不同乳酸菌接种发酵对泡白菜理化特征及风味的影响

Effect of different lactic acid bacteria inoculation fermentation on the physicochemical characteristics and flavor of Chinese cabbage pickles

为评估泡白菜中乳酸菌的发酵特性,以植物乳杆菌(Lactobacillus plantarum)PC295、肠膜明串珠菌(Leuconostoc mesenteroides)PC137、柠檬明串珠菌(Leuconostoc citreum)PC222、食窦魏斯氏菌(Weissella cibaria)PC311、清酒乳杆菌(Lactobacillus sakei)PC229、短乳杆菌(Lactobacillus brevis)PC330为发酵菌株,分析不同乳酸菌接种发酵对泡白菜pH、总酸、还原糖、微生物数量、有机酸、游离氨基酸、挥发性风味成分的影响。经6种乳酸菌接种发酵后,泡白菜的pH、还原糖、柠檬酸、苹果酸、游离氨基酸总量以及大肠杆菌数量均下降;不同种乳酸菌表现出不同的发酵性能,植物乳杆菌PC295和短乳杆菌PC330发酵速度快,还原糖消耗量和产酸量高,抑制大肠杆菌效果好;异型发酵菌株产较多的乙酸和乙醇。采用顶空固相微萃取-气相色谱-质谱联用技术共检出挥发性风味物质56种,所有泡菜组均以醇类化合物为主,主要包括乙醇、1-辛烯-3-醇、顺-2-戊烯-1-醇等;清酒乳杆菌PC229和短乳杆菌PC330发酵的泡白菜中,反,反-2,4-庚二烯醛、己醛等醛类化合物和乙酸的相对含量高于其他组;主成分分析结果显示,肠膜明串珠菌PC137和柠檬明串珠菌PC222发酵的泡白菜成熟后其挥发性风味相似。不同种乳酸菌在泡白菜发酵速度、风味类型和底物消耗上存在差异。研究结果为进一步开发白菜类泡菜发酵剂奠定了基础。

Lactobacillus plantarum PC295,Leuconostoc mesenteroides PC137,Leuconostoc citreum PC222,Weissella cibaria PC311,Lactobacillus sakei PC229,and Lactobacillus brevis PC330 were chosen as the research strains to evaluate the fermentation characteristics of lactic acid bacteria(LAB)in Chinese cabbage pickles.On the pH,total acid,reducing sugar,microbial amount,organic acid,free amino acid,and volatile taste components of pickles,the effects of inoculation and fermentation with various LAB strains were examined.The outcomes demonstrated that following inoculation with six different LAB strains,the pH,reducing sugar,citric acid,malic acid,total free amino acid,and the amount of Escherichia coli in Chinese cabbage pickles all decreased.The fermentation capabilities of LAB strains were diverse.Both L.plantarum PC295 and L.brevis PC330 fermented quickly,consumed a lot of reducing sugar and produced a lot of acid,and effectively inhibited E.coli.Heterologous fermentation strain produced more acetic acid and ethanol.A total of 56 volatile taste components were found using headspace-solid phase microextraction-gas chromatography-mass spectrometry.All pickle groups exhibited a predominance of alcohol molecules,including ethanol,1-octen-3-ol,and(Z)-2-penten-1-ol.In comparison to other groups,Chinese cabbage pickles fermented by L.sakei PC229 and L.brevis PC330 had greater relative levels of aldehydes like(E,E)-2,4-heptadienal,hexanal,and acetic acid.The results of principal component analysis showed that the volatile flavor of pickles fermented by L.mesenteroides PC137 and L.citreum PC222 were similar after maturation.The pace of Chinese cabbage pickles fermentation,flavor profile,and substrate consumption varied among LAB species.The results provide the framework for further research and development of fermenters for pickles made from Chinese cabbage.