Abstract: In order to elucidate the decomposition of glucosinolates in Brassica juncea var. latipa during thermal processing by different methods, microwave radiation, water blanching and steam blanching were separately used to process the plant that is popular in Yangtze river delta as a traditional vegetable, and the untreated and treated samples of the vegetable were analyzed for their kind and amount of glucosinolates by high performance liquid chromatography (HPLC). The results showed that Brassica juncea var. latipa contained two groups of β-thioglucoside-N-hydroxysulfates, namely the fatty group and indole group, and among them, progoitrin, glucobrassicin and 4-methoxyglucobrassicin were the most abundant compounds. The decomposition of glucosinolates in Brassica juncea var. latipa obeyed the first-order kinetics model regardless of which of the three processing methods was used. Glucotropaeolin displayed the worst thermal stability during the three processes. The decreasing order of the decomposition of glucosinolates in Brassica juncea var. latipa was found to be: steam blanching, water blanching and microwave radiation. Microwave radiation, however, could best drive the decomposition of glucosinolates from the fatty group making the largest contribution to the flavor of cruciferous vegetables.

Key words: glucosinolates, microwave, blanching, steaming, first-order degradation kinetics