超高压对酱卤羊肚感官品质、微观结构及其肌浆蛋白特性的影响

以真空包装酱卤羊肚为研究对象，通过单因素试验探讨超高压（ultra high pressure，UHP）处理对酱卤羊肚感官品质的影响；采用压力水平100、250、400 MPa，保压时间5、10、15、20、25 min，保压温度25 ℃的条件进行UHP处理，通过双缩脲法、圆二色光谱、扫描电子显微镜观察及肌浆蛋白的物化指标分析，研究UHP对酱卤羊肚微观结构及肌浆蛋白特性的影响。结果表明：不同条件的UHP处理导致酱卤羊肚的感官品质差异明显，UHP处理使酱卤羊肚肌浆蛋白的内部基团暴露于分子表面，导致蛋白质的二级结构发生改变，较稳定的α-螺旋含量增加，β-折叠含量降低，而不规则的β-转角和无规卷曲含量无明显变化；羰基含量、表面疏水性和浊度增加，总巯基含量、游离氨基比例、溶解性减小，400 MPa、25 ℃ UHP处理20 min可使肌浆蛋白发生适度的氧化变性，导致酱卤羊肚的微观结构发生改变，最终使产品的感官品质得到改善。

Effect of Ultra High Pressure on Sensory Quality,Microstructure and Sarcoplasmic Protein Properties of Sauced Sheep Stomach

In this paper, vacuum packaged sauced sheep stomach was used to evaluate its sensory quality as affected by ultra high pressure (UHP) treatment. UHP treatments were carried out under varying conditions of pressure (100, 250 and 400 MPa) and holding time (5, 10, 15, 20 and 25 min) and at a constant temperature of 25 ℃. The physicochemical and functional properties and sarcoplasmic protein characteristics were studied by the biuret method, circular dichroism spectroscopy and scanning electron microscopy in order to investigate the effect of UHP on the microstructure and sarcoplasmic protein characteristics of sauced sheep stomach. The results showed that sensory quality significantly differentiated between UHP-treated and untreated samples. UHP treatment led to exposure of internal groups on the protein surface and alterations in the protein secondary structure. After the treatment, the contents of the stable secondary structures α-helix and β-sheet increased and decreased respectively, while the contents of irregular β-turn and random coil did not significantly change. In addition, UHP treatment caused an increase in carbonyl content, surface hydrophobicity and turbidity, and a decrease in total sulfhydryl content, free ammonia content and solubility. UHP treatment under 400 MPa and 25 ℃ for 20 min could cause moderate oxidative denaturation of sarcoplasmic protein, changes in the microstructure, and eventually improve the sensory quality of sauced sheep stomach.