川西高原牧区传统发酵牦牛酸奶挥发性风味成分的分析

采用顶空固相微萃取-气相色谱/质谱联用技术,以普通酸奶为对照,检测并分析了川西高原牧区传统发酵牦牛酸奶的挥发性风味成分。研究结果显示,川西高原牧区传统发酵牦牛酸奶的主体挥发性风味物质为乙醇（13%³4%）、3-甲基-1-丁醇（4%¹5%）、2-甲基-1-丁醇（1%⁸%）和乙酸乙酯（1%¹0%）,与普通酸奶存在明显差异,丰富的醇类物质是牦牛酸奶呈现醇香的直接原因。传统牦牛酸奶中乙醛、双乙酰和乙偶姻的相对百分含量低于普通酸奶,且短链及中链脂肪酸(C₂^C₁₀)的总百分含量低于普通酸奶。总体而言,川西高原牧区传统发酵牦牛酸奶的风味物质组成复杂,分布较为分散,不同风味化合物之间相互平衡的结果使得乳香与醇香适度搭配、香味丰满。 

Analysis of volatile components of traditional fermented yak yogurt in the western Sichuan plateau

Volatile components of traditional fermented yak yogurt in the western Sichuan plateau were detected by headspace solid phase microextraction gas chromatography- mass spectroscopy( HS- SPME / GC- MS),and common yogurt products available from supermarkets were used as controls. The results showed that the main flavor components of traditional fermented yak yogurt in the western Sichuan plateau consisted of ethanol( 13% ~34%),3- methyl-1- butanol( 4% ~15%),2- methyl-1- butanol( 1% ~8%) and ethyl acetate( 1% ~10%),which were obviously different from common yogurt products. Abundant alcohols provided yak yogurt with alcohol aroma.Compared to common yogurt products,the acetaldehyde,2,3- butanedione and 3- hydroxy-2- butaone accounted for smaller proportions in the traditional fermented yak yogurt,and the total percentage of short and medium chain fatty acids( C₂~ C₁₀₎ in yak yogurt was lower. Generally,thevolatile components of the traditional fermented yak yogurt were complex and dispersive,and the flavor of yak yogurt was mixed with milk aroma and alcohol aroma.