Phytochemical profiling of volatile and bioactive compounds in yellow mustard (Sinapis alba) and oriental mustard (Brassica juncea) seed flour and bran

The objective was to study the phytochemical profile of yellow (Sinapis alba) and oriental mustard (Brassica juncea) flour and bran fractions. The HS-SPME-GC/MS technique was used to determine the volatile profile. Up to 53 volatiles, including isothiocyanates, alkanes, alcohols, ketones and esters were identified in the mustard powders. In addition, the free and bound bioactive fraction was studied and the determination was performed by UHPLC-MS/MS. A total of 26 compounds (phenolic acids, flavonoids and glucosinolates) were identified in the mustard samples. Sinapis alba, including the bran fraction, was richer in p-hydroxybenzoic, ferulic and p-coumaric acids compared to Brassica juncea. In addition, the volatile profile in yellow mustard seeds, as analysed by HS-SPME-GC/MS, has been described for the first time in this work. The study of the principal components showed that according to the bioactive compounds profile it is possible to differentiate between the two mustard species analysed. Moreover, the bran fraction, as a by-product of the seed processing, is a matrix rich in bioactive compounds and could be applied for the recovery of polyphenols for agro-industrial or pharmaceutical application.