The aggregation of raw goat milk under the different heat sterilization treatments was investigated based on protein structure and interaction. With the increasing heating temperature, the average particle size of goat casein micelles increased from 209.6 nm to 289.2 nm, and the range of particle size distribution increased as well. Under the ultra-high temperature treatment at 121 ℃ for 4 s, the particle size significantly enlarged due to the denaturation and aggregation of whey protein on the surface of casein micelles. Fourier infrared chromatographic scanning results showed that heat treatment conditions could result in a red shift of absorption peaks of goat milk to lower wavenumbers, suggesting that the hydrogen bonds of protein molecules were broken and re-associated. The secondary conformation of milk proteins was analyzed by amide I and amide III. The content of coils was significantly increased and the hydrophobic regions were turned out, causing changes in the spatial structure of goat milk protein. β-lactoglobulin played an important role in the binding of casein micelles with other whey proteins evidenced by SDS-PAGE gel electrophoresis analysis. This study investigated the changes in milk stability and protein structure by different heat sterilization methods to provide a theoretical reference for the effect of heat sterilization methods on protein in liquid goat milk production.
XUE Haiyan
,
LI Jingying
,
ZHAO Xianhui
,
HE Baoyuan
,
YI Meixia
,
SONG Hongxin
. Analysis of thermal aggregation in goat milk based on protein structure and interaction[J]. Food and Fermentation Industries, 2023
, 49(3)
: 175
-181
.
DOI: 10.13995/j.cnki.11-1802/ts.030009
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