自筛菌株PM-1脂肪酶的提取及对脱脂乳风味改进的研究

Purification of Lipase and its Application in Improvement of Skimmed Milk Flavor

摘要:

本文将筛选到的、对乳脂肪有高度专一性的脂肪酶高产菌株PM-1发酵，上清液经硫酸铵沉淀、透析脱盐、蒸发浓缩后获得的粗酶提取液是原上清液酶活的4.5倍。将粗酶液发酵稀奶油产物用于90%脱脂乳中，感官评定效果良好，并通过测定增香90%脱脂乳中的游离脂肪酸和挥发性风味物质可知，增香后的90%脱脂乳中中链及部分长链脂肪酸增加，对奶香有突出贡献的特征性风味物质显著增长。从而肯定了该菌株所产脂肪酶的应用潜质。

Abstract:

Lipase-producing strain PM-1 was fermented. The lipase activity of the extracted solution from supernatant through ammonium sulphate precipitation, desalting and evaporation concentration was found to be 4.5 times of the untreated supernatant. The hydrolyzed cream by this lipase could improve milk flavor. Analysis of composition of free fat acid and volatile milk fat aroma showed that moderate-length chain and some long chain free fat acid in skimmed milk increased and the characteristic flavor substance increased significantly.