发酵牦牛肉成熟过程中挥发性香气成分的变化

为探讨发酵牦牛肉挥发性香气成分在成熟过程中的变化规律,本文采用固相微萃取法（SPME）对各取样点样品中挥发性物质进行提取,利用气相-嗅闻-质谱联用法对其中的挥发性成分进行定性和定量分析。总计有84种挥发性成分被鉴定,其中,经嗅闻鉴定的香气活性化合物有48种,包括烃类（12）、醇类（8）、酮类（7）、醛类（3）、酸类（3）、含硫化合物（2）、酯类（4）、含氮类化合物（7）和酚类（2）。在成熟过程中,烃类和酮类含量整体呈现波动变化。醛类和酯类含量在成熟前期增加,而后又降低。酸类和吡嗪类形成于成熟过程,含量逐渐增加。烃类是成品发酵牦牛肉风味组成中含量最高的,其次是醇类、酮类及吡嗪类化合物。香辛料的添加、氨基酸的降解及微生物的代谢对发酵牦牛肉的香气形成具有重要作用。 

Changes in volatile aroma compounds during ripening of fermented yak meat

The objectives of this study were to discuss the changes in volatile aroma compounds of fermented yak meat during ripening. Volatile compounds in fermented yak meat were extracted by solid-phase micro extraction(SPME). Gas chromatography-olfactometry-mass spectrometry(GC-O-MS) was used to identify and quantify these compounds. A total of 84 volatile compounds were identified. Among these compounds,48aroma-active compounds were identified by GC-O,including hydrocarbons(11),alcohols(8),ketones(7),aldehydes(3),carboxylic acids(3),sulfocompound(2),esters(4),nitrogenous compounds(7),and phenols(2).During ripening,the content of hydrocarbons and ketones showed fluctuation changes. The content of aldehydes and esters increased during the first ripening stage,and then decreased. Carboxylic acids and pyrazines were formed and increased during ripening. Hydrocarbons were the most abundant volatile compounds in the final product,followed by alcohols,ketones,and nitrogen compounds. Spices,amino acids degradation,and microbial metabolism played a key role in the flavour formation of fermented yak meat.