Changes in volatile compounds of pickled mustard tuber (Brassica juncea var. tsatsai) during the pickling process

This study was carried out to determine the changes of volatile compounds composition during pickled mustard tuber production. The samples were collected at different pickling stages from the traditional industry production way in Chongqing, China. Gas chromatography–mass spectrometry were performed after simultaneous distillation and extraction. The results showed that ITC (isothiocyanates) possessed the highest relative percentage area (RPA) 78.87%, followed by sulphide compounds with RPA of 14.48%. Main volatile compounds that determined were allyl ITC, dimethyl trisulphide, (2-isothiocyanatoethyl)-benzene, n-Hexadecanoic acid and linolenic acid ethyl ester, which were responsible for the hot and pungent flavour of pickled mustard tuber. The sulphides, acids, aldehydes, alcohols, phenols, esters, nitriles and heterocyclic compounds increase with pickling time but ITC increase at the first and second pickling stage, then start to decrease in the last pickling stage. It was also demonstrated that more than 60-day pickling time was necessary for the formation of the typical aroma notes.