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采用顶空固相微萃取和气相色谱-质谱联用(HS-SPME-GC-MS)技术,研究传统食醋大曲固态发酵过程中挥发性成分组成和含量变化。GC-MS共分离鉴定出挥发性化合物56种,包括酯类22种,醇类11种,醛类9种,酮类3种,酸类1种,烷类3种,杂环类1种,吡嗪类1种,含苯类3种,胺类1种,其他类1种。大部分挥发性成分相对含量呈现先增后减的趋势。其中酯类、醇类化合物含量分别在第3、7 d达到最高值,并在后期趋于稳定。醛类、酮类化合物含量在第13 d达到最高值,随后逐渐降低。而酸类物质呈积累趋势,并在第30 d达到峰值。采用主成分分析(PCA)比较大曲固态发酵各阶段挥发性成分差异,所得结果与气质联用方法相一致,均表明大曲发酵过程中挥发性成分相对含量在第3、7、13 d变化较大,而后期趋于稳定。
Headspace solid-phase microextraction and gas chromatography-mass spectrometry (HS-SPME-GC-MS) were used to study the composition and content of volatile components of traditional vinegar during the solid state fermentation. A total of 56 volatile compounds were identified by GC-MS, including 22 kinds of esters, 11 kinds of alcohols, 9 kinds of aldehydes, 3 kinds of ketones, 1 kinds of acids, 3 kinds of alkanes and 1 kinds of heterocyclic ones. 1 species of pyrazine, 3 species of benzene, 1 species of amines and 1 species of other species. The relative content of most volatile components showed the trend of first increasing and then decreasing. Among them, the content of esters and alcohols reached the highest value on the 3rd and 7th day, respectively, and tended to be stable in the later period. The content of aldehydes and ketones reached the highest value on the 13th day, then decreased gradually. The acid substances showed a tendency of accumulation and reached the peak on the 30th day. The principal component analysis (PCA) was used to compare the volatile components in the stages of solid state fermentation of Daqu. The results were in good agreement with the methods of GC-MS. The results showed that the relative contents of volatile components in Daqu during fermentation varied greatly on the 3rd, , While the latter tends to be stable.