牦牛肉烤制过程中游离氨基酸对风味物质的影响

Effect of Free Amino Acid Changes on Flavor Substances of Yak Meat during Roasting

为研究烤制过程中游离氨基酸变化对牦牛肉风味物质的影响,采用感官描述、气相色谱-离子迁移谱(GC-IMS)、氨基酸自动分析仪检测游离氨基酸,通过气味活性值(OAV)、味道强度值(TAV)来确定关键化合物浓度与游离氨基酸呈味阈值间的关系。结合正交偏最小二乘法判别分析(OPLS-DA)和主成分分析(PCA)等多元统计分析化合物的变化。结果表明:采用GC-IMS共鉴定出95种化合物,包括:醛类17种、醇类14种、酯类18种、酮类17种、酸类2种、杂环类13种、烯烃类14种。其中,酮类含量21.01%~28.57%,是影响最大的化合物,可使牦牛肉呈现奶香味、果味。其次是杂环类物质含量,在15.26%~22.55%,可使牦牛肉呈现坚果、蘑菇、烤肉风味。游离氨基酸共检测出17种,其中Glu、Ala、Trp含量最高,使牦牛肉呈现鲜甜滋味。Arg是牦牛肉关键呈味氨基酸。PCA分析表明:样品yak-C、D风味最佳,样品yak-B、E、F相似。研究结果为牦牛肉风味特征辨别及氨基酸呈味机理提供参考依据。

In order to study the effect of free amino acids on flavor compounds of yak meat during baking and their correlation,sensory description and gas chromatography-ion mobility spectrometry(GC-IMS) were used,automatic amino acid analyzer detects free amino acids,odor activity value(OAV) and taste activity value(TAV) were used to determine the relationship between the concentration of key compounds and the taste threshold value of free amino acids,and the changes and effects of key compounds were analyzed by orthogonal partial least squares discrimination analysis(OPLSDA) and principal component analysis(PCA),respectively,using multiple least squares statistics.The results showed that 95 compounds were identified by GC-IMS,including 17 aldehydes,14 alcohols,18 esters,17 ketones,2 acids,13 heterocyclic compounds and 14 alkenes.The most influential compounds were ketones(21.01%-28.57%),which could make yak meat present milk flavor and fruit flavor,followed by heterocyclic compounds(15.26%-22.55%),which could make yak meat present nut,mushroom and roast flavor.A total of 17 kinds of free amino acids were detected,among which Glu,Ala and Trp were the most prominent,which made yak meat taste sweet.Arg was the key flavor amino acid of yak meat.PCA analysis showed that yak-C and D had the best flavor and yak-B,E and F were similar.The results provide a reference for distinguishing the flavor characteristics of yak meat and the flavor mechanism of amino acids.