CA2-INDUCED COLD GELATION OF WHEY-PROTEIN ISOLATE - EFFECT OF 2-STAGEGELATION()

Citation
P. Hongsprabhas et S. Barbut, CA2-INDUCED COLD GELATION OF WHEY-PROTEIN ISOLATE - EFFECT OF 2-STAGEGELATION(), Food research international, 30(7), 1997, pp. 523-527
Citations number
25
Journal title
ISSN journal
09639969
Volume
30
Issue
7
Year of publication
1997
Pages
523 - 527
Database
ISI
SICI code
0963-9969(1997)30:7<523:CCGOWI>2.0.ZU;2-K
Abstract
The combined effect of a secondary heat treatment and CaCl2 level (5-1 20 mmol dm(-3)) on Ca2+-induced cold gelation of whey protein isolate (WPI) was investigated. Pre-heating was required to induce cold gelati on. Prolonging pre-heating time (30 to 60 min at 80 degrees C) increas ed gel clarity but had no effect on Young's modulus, shear stress and strain at failure and water holding capacity (WHC). Re-heating the col d-set gels at 80 degrees C for 30 min significantly (p less than or eq ual to 0.05) increased gel opacity, Young's modulus, stress and strain and decreased WHC. Scanning and transmission electron micrographs rev ealed that re-heating resulted in an increase in pore size and lowered the degree of protein strand connectivity. Overall, the second heatin g step changed the gel's properties due to increasing aggregation of t he calcium-induced cold-set gels. (C) 1998 Canadian Institute of Food Science and Technology. Published by Elsevier Science Ltd. All rights reserved.