机械脱水一次腌制榨菜在腌制过程中香气成分的变化

为了研究机械脱水一次腌制(低盐)榨菜在腌制过程中香气成分的变化,采用顶空固相微萃取(headspacesolid phase micro-extraction,HS-SPME)结合气相色谱-质谱联用(gas chromatograph-mass spectrometry,GC-MS)法对机械脱水一次低盐腌制榨菜不同腌制时间的香气成分进行测定。结果表明,榨菜腌制过程中的主要香气成分为异硫氰酸酯类和醇醛类,其变化与腌制过程中芥子苷分解和微生物发酵直接相关。腌制6 d后,榨菜中异硫氰酸酯类相对含量达到22.33%,随着腌制的进行,其相对含量呈下降趋势。醇醛类香气成分以硫二甘醇为主,其相对含量呈先上升后降低趋势,21 d时相对含量达到24.85%。酯类和杂环类物质变化较为复杂;酸类香气成分的种类和相对含量总体呈下降趋势;烷烃类和其它类香气成分分别以2,5-二甲基辛烷和顺式-4-甲基-2-戊烯为主。

The Changes of Aroma Components in Zhacai during One-Time Pickling after Mechanical Dehydration

In order to study the changes of aroma components in the process of pickling Zhacai(low salt)in mechanical dehydration,the headspace solid phase microextraction combined with gas chromatography-mass spectrometry(GC/MS)was used to determine the aroma components of low salt Zhacai in different periods. The results showed that the main aroma components of Zhacai pickling were isothiocyanates and aldehydes,which were directly related to the glucosinolates decomposition and microbial fermentation in the process of pickling. The relative content of isothiocyanates in Zhacai pickling reached 22.33% after 6 d of pickling,and then decreased with the pickling process. Thiodiglycol was the main aroma component of alcohols and aldehydes. The relative content of alcohols and aldehydes increased and then decreased and the relative content reached 24.85% at 21 d. The changes of esters and heterocyclic compounds were more complex;the types and relative contents of acid aroma components showed a general downward trend;alkanes and other aroma components were mainly 2,5-dimethyl octane and cis-4-methyl-2-pentene,respectively.