烘烤前后6种胚芽米风味成分的变化

目的 分析烘烤前后6种胚芽米的风味物质,为胚芽米的风味评价和相关加工产品的开发推广提供依据。方法 利用顶空固相微萃取结合气相色谱-质谱法(solid phase micro extraction-gas chromatography-mass spectrometry, SPME-GC/MS)对6种胚芽米烘烤前后的风味物质进行检测。通过质谱谱库比对结合标准化合物保留指数进行风味物质的定性鉴定,采用峰面积归一化方法进行定量。结果 检测出42种风味物质,包括烃类、醇醚类、醛酮类、杂环类等。烘烤之后的胚芽米中烃类、1-己醇、1-壬醇含量普遍降低,而己醛、壬醛、糠醛、5-甲基糠醛、糠醇、2-戊基呋喃、3-乙基-2,5-二甲基吡嗪、2,4-癸二烯醛、2-庚烯醛含量普遍升高。最后,利用主成分分析(principalcomponentanalysis,PCA)能够有效将不同品种胚芽米及烘烤前后的胚芽米进行区分。结论 利用SPME-GC/MS结合PCA分析手段能够检测、区分烘烤前后不同品种胚芽米中风味物质的变化,为胚芽米的品种选育及加工提供一定的参考价值。

Changes of flavor components of 6 kinds of germ-remaining rice before and after roasting

Objective To analyze the flavor compounds of 6 kinds of germ-remaining rice before and after roasting, and provide basis for flavor evaluation of germ-remaining rice and development and popularization of related processed products. Methods The flavor compounds of 6 kinds of germ-remaining rice before and after roasting were detected by headspace solid phase micro extraction-gas chromatography-mass spectrometry (SPME-GC/MS). The compounds were identified by comparing the retention index and mass spectra with that in library and quantified by area normalization. Results The 42 kinds of flavor compounds, including hydrocarbons, alcohols, aldehydes, ketones, heterocycles and so on were identified. The roasting procedure reduced the content of hydrocarbons, 1-hexanol, 1-nonyl alcohol while increased the levels of hexanal, nonanal, furfural, 5-methyl furfural, furfuralcohol, 2-pentyl furan, 3-ethyl-2,5-dimethyl pyrazine, 2,4-decadienal and 2-heptenal. Besides, the principal component analysis (PCA) technique was applied effectively distinguished the germ-remaining rice before and after roasting. Conclusion The SPME-GC/MS method combined with PCA can be used to detect the change trend of flavor compounds in germ-remaining rice before and after roasting, which can provide some reference value for variety breeding and processing of germ rice.