热加工处理羊乳α-酪蛋白（α-casein，α-CN）和β-酪蛋白（β-casein，β-CN），通过圆二色谱、荧光光谱等方法探索不同热加工条件下羊乳的蛋白结构变化与抗原性的关系。结果表明：随着对蛋白热处理温度的升高，会破坏羊α-CN和β-CN的天然结构，使得分子内部发生交联或聚集，导致分子量发生改变，分子内游离羰基含量升高，在134 ℃时，羰基含量分别增长了134.72%、110.98%；自由巯基含量则不断下降；疏水性探针检测最大荧光吸收强度分别增加了50.38%和9.61%，升温引起疏水基团或二硫键等被暴露出来，导致蛋白疏水性随着温度的升高而增大。圆二色谱显示，二级结构中卷曲程度或弹性结构发生复杂的转化，使蛋白质空间结构发生改变，α-螺旋呈现增加趋势，β-转角和无规则卷曲则在减少。两种蛋白的抗原性随着温度的升高而降低，经模拟胃肠消化，134 ℃处理后抗原性分别减少了80.63%和84.12%。故热处理可降低羊乳酪蛋白的抗原性，且抗原性变化与蛋白的游离羰基含量变化呈反比，还与二级结构中的无规则卷曲及β-转角含量呈正相关关系。

The heat treatment of α-casein (α-CN) and β-casein (β-CN) in goat milk was explored by circular dichroism, fluorescence spectroscopy and other methods to analyze the effects of their structure and antigenicity. The results showed that with the increase of the heat treatment temperature of the casein, the natural structure of α-CN and β-CN was destroyed, caused molecular cross-linking or aggregation, and changed the molecular weight. The content of free carbonyl in the molecule increased. At 134 ℃, the carbonyl content increased by 134.72% and 110.98%, respectively. The free sulfhydryl content decreased continuously. The maximum fluorescence absorption intensity of the hydrophobic probes increased by 50.38%, and 9.61%, respectively. The temperature rise caused hydrophobic groups or disulfide bonds to be exposed, resulting in increasing hydrophobicity of the proteins. Circular dichroism results showed that the degree of curl or elastic structure in the secondary structure undergoes complex transformation, which changes the spatial structure of the protein. α- spirals were increased, β- turns and irregular curls were decreased. The antigenicity of casein decreased with increased temperature. After simulated gastrointestinal digestion, the antigenicity was reduced by 80.63% and 84.12%, respectively, at 134 ℃. Therefore, heat treatment can reduce the antigenicity of goat milk casein. And the change of antigenicity are inversely proportional to the change of free carbonyl content of protein. In addition, it is also positively correlated with the content of irregular curls and β-turns in the secondary structure.

陕西省重点研发计划项目（2020ZDLNY02-09）；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（20193035YF023NS023，20NYYF0016）