不同乳酸菌发酵对酸菜的风味物质形成及品质指标的影响

为研究不同乳酸菌对于酸菜发酵效果的影响，以白菜为原料，采用植物乳杆菌（Lactobacillus plantarum）、干酪乳杆菌（Lactobacillus casei）和肠膜明串珠菌（Leuconostoc mesenteroides）作为发酵剂进行酸菜发酵，并分析不同乳酸菌发酵体系中的理化指标、感官指标和挥发性风味物质。结果表明，在发酵30 d时，肠膜明串珠菌（L. mesenteroides）发酵酸菜中pH值（3.28）和还原糖含量（2.14 g/L）最低，总酸含量（8.69 g/L）最高，但亚硝酸盐含量无显著差异（P＞0.05）。肠膜明串珠菌（L. mesenteroides）发酵酸菜中乳酸（7.59 g/L）和柠檬酸（1.84 g/L）含量最高，且乳酸占总有机酸的65%。3种乳酸菌发酵酸菜中共检出挥发性风味物质65种，主要包括醛类13种、酯类12种、酸类12种、醇类7种、异硫氰酸酯类5种和酮类4种。主成分分析（PCA）结果表明，不同乳酸菌发酵酸菜的挥发性物质种类和含量差异显著。

Effects of different lactic acid bacteria fermentation on the formation of flavor substances and quality indexes of suan-cai

In order to study the effect of different lactic acid bacteria on suan-cai fermentation, the suan-cai was prepared with Chinese cabbage by Lactobacillus plantarum, Lactobacillus casei and Leuconostoc mesenteroides. The physicochemical indexes, sensory indexes and volatile flavor compounds were analyzed in different lactic acid bacteria fermentation systems. The results showed that the suan-cai after fermentation 30 d with L. mesenteroides had the lowest pH (3.28) and reducing sugar content (2.14 g/L), and the highest total acid content (8.69 g/L), but there was no significant difference in nitrite content (P＞0.05). The suan-cai fermented by L. mesenteroides had the highest lactic acid and citric acid content, which were 7.59 g/L and 1.84 g/L, respectively, and the content of lactic acid accounted for about 65% of the total organic acid content. A total of 65 kinds of volatile flavor compounds were detected in the three lactic acid bacteria fermented suan-cai, including 13 kinds of aldehydes, 12 kinds of esters, 12 kinds of acids, 7 kinds of alcohols, 5 kinds of isothiocyanates and 4 kinds of ketones. The principal component analysis (PCA) results showed that the types and contents of volatile flavor compounds in suan- cai fermented by different lactic acid bacteria were significantly different.