基于GC-MS与多变量分析方法的不同储藏期大米挥发特征气味的分析

Analysis for Volatile Gases of Rice with Different Storage Periods Based on GC-MS and Multivariate Analysis Method

通过顶空固相微萃取结合气相色谱质谱联用技术(GC-MS)对两个品种的大米(苏软香型米和武育粳米)在陈化过程中的挥发性气体进行分析。本研究采用主成分分析(PCA)载荷因子分析不同储藏时间大米特征挥发气体,其中对不同储藏时间的苏软香型米的贡献率较大的挥发性物质有壬醛,2-甲基丁醛,正己醛,2-戊基呋喃,而区分不同储藏时间的武育粳米的标志性物质有1-辛烯-3醇,正己醛,18-冠醚-6,丙酮,15-冠醚-5。通过相关性分析表明,各挥发气体之间相关性普遍较小。本研究采用主成分分析结合线性判别法(LDA)对两个品种不同储藏期大米进行分析,研究结果表明,当主成分数为6时,不同储藏期大米均被100%识别。此外,本研究采用聚类分析对两个品种不同储藏时间大米进行分类,研究结果表明,10个批次的大米可以被分为苏软香型新米,苏软香型陈米和武育粳米三大类,这较好的验证主成分分析的结果。

The volatile gases of the two varieties of rice （＂ Wu Yu＂ rice and ＂Suruanxiang＂ rice） in the process of aging were analyzed by headspace SPME combined with gas chromatography mass spectrometry （ GC - MS ）. In this study, the principal component analysis （PCA） load factor was used to analyze the volatile gases of rice with different storage times. The volatile substances with greater contribution rate to the different storage times of ＂Suruanxiang＂ rice were nonaldehyde, 2 -methyl- butanal, hexanal, 2 -pentyl furan, and the symbolic substances to distinguish different storage times of ＂Wu Yu＂ rice were 1 -octene -3 alcohol, hexanal, 18 -crown ether- 6, acetone, 15 - crown ether - 5. The correlation analysis showed that the correlation between the volatile gases was generally small. In this study, the principal component analysis and linear discriminant method （LDA） were used to analyze the two varieties of rice in different storage periods. The results showed that when the number of principal components was 6, the two varieties of rice in different storage periods were both identified by 100%. In addition, this paper adopted the cluster analysis to classify the two varieties of rice in different storage times, and the results showed that the 10 batches of rice could be divided into three categories, namely, the new ＂Suruanxiang＂ rice, the aged ＂Suruanxiang＂ rice and ＂Wu Yu＂ rice, which effectively verified the results of the principal component analysis.