甘肃牧区传统风干牦牛肉加工过程中挥发性风味物质变化分析

Analysis of the changes of volatile flavor compounds during processing of traditional air-dried beef in pastoral area in Gansu province

以甘肃甘南牦牛肉为研究对象,探讨其在自然冷冻风干过程中挥发性风味物质的组成及变化规律。采用顶空固相微萃取(headspace solid-phase microextraction,HS-SPME)与气相色谱-质谱(gas chromatography-mass spectrometry,GC-MS)对风干牦牛肉加工过程中第0、2、4、6、8、10、15、20、25、30、40、50、60天的风味物质进行了定性和定量分析。结果显示,甘肃牧区传统风干牦牛肉在加工过程中总共检出41种挥发性风味物质,其中酯类(12种)、酸类(6种)、醛类(3种)、酮类(9种)、醇类(3种)、醚类(1种)、烃类(1种)、含硫化合物(4种)、杂环化合物(2种)。在整个风干过程中,酯类、酮类、醇类总相对含量总体呈现降低趋势,酸类、烃类和醚类未呈现明显的变化规律,醛类在风干过程中呈现先增加后降低,含硫化合物总相对含量整体呈显著增加趋势(P<0.05)。对风干牦牛肉加工过程中41种挥发性风味物质进行主成分分析,结果表明,第一主成分主要来源于美拉德反应,主要有1,2-乙二硫醇、苯乙醛、2,3-辛二酮等;第二主成分主要来源于脂肪氧化产物,主要有α-酮戊二酸、正己醇、3-甲基戊酸等; 0～15 d是风味形成的关键阶段。

The yak meat,which is from Gannan area in Gansu province was taken as the research object to study the composition and changing rules of its volatile flavor compounds during natural freeze-drying process. The flavor compounds of air-dried yak meat during process on day 0,2,4,6,8,10,15,20,25,30,40,50 and 60 were quantitatively and qualitatively analysed by using headspace solid-phase microextraction (HS-SPME) and gas chromatography-mass spectrometry (GC-MS). The results showed that a total of 41 kinds of volatile flavour compounds were detected during traditional air-drying process of beef in the pastoral areas of Gansu,including esters (12),acids (6),aldehydes (3),ketones (9),alcohols (3),ether (1),hydrocarbon (1),sulfur-containing compound (4),and heterocyclic compound (2). During the whole air-drying process,the total relative contents of esters,ketones,and alcohols overall showed a decreasing trend. Acids,hydrocarbons,and ethers did not show obvious changes. Aldehydes increased at first and then decreased during the air-drying process. The total relative contents of sulfur compounds showed a significant increasing trend ( P <0.05). The results of principal component analysis of these 41 kinds of volatile flavor compounds during the air-drying process of yak meat showed that the first main component mainly came from the Maillard reaction,which mainly included 1,2-ethanedithiol,phenylacetaldehyde,2,3-hendanedione etc. The second main component mainly came from fat oxidation products,which mainly included α-ketoglutarate,n-hexanol,3-methylvalerate etc. 0 th -15 th days was found to be the key stages for flavor formation.