牦牛乳软质干酪成熟期挥发性风味成分分析

Analysis of Volatile Compounds in Yak s Milk Soft Cheese during Ripening

采用固相微萃取-气相色谱-质谱联用(SPME-GC-MS)对不同成熟时期(30、60、90d)牦牛乳软质干酪挥发性风味物质进行分离鉴定,共检测出45种化合物,并用峰面积归一化法确定各种化合物的相对百分含量。通过对固相微萃取纤维头和萃取温度的筛选优化实验条件,采用75μmCAR/PDMS(碳分子筛-聚二甲基硅氧烷)萃取纤维头,50℃条件下吸附不同成熟时期(30、60、90d)干酪的挥发性风味物质效果较好。检测出的挥发性风味物质主要是酸类、醇类、酮类,其次为酯类和醛类化合物,酸类物质构成了牦牛乳软质干酪的主体特征风味。乙酸、丁酸、己酸成为干酪中的优势风味物质。

The flavor components in different ripening periods（30,60 d and 90 d） in yak＇s milk soft cheese were extracted by solid phase micro-extraction（SPME） and identified by gas chromatography-mass spectrometry（GC-MS） analysis.A total of 45 compounds were detected and relative contents of these compounds were determined by peak area normalization method.The conditions of SPME were optimized to be 75μm CAR/PDMS and temperature of 50℃.The major volatile flavor compounds in yak＇s milk soft cheese were acids,alcohols and ketones.Esters and aldehydes were also detected as the volatile flavor components.Acidic compounds were the major flavor components of yak＇s milk soft cheese,among which,acetic acid,butyric acid,caproic acid and 2-heptanone were the most predominant compounds.