[关键词]
[摘要]
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。
[Key word]
[Abstract]
The dynamic changes in the composition and content of volatile components during the solid-state fermentation to produce traditional Chinese vinegar Daqu were analyzed by headspace-solid phase microextraction–gas chromatography–tandem mass spectrometry (HS-SPME-GC-MS). A total of 56 volatile compounds, including 22 esters, 11 alcohols, 9 aldehydes, 3 ketones, 1 acid, 3 alkanes, 1 heterocyclic compound, 1 pyrazine, 3 benzene containing compounds, 1 amine and 1 other compound, were isolated and their quantities determined at various stages of fermentation. The quantities of most of these volatile components declined after the initial increase. Esters and alcohols reached their maximum values on days 3 and 7, respectively, and stabilized during the late stage of the fermentation; aldehydes and ketones reached their peak values on day 13, and gradually decreased afterwards. However, acids continued to increase until they attained the maximum value on day 30. Principal component analysis (PCA) was also performed to compare the profiles of the volatile components at various stages of the solid-state fermentation with those obtained by HS-SPME-GC-MS. The results from both methods were consistent. Both sets of results indicated that significant changes in the relative content of the volatile components occurred on days 3, 7, and 13 of the fermentation to produce Daqu, and the content tended to stabilize during the later stages of fermentation.
[中图分类号]
[基金项目]
国家自然科学基金资助项目(31271924)