Evaluation of the volatile composition and isothiocyanates of violet cauliflower

The volatile compounds and the content of isothiocyanates of five landraces of violet cauliflower (cv 157, cv 25, cv 75, cv 98, and cv 141) and one selective line set up by DOFATA (cv 98 S1/3) were studied. The volatile compounds, obtained from endogenous enzymatic hydrolysis of glucosinolates, were extracted and concentrated from each sample using a microwave-KS112 apolar resin coupled technique. The volatile extracts were quali-quantitatively analysed by GC/MS. All the samples had almost the same characteristic volatile compounds of the Brassicaceae family (isothiocyanates, nitriles, sulfures, and thionitriles) and carbonilic compounds (aldehids and chetons), but the quantitative aroma profiles were different. The high concentrations of isothiocyanates (3-5 mg/100 g s.s.) and carbonilic compounds (15-21 mg/100 g s.s.) were found in cv 98 and cv 141. The concentrations of sulfures were ranged from 6 to 9 mg/100 g s.s. in all the samples. The concentrations of nitriles and thionitriles were below 1 mg/100 g s.s. in all the samples, except for cv 98. The cv 98 could be considered more aromatic in respect of others for the higher content of total volatile substances; cv 141 contained the higher concentrations of specific isothiocyanates which could control human cancer.