Enzymatic Hydrolysis of Heat-Induced Aggregates of Whey Protein Isolate
I.B. O’Loughlin, Brian A. Murray, Phil Kelly, Richard J. Fitzgerald, André Brodkorb
Journal of Agricultural and Food Chemistry
Abstract
The effects of heat-induced denaturation and subsequent aggregation of whey protein isolate (WPI) solutions on the rate of enzymatic hydrolysis was investigated. Both heated (60 °C, 15 min; 65 °C, 5 and 15 min; 70 °C, 5 and 15 min, 75 °C, 5 and 15 min; 80 °C, 10 min) and unheated WPI solutions (100 g L(-1) protein) were incubated with a commercial proteolytic enzyme preparation, Corolase PP, until they reached a target degree of hydrolysis (DH) of 5%. WPI solutions on heating were characterized by large aggregate formation, higher viscosity, and surface hydrophobicity and hydrolyzed more rapidly (P < 0.001) than the unheated. The whey proteins exhibited differences in their susceptibility to hydrolysis. Both viscosity and surface hydrophobicity along with insolubility declined as hydrolysis progressed. However, microstructural changes observed by light and confocal laser scanning microscopy (CLSM) provided insights to suggest that aggregate size and porosity may be complementary to denaturation in promoting faster enzymatic hydrolysis. This could be clearly observed in the course of aggregate disintegration, gel network breakdown, and improved solution clarification.
Extracted Claims
4 claims extracted from this paper into the knowledge graph
enzymatic hydrolysis affected by heat-induced denaturation and subsequent aggregation of whey protein isolate
“The effects of heat-induced denaturation and subsequent aggregation of whey protein isolate (WPI) solutions on the rate of enzymatic hydrolysis was investigated.”
hydrolysis progressed viscosity and surface hydrophobicity along with insolubility declined
“Both viscosity and surface hydrophobicity along with insolubility declined as hydrolysis progressed.”
aggregate size and porosity complementary to denaturation in promoting faster enzymatic hydrolysis
“microstructural changes observed by light and confocal laser scanning microscopy (CLSM) provided insights to suggest that aggregate size and porosity may be complementary to denaturation in promoting ...”