• 食品工程 •

### 超声处理对牛乳酪蛋白结构及抗原性的影响

1. （1.陕西科技大学食品与生物工程学院，陕西 西安 710021；2.陕西科技大学轻工科学与工程学院，陕西 西安 710021）
• 出版日期:2019-12-15 发布日期:2019-12-24
• 基金资助:
国家自然科学基金青年科学基金项目（31301405）；陕西省科技统筹计划项目（2013KTZB02-05（2））； 陕西省教育厅服务地方专项项目（19JC05）；西安市科技计划农业科技创新工程项目（20193035YF023NS023）

### Effect of Ultrasonic Treatment on the Structure and Antigenicity of Bovine Caseins

XUE Haiyan, CAO Ge, HE Baoyuan, FAN Jiaojiao, XUE Lihuan

1. (1. School of Food and Biological Engineering, Shaanxi University of Science and Technology, Xi’an 710021, China;2. College of Bioresources Chemical and Materials Engineering, Shaanxi University of Science and Technology, Xi’an 710021, China)
• Online:2019-12-15 Published:2019-12-24

Abstract: In this study, changes in the structure and antigenicity of the milk allergenic proteins α-casein (α-CN) and β-casein (β-CN) after ultrasonic treatment were investigated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, circular dichroism (CD) spectroscopy, fluorescence spectroscopy and enzyme-linked immunosorbent assay (ELISA). The results showed that with the increase of ultrasonic power, the molecular mass of α-CN did not change significantly, β-CN aggregated at 600 W; the carbonyl contents of the two caseins increased, and the free sulfhydryl contents decreased first and then rose after reaching a minimum value at 500 W, while the trend was opposite to that of hydrophobicity. The proportion of α-helical secondary structure was reduced after sonication, and the proportion of random coil initially increased with ultrasonic power up to 500 W and then decreased; this trend was opposite to that of β-sheet content, indicating that ultrasonic treatment could destroy the structure of casein. As the ultrasonic power increased, the antigenicity first increased, reaching a maximum level at 500 W, and then decreased. The hydrophobicity of caseins was positively correlated with changes in random coil content, but negatively correlated with changes in β-sheet content. Sonication could affect protein structure conformation while altering the antigenicity of caseins, which was associated with changes in hydrophobicity and random coil content.