Effect of Heat Treatment on the Property, Structure, and Aggregation of Skim Milk Proteins
Hongbo Li, Tingting Zhao, Hongjuan Li, Jinghua Yu
Frontiers in Nutrition
Abstract
To study the mechanism of heat-induced protein aggregates, skim milk was heated at 55, 65, 75, 85, and 95°C for 30 s. Then, the sulfhydryl content, surface hydrophobicity, and secondary structure of heat-treated skim milk were studied. Treating skim milk at different temperatures induced a decrease in sulfhydryl content (75.9% at 95°C) and an increase in surface hydrophobicity (44% at 95°C) with a disrupted secondary structure containing random coil, β-sheet, and β-turn of skim milk proteins. The change in these properties facilitated aggregate formation through disulfide bonds and hydrophobicity interaction. Microstructural observation also showed a higher degree of aggregation when skim milk was heated at 85 and 95°C. The result of two-dimensional polyacrylamide gel electrophoresis demonstrated that the aggregates consisted of a high proportion of κ-casein, β-lactoglobulin, and other whey proteins.
Extracted Claims
6 claims extracted from this paper into the knowledge graph
skim milk proteins facilitated aggregate formation
“The change in these properties facilitated aggregate formation through disulfide bonds and hydrophobicity interaction”
skim milk proteins formed aggregates
“The result of two-dimensional polyacrylamide gel electrophoresis demonstrated that the aggregates consisted of a high proportion of κ-casein, β-lactoglobulin, and other whey proteins”
skim milk proteins decreased sulfhydryl content
“Treating skim milk at different temperatures induced a decrease in sulfhydryl content (75.9% at 95°C)”