关键词: 体细胞, 干酪, 蛋白水解, 风味

Abstract: Proteolysis is an important way of flavor generation during cheese ripening. Manual milking manner in small-scale dairy farms still account al large proportion in China, and this may induce the mixing of somatic cells (SCs) into raw milk, which would exert an effect on the final flavor and quality of cheese. However, the effects of somatic cells on volatile flavor compounds in cheese through proteolysis has not yet been elucidated. In our study, three kinds of skim milk containing different level of somatic cells are used for cheese manufacture after analyzed the somatic cells composition, and the protease activity, proteolysis level among cheese during 90 days of ripening, as well as the volatile flavor compounds and texture of cheese after 90 days of ripening are measured. We found that cheese with higher somatic cell count(SCC) had a higher protease activity and proteolysis on αs2-casein, which resulted influence on volatile flavor compounds and texture of cheese at different degrees: group B(higher SCC) had the highest content of 3-hydroxy-2-butanone (34.57%), which is largely contributing to the flavor of cheese; more Octanal, furfural, octyl ketone, hexanal had been detected in group C(highest SCC), which are considered unfavorable in cheese flavor; the group C had the highest hardness because of the highest level of its` proteolysis.

Key words: somatic cells, cheese, proteolysis, flavor