发酵和后熟对牦牛奶营养及风味物质的影响

为研究发酵和后熟对牦牛奶营养成分及风味物质的影响,分析了牦牛奶、发酵后牦牛奶和后熟后牦牛奶中的营养成分和挥发性物质种类和相对含量的变化,并进行了营养和品质评价.结果表明,发酵显著降低了牦牛奶中的乳糖含量(P<0.05),降幅为39.43％;发酵还显著促进了牦牛奶中总氨基酸、必需氨基酸、非必需氨基酸和鲜味氨基酸含量的增加...

Effect of Fermentation and Post-fermentation on Nutritional Composition and Volatile Substances of Yak Milk

In order to investigate the nutritional composition and volatile substances of yak milk after fermentation and postfermentation,the changes of nutrients and volatile substances of yak milk,fermented yak milk and post-fermented yak milk were measured,and the nutrition and quality of yak milk were evaluated.The results showed that the lactose content of yak milk after fermentation was significantly decreased(P<0.05),and the decreased rate was 39.43%.The contents of total,essential,non-essential and delicious amino acids of yak milk after fermentation were significantly increased(P<0.05),and the increased rate were 64.26%,57.52%,69.33% and 56.67%,respectively.The content of fatty acid of yak milk after fermentation has no significantly difference(P>0.05),but the types and relative contents of alcohols,aldehydes and esters in yak milk after ferentation were greatly decreased.There were no significant differences in lactose,amino acid and fatty acid contents between post-ferentation and ferentation of yak milk(P>0.05),but the types and relative contents of alcohols,phenols,esters and ketones in post-ferentated yak milk greatly increased compared to fermented yak milk.In summary,fermentation improved the nutritional value of yak milk in some extent,and post-fermentation promoted the accumulation of volatile substances of yak milk.Fermentation and post-fermentation had positive effect on the improvement of nutrition and quality of yak milk.