3种猪肉汤体系中蛋白质降解产物的比较研究

Comparison of Protein Degradation Products in Pork Broth Cooked by Three Different Methods

对3种不同烹制方法(水煮、炖煮和高压蒸煮)制得的猪肉和汤汁进行感官评定、总蛋白SDS-PAGE凝胶电泳以及总氮(TN)、水溶性氮(WSN)、非蛋白氮(NPN)和游离氨基酸(FAA)含量的比较研究。感官评定结果表明3种工艺分别为水煮30min,炖煮2h和高压蒸煮15min时,烹制所得肉和汤汁口感与风味最佳。总蛋白SDS-PAGE凝胶电泳图谱显示炖煮肉中大分子蛋白降解最为显著,炖煮肉汤中水溶性蛋白含量最高。水煮、炖煮和高压蒸煮使肉汤体系水溶性氮总量分别比鲜肉增加12%、24%和5%,非蛋白氮总量分别增加42%、59%和33%,游离氨基酸总量分别增加61%、78%和51%。炖煮猪肉的蛋白质降解程度比水煮和高压蒸煮高,且大部分蛋白质降解产物转移到汤汁中,赋予肉汤最优的营养和风味。

Sensory evaluation and SDS-PAGE gel electrophoresis were carried out on the pork as well as its broth obtained by three different cooking methods （boiling, stewing and high-pressure steaming）. The total nitrogen （TN）, water soluble nitrogen （WSN）, non protein nitrogen （NPN） and free amino acid （FAA） were also detected. The sensory evaluation suggested that the best palate ability and flavor were achieved with the time of 30 min for boiling, 2 hours for stewing and 15 rain for high-pressure steaming method. The SDS-PAGE profile indicated that after stewing procedure, the high-molecular-mass proteins degraded more effectively and the WSN concentration of the broth was the highest. For the methods of boiling, stewing and high-pressure steming, compared with fresh pork, the pork broth system increased by 12%, 24%, 5% for the total WSN, 42%, 59% and 33% for the NPN, and 42%, 59%, 33% for the FAA, respectively. In stewing procedure, the protein degraded much more than that in other methods. Moreover, most protein degradation products effused into the broth, which provided the best nutrition and flavor for the stewed broth.