不同乳酸菌发酵萝卜干挥发性成分分析

为了解不同乳酸菌对发酵萝卜干挥发性成分的影响,用顶空固相微萃取法预处理发酵萝卜干样品,结合气相色谱-质谱联用仪,分析肠膜明串珠菌(B1)、玉米乳杆菌(B2)、副干酪乳杆菌(B3)、乳酸乳球菌(B4)、植物乳杆菌(B5)、植物乳杆菌(L4)和自然发酵(对照)萝卜干中挥发性成分。7组发酵萝卜干中共检测出8类77种挥发性成分,其中含有6种相同成分:苯乙醇、辛酸乙酯、癸酸乙酯、壬酸乙酯、庚酸乙酯、己酸异戊酯。不同菌种发酵萝卜干挥发性成分种类及相对含量有较大差异,B1检出挥发性成分6类35种,B2检出6类25种,B3检出5类19种,B4检出7类30种,B5检出7类33种、L4检出6类31种,自然发酵检出7类37种。发酵萝卜干中的挥发性成分主要包括醇类、酸类、酯类、醛酮类和烯烃类等。自然发酵萝卜干挥发性成分种类多,但大多成分相对含量较低;B2和B3发酵萝卜干挥发性成分种类较少且相对含量较低;B1、B4、B5和L4能促进发酵萝卜干特有风味物质的形成,其中B1能促进醇、烯烃的形成,B4能促进醇、酯和烯烃的形成,L4能促进酯、酮醛和烯烃的形成,B5能促进醇、酯、酮醛和烯烃的形成。

Analysis of Volatile Components in Dried Radish Fermented by Different Lactobacillus Species

In order to understand the effect of different Lactobacillus species on the flavor characteristics of fermented dried radish, headspace solid phase microextraction (SPME) combined with gas chromatography-mass spectrometry (GC-MS) was used to analyze the volatile flavor composition of radishes fermented by Leuconostoc mesenteroides (B1), Lactobacillus zeae (B2), Lactobacillus paracasei (B3), Lactococcus lactis (B4), Lactobacillus plantarum (B5) and Lactobacillus plantarum (L4), and naturally fermented control radish (C). A total of 77 volatile compounds belonging to 8 categories were detected in 7 samples, and 6 of these compounds were common to all samples, including phenylethyl alcohol, ethyl octanoate, ethyl caprate, ethyl nonanoate, ethyl heptanoate and isopentyl hexanoate. The types and relative?contents of volatile components in radish fermented by different strains were distinctly different. A total of 35 volatile compounds from 6 categories were found in B1 fermented radish, 25 from 6 categories in B2 fermented radish, 19 from 5 categories in B3 fermented radish, 30 from 7 categories in B4 fermented radish, 33 from 7 categories in B5 fermented radish, 31 from 6 categories in L4 fermented radish, and 37 from 7 categories in naturally fermented radish. The main volatile components in fermented radish were alcohols, acids, esters, aldehydes, ketones and olefins. Although naturally fermented radish contained the highest number of volatile compounds, many of them were detected at a lower level. The lowest number of compounds and lower contents were found in B2 and B3 fermented radishes. B1, B4, B5 and L4 could contribute to the formation of volatile compounds in fermented radish compared to natural fermentation. B1 could promote the formation of alcohols and alkenes, B4 could promote the formation of the alcohols, esters and olefins, L4 could promote the formation of ester, ketone and olefins, and B5 could promote the formation of alcohols, esters, ketones, aldehydes, and olefins.