse.
General Note: Caption title.
 Record Information
Bibliographic ID: UF00072348
Volume ID: VID00001
Source Institution: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: oclc - 74132310

Full Text


Time-Temperature Relationships for Heat Inactivation of Pectinesterase
in Citrus Juices a
C. D. Atkins and A. H. Rouse

This investigation was concerned with the determination of time-temperature
relationships for inactivation of pectinesterase in citrus juices at'several pH
levels when retained in the pasteurizer for 0.8, 3, 6, and 12 seconds. Parson
Brown, Pineapple, and Valencia orange juices were prepared to contain 8% pulp by
volume and pH levels of 3.5 and 4.1, whereas Duncan grapefruit juice contained 8%
pulp by volume and pH 3.3 and 3.8. Dancy tangerine juice contained 10% pulp by
volume and pH 3.8.

The juices used in this investigation were prepared by extracting the juice,
pulp, and seeds with moderate pressure using a Rotary juice press. The seeds were
separated by a rotating reel and the juice finished in a Food Machinery, Model 35,
finisher with a 0.030 inch perforated screen to yield a juice of 8% and 10% pulp
by volume as preferred. The finished Juices were deaerated and cooled in an am-
monia-jacketed deaerator with the juices exposed to a vacuum of 27 inches for one
hour during the cooling process. The juices were then poured into 10 gallon drums
and stored at -SoF, until needed. Prior to heat treatment tests the juices were
thawed and passed through a Well turbine pump to obtain a homogenous mixture of
juice and pulp satisfactory for the tests. Because of the grinding action of the
pump the juices reached a temperature of 1000F., however, they were immediately
cooled to room temperature.
The pasteurizer used in these tests contained three hating coils of 1/8 inch
I.D., and one coil of 1/16 inch I.D. stainl ess steel tubing.\ Hot water was circu-
lated around the heating coils. The flow rate was adjus ed in each tube to 560 ml.
per minute. The juices were in contact i hea the 1/8 inch tubes for 12, 6,
and 3 seconds and in the 1/16 inch tube fsi,8 second; th4so times being required
to raise the juices from room temperature bhe desiredtemperature. All temper-
atures were controlled by a Brown potentioaeteirpyraoeter and checked constantly
with a Bureau of Standards thermometer.

Time-temperature relationships for heat inactivation of pectinesterase in
Parson Brown, Valencia, and Pineapple orange juices; Duncan grapefruit juice; Dan-
cy tangerine juice are presented in Tables 1, 2, 3, 4, and 5, respectively. Com-
plete inactivation of the enzyme in Parson Brown juice, pH 3.5, was obtained at
195 F., 2000F., 2050F., and 2050F. when retention times in the pasteurizer were 12,
6, 3, and 0.8 seconds, respectively, whereas the inactivation temperatures for this
juice, pH 4.1, were 2000F., 2050F., 210oF., and 2100?. for the above mentioned re-
tention times. Valencia and Pineapple orange juices, pH 3.5, when heated for 12, 6,
3, and 0.8 seconds were completely inactivated of pectinesterase at 1900F., 195F.,
2000F., and 2050F., respectively, while these juices, pH 4.1, were inactivated at
either 2050F. or 2100F. with these holding times. Duncan grapefruit juices at pH
3.3 and 3.8 when heated for 12 seconds required 1900F. and 195F., for 6 seconds
1950F. and 2000F., for 3 and 0.8 seconds 2000F. and 2050F. for complete inactiva-
tion of the enzyme. Dancy tangerine juices, pH 3.8, when heated for 12, 6, 3, and
0.8 seconds at 1950F., 2000F., 205oF., and 2100F., respectively, were completely
inactivated.
Any partial inactivation of the enzyme in these five varieties of citrus
juices at several pH levels can be obtained from the tables.

a American Can Company cooperating through the establishment of a grant-in-aid.
Citrus Station Mimeo Report 54-2. Florida Citrus Experiment Station and Florida
Citrus Commission, Lake Alfred, Florida. 461 10/6/53-CDA










TABIE I


Time-temperature relationships for heat inactivation of pectinesterase in Parson
Brown orange juice, pH 3.5 and 4.1


Holding Time 12 seconds 6 seconds 3 seconds 0.8 second
Inactivation Inactivation Inactivation Inactivation
Temperature pH 3.5 pH 4.1 pH 3.5 pH 4.1 pH 3.5 pH 4.1 pH 3.5 pH 4.1
OF. C. % % % % % % %
125 51.5 12.8 8.3 5.4 2.9 1.9 0.0 0.0 0.0
135 57.0 44.7 13.6 27.0 11.4 13.1 8.8 4.9 3.2
145 63.0 83.8 34.8 70.2 23.6 46.3 16.0 33.8 11.0
155 68.5 89.4 70.2 83.8 54.5 80.1 31.7 76.0 24.3
165 74.0 91.6 89.0 89.6 81.6 89.0 68.1 87.6 63.2
175 79.5 93.1 92.7 91.0 90.8 90.7 89.0 90..5 86.5
185 85.0 96.6 93.9 93.1 92.7 92.9 92.1 91.3 90.8
190 88.0 98.6 95.7 94.5 94.0 94.3 94.0 92.8 92.7
195 90.5 160.0 97.0 97.9 97.0 97.9 95.2 95.0 93.9
200 93.5 100.0 100.0 98.1 98.6 97.0 98.6 95.7
205 96.0 100.0 100.0 98.8 100.0 97.0
210 99.0 -- -- --- -- 100.0 100.0

Citrus Station Mimeo Report 54-2.
Florida Citrus Experiment Station
and Florida Citrus Commission,
Lake Alfred, Florida
429c 6/5/53 AHR











TABLE 2


Time-temperature relationships for heat inactivation of. pectinesterase in Valencia
orange juice, pH 3.5 and 4.1


Holding Time 12 seconds 6 seconds 3 seconds 0.8 second
Inactivation Inactivation Inactivation Inactivation
Temperature PH H3.5 pH 4.1 pH 3.5 pH4.1 H3.5 pH 4.1 pH 3.5 pH 4.1

125 ... 51.5 7.5 3.9 4.3 1.0 1.1 0.0 0.0 0.0
135 57.0 33.0 8.7 20.2 2.9 4.3 0.0 3.3 0.0
145 63.0 77.7 14.4 58.5 8.7 34.0 4.3 23.9 0.9
155 68.5 81.9 43.3 77.7 19.2 74.5 7.8 71.7 5.6
165 74.0 90.4 77.9 90.2 59.6 90.2 37.9 89.1 31.8
175 79.5 94.7 90.4 93.6 84.6 92.6 72.4 90.2 71.0
185 85.0 97.9 93.3 94.7 91.4 93.6 87.9 93.5 87.9
190 88.0 100.0 95.2 96.8 93.3 95.7 91.4 94.6 90.7
195 90.5 96.2 100.0 95.2 98.9 92.2 95.7 91.6
200 93.5 99.0 98.1 100.0 95.7 98.9 95.3
205 96.0 100.0 99.0 98.3 100.0 98.1
210 99.0 --- 100.0 100.0 100.0

Citrus Station limeo Report 54-2.
Florida Citrus Experiment Station
and Florida Citrus Commission,
LaE Alfred, Florida
429d 6/553 AHR










TABAI 3


Time-temperature relationships for heat inactivation of
orange juice, pH 3.5 and


pectinesterase in Pineapple
4.1


Holding Time 12:seconds 6 seconds 3 seconds 0.8 second
Inactivation Inactivation Inactivation Inactivation
Temperature pH 3.5 pH 4.1 pH 3.5 pH 4.1 pH 3.5 pH 4.1 pH 3.5 pH 4.1
OF. oC.. % % % % % % % %
125 51.5 16.7 5.3 8.8 0.0 3.9 0.0 1.0 0.0
135 57.0 49.0 11.5 28.4 7.1 16.7 0.0 13.7 0.0
145 63.0 88.2 31.9 77.5 23.9 57.8 15.0 45.1 9.7
155 68.5 90.2 71.7 89.2 53.1 88.2 35.4 85.8 31.9
165 74.0 93.1 87.6 92.2 80.5 90.2 69.0 89.2 62.0
175 79.0 94.1 90.3 93.1 89.4 92.2 86.7 92.2 85.0
185 85.0 98.0 92.9 94.1 91.2 94.1 90.8 93.6 87.6
190 88.0 100.0 94.7 98.0 92.9 96.1 91.5 94.5 90.8
195 90.5 96.5 100.0 94.7 98.0 94.3 96.1 91.5
200 93.5 98.2 98.2 100.0 95.0 98.0 94.7
205 96.0 100.0 -000- 98.2 100.0 98.2
210 99.0 -- -- -- 100.0 100.0

Citrus Station Mimeo Report 54-2.
Florida Citrus Experiment Station
and Florida Citrus Commission,
Lake Alfred, Florida
429e 6/5/53 AHR










TABIE 4


Time-temperature relationships for heat inactivation of pectinesterase in Duncan grape-
fruit juice, pH 3.3 and 3.8


Holding Time 12 seconds 6 seconds 3 seconds 0.8 second
Inactivation Inactivation Inactivation Inactivation
Temperature pH 3.3 pH 3.8 pH 3.3 pH 3.8 pH 3.3 pH 3,8 pH 3.3 pH 3.8
OF, .. % % % % % % %. %
125 51.5 48.7 22.0 40.7 17.2 36.7 0.0 28.0 0.0
135 57.0 78.8 28.3 64.3 22.8 55.2 1.6 45.0 0.0
145 63.0 82.7 72.1 82.0 32.3 80.4 18.8 77.2 13.1
15-5 68.5 88.1 82.6 $6.8 76.4 85.3 55.8 84.5 45.2
165 74.0 89.9 86.7 88.8 84.4 86.9 81.7 86.1 75.9
175 79.5 93.9 90.7 92.4 90.7 90.1 86.0 88.5 84.1
185 85.0 96.2 94.6 93.9 92.3 92.4 88.5 90.9 86.6
190 88.0 100.0 97.7 97.7 96.1 94.7 92.4 94.0 89.8
195 90.5 100.0 100.0 98.4 98.5 96.2 97.8 92.2
200 93.5 -- 100.0 100.0 98.4 100.0 96.1
205 96.0 -- -- -- 100.0 100.0


Citrus Station 1Mimeo Report 54-2.
Florida Citrus Experiment Station
and Florida Citrus Commission,
Lake Alfred, Florida
429f 6/5/53 AHR











TABLE 5


Time-temperature relationships for heat inactivation of
Dancy tangerine juice, pH 3.8


pectinesterase in


Citrus Station Mimeo Report 54-2.
Florida Citrus Experiment Station
and Florida Citrus Commission,
Lake Alfred, Florida
429g 6/5/53 AHR


Holding time 12 seconds 6 seconds 3 seconds 0.8 second
Inactivation Inactivation Inactivation Inactivation
Temperature pH 3.8_ H 3.8 pH 3.8 pH 3. pH 3
OF. oc. % % %
125 51.5 18.1 16.4 13.0 6.1
135 57.0 31.7 24.0 20.5 7.2
145 63.0 57.7 44.4 35.2 24.6
155 68.5 74.1 64.2 57.7 51.2
165 74.0 80.6 75.8 74.1 70.7
175 579.5 84.0 80.6 78.5 74.1
185 85.0 87.4 84.0 81.6 77.5
190 88.0 93.5 90.4 86.7 80.6
195 90.5 100o. 93.5 92.2 84.0
200 93.5 100.0 93.9 90.4
205 96.0 100.0 93.5
210 99.0 -- -- 100.0




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