大盘鸡炒炖加工过程中蛋白质降解和微观结构变化

Changes of proteolysis and microstructure of Dapanji during the stir-fried and stewed processing

目的:为大盘鸡的工艺改进及工业化标准化生产提供指导。方法:采用智能炒制机模拟传统炒炖工艺制作大盘鸡,用氨基酸分析仪对鸡肉炒炖加工过程中的游离氨基酸进行测定、用凯氏定氮法测定总氮和非蛋白氮的含量、用SDS-PAGE和扫描电镜对鸡肉炒炖加工过程中肌纤维蛋白降解及微观结构的改变进行了研究。结果:大盘鸡成品中游离氨基酸、必需氨基酸和呈味氨基酸的含量比原料鸡肉分别增加了48.63%,53.78%,55.78%,含量分别高达30.38,12.61,13.74 g/100 g;大盘鸡成品中总氮(TN)和非蛋白氮(NPN)含量比原料鸡肉均显著降低(P<0.05)。SDS-PAGE图谱显示,原料经炖炒阶段处理后加剧了分子量为97 kDa和分子量为15~25 kDa的蛋白的降解;炒制和炖炒过程中鸡肉的肌球蛋白重链发生降解并形成分子量为47,55,60 kDa的降解产物。经扫描电镜结构表征,与炒制后的半成品相比,炖炒加工后鸡肉肌膜发生可见溶解,肌纤维组织结构紧实。结论:应用智能炒制机制作大盘鸡,不但可以保持传统感官品质和风味,而且可以缩短加工时间,提高工作效率。

Objective:It was expected to provide guidance for the improvement of production technology and standardization of industrial production of dapanji.Methods:The intelligent frying machine was used to make Dapanji according to the traditional frying and stewing technique.The contents of free amino acid were measured by amino acid analyzer,Kjeldahl method was used to measure the content of total nitrogen and non-protein nitrogen,the degradation of myofibrillar protein and the transform of microstructure in Dapanji during the stir-fried and stewed processing were investigated by the SDS-PAGE and Scanning electron microscope.Results:The results indicated that the content of free amino acids,essential amino acids and flavored amino acids in the finished Dapanji were 48.63%,53.78%and 55.78%,respectively,which were higher than that of the raw chicken,and the contents were as high as 30.38,12.61 and 13.74 g/100 g,respectively.The contents of total nitrogen(TN)and non-protein nitrogen(NPN)in the finished Dapanji were significantly reduced(P<0.05)compared with the raw chicken.Compared to the stir-firing processing,the degree of degradation of myofibrillar protein(molecular weight 97 kDa)and protein(molecular weight 15~25 kDa)were increased after the stewing treatment,which was shown in SDS-PAGE.The protein band of molecular weights 47,55 and 60 kDa were found in SDS-PAGE after the chicken were stir-fried and stewed,indicating that the heavy chains of myosin in the chicken were degraded.The results of scanning electron microscope showed that the sarcolemma dissolved and fiber tissue structure was tight in during the stir-fried and stewed processing.Conclusion:Dapanji was made by using the intelligent frying machine,which not only maintained the traditional sensory quality and flavor,but also shorten the processing time and improved the work efficiency.