Durian fruit is rich in volatile sulfur compounds (VSCs), especially thiols and disulfides, which contribute to its onion-like odor. After fermentation, these VSCs were reduced to trace or undetectable levels in durian wine. The possible reduction mechanism of these VSCs (especially diethyl disulfide and ethanethiol) was investigated in a modified buffer in the presence of sulfite at different pH. An interconversion between diethyl disulfide and ethanethiol was found to be dependent on the pH:

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... he higher the pH, the higher production of ethanethiol. It is suggested that, during durian wine fermentation, disulfides endogenous to durian pulp might be firstly converted into their corresponding thiols in the presence of reductant sulfite formed by yeast. The produced thiols as well as the thiols endogenous to the durian pulp were then removed by the mannoproteins of yeast lees. Durian is a well-known tropical fruit in Southeast Asia; this is largely a result of its particular onion-like odor which is contributed to by volatile sulfur compounds (VSCs), especially thiols (ethanethiol and propanethiol) and disulfides (diethyl disulfide and ethyl isopropyl disulfide) that are endogenous in durian pulp [1, 2] . The major and common VSCs present in durian fruit are shown in Scheme 1. The VSCs extracted from durian pulp can react with glutathione with the release of hydrogen sulfide (H2S), which is reported to be beneficial to anticancer and cardiovascular diseases [3]. Scheme 1. Structures of the main volatile sulfur compounds in durian fruit. Scheme 1. Structures of the main volatile sulfur compounds in durian fruit.