Abstract: 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.

Key words: lactic acid bacteria, fermentation, dried radish, gas chromatography-mass spectrometry (GC-MS), volatile components