3种优势微生物对宝泉酱挥发性香气的影响

Correlation Analysis of Three Dominant Microorganisms and Volatile Aroma Components of Baoquan Fermented Soybean Paste

为探究大豆酱中主要菌种与香气成分的关系,采用气相色谱-质谱联用,对人工接种优势菌发酵的大豆酱进行挥发性成分的测定,并利用电子鼻技术与成品宝泉酱的香气成分进行主成分分析。结果表明:经主成分分析,在7个样品中确定BM6的香气与发酵34 d成品大豆酱最接近,BM7的香气差异较大;BM6的发酵风味易被人接受,其人工感官评价与电子鼻结果相一致。利用顶空固相微萃取结合气相色谱-质谱技术,在样品中共检出15种酯类、6种醇类、6种醛酮类、3种酸酚类、8种其他类化合物;宝泉酱中的酯类和醇类主要来源于Zygosaccharomycse rouxii BSZ.16910,醛酮类主要来源于Staphylococcus epidermidis BSS.17312,3种菌株之间在挥发性成分的合成上存在微妙的互作关系;经因子分析,菌株S. epidermidis BSS.17312和Z. rouxii BSZ.16910对宝泉酱酯和醇的产生贡献较大。

The present study was intended to investigate the correlation between the three dominant microorganisms and aroma compounds of Baoquan fermented soybean paste. The volatile compounds of seven samples （BM1, BM2, BM3, BM4, BM5, BM6 and BM7） of fermented soybean paste artificially inoculated with pure or mixed cultures of the dominant microorganisms were identified by headspace solid phase microextraction combined with gas chromatography-mass spectrometry （HS-SPME-GC-MS）. Furthermore, we also detected the volatile aroma compounds of these samples by an electronic nose and analyzed the sensor data by principal component analysis （PCA）. The PCA results showed that the aroma of BM6 was most similar to the commercial product fermented for 34 d whereas BM7 was distinct from this product. The results of sensory evaluation and electronic nose analysis consistently indicated that BM6 was more acceptable to consumers. A total of 38 volatile compounds were identified, including 15 esters, 6 alcohols, 6 aldehydes and ketones, 3 acids and phenolics, and 8 other compounds. The esters and alcohols were derived from Zygosaccharomycse rouxii BSZ.16910 and the aldehydes and ketones from Staphylococcus epidermidis BSS.17312. There existed certain interaction between the three microorganisms on the synthesis of volatile compounds in Baoquan fermented soybean paste. Factor analysis demonstrated that S. epidermidis BSS.17312 and Z. rouxii BSZ.16910 made greater contribution to the generation of esters and alcohols.