不同来源产香酵母分离鉴定及玉米发酵特征风味物质分析

Isolation and Identification of Aroma-producing Yeasts from Different Sources and Analysis of Characteristic Flavor Compounds in Corn Fermentation

摘要:

为筛选适合发酵玉米的产香酵母并开发发酵香精，该研究以5种市售产品为材料，通过菌株分离培养、分子生物学鉴定，结合感官评价与顶空固相微萃取-气相色谱质谱联用技术，系统分析其发酵玉米的风味特征。结果表明，分离的5株酵母均鉴定为异常威克汉姆酵母，但其发酵玉米风味存在显著差异。感官结果显示菌株ANQSX酯香突出，菌株PJ和HZKY甜香显著。GC-MS共鉴定出136种挥发性风味物质，以醇类（25种）、酯类（34种）、醛类（14种）、酸类（16种）为主要的挥发性有机物，其中BLD发酵样品中的挥发性风味物质种类最丰富，含67种。采用PLS-DA分析得到59种潜在的特征风味成分（VIP>1），结合ROAV值筛选得到47种关键风味物质（ROAV>1），通过二者筛选主要特征差异成分是(E,E)-2,4-壬二烯醛、香叶醇、苯乙醇、庚酸等物质，赋予发酵耙玉米清香、醇香、果香。该研究揭示了不同异常威克汉姆酵母在玉米发酵中风味指纹图谱及关键风味化合物，为玉米发酵制品风味定向调控及天然香精开发提供指导与理论支撑。

Abstract:

To screen aroma-producing yeasts suitable for corn fermentation and to develop fermented flavorings, five yeast products were used to corn fermentation. Yeast strains were isolated, cultured, and identified using molecular biology techniques. The flavor characteristics of the fermented corn were systematically analyzed by combining sensory evaluation and headspace solid-phase microextraction coupled with gas chromatography-mass spectrometry (HS-SPME-GC-MS). The results showed that all five isolated yeast strains were identified as Wickerhamomyces anomalus. However, significant differences were observed in the flavor profiles of the fermented corn produced by these strains. Sensory evaluation results indicated that strain ANQSX exhibited a distinct ester aroma, while strains PJ and HZKY displayed a significant sweet aroma. A total of 136 volatile flavor compounds were identified by GC-MS. The main volatile organic compounds belonged to alcohols (25 types), esters (34 types), aldehydes (14 types), and acids (16 types). The fermented sample with strain BLD contained the richest variety of volatile flavor compounds (67 types). Fifty-nine potential characteristic flavor components (VIP>1) were identified through Partial Least Squares Discriminant Analysis (PLS-DA). Based on Relative Odor Activity Value (ROAV) analysis, 47 key flavor compounds (ROAV>1) were screened. The main characteristic differential components identified by combining these two methods included (E,E)-2,4-nonadienal, geraniol, phenethyl alcohol, and heptanoic acid. These compounds were found to impart fresh, mellow, and fruity aromas to the fermented glutinous corn. This study revealed the flavor fingerprints and key flavor compounds of different Wickerhamomyces anomalus strains in corn fermentation. It is considered to provide guidance and theoretical support for the directional regulation of flavor in corn fermented products and the development of natural flavorings.