The flavor of Chinese kale sprouts is affected by genotypic variation of glucosinolates and their breakdown products

Metabolic profiling of glucosinolates and their breakdown products in sprouts of 22 Chinese kale (Brassica oleracea var. alboglabra, BOA) varieties were investigated by using high-performance liquid chromatography (HPLC) and gas chromatography-mass spectrometry (GC-MS). Relationships between glucosinolate metabolites and flavor of Chinese kale sprouts were also analyzed. Results showed that compositions and contents of both glucosinolates and their breakdown products varied greatly among different varieties of Chinese kale sprouts. Gluconapin and 4,5-Epithio-pentanenitrile were the dominant glucosinolate and glucosinolate breakdown product in Chinese kale sprouts, respectively. Gluconapin and glucobrassicin were significantly related to bitterness (r = 0.577, 0.648, respectively; p < 0.05). BOA 1 and BOA 13, BOA 3 and BOA 10 are good candidates for future breeding programs since the former two varieties have light bitterness and pungency, and the latter two varieties contain high levels of glucosinolate breakdown products such as isothiocyanates and epithionitriles in sprouts.

Automated summary

Varieties of Chinese kale sprouts exhibit significant variations in compositions and contents of glucosinolates and their breakdown products. Gluconapin and 4,5-Epithio-pentanenitrile are identified as the dominant compounds in Chinese kale sprouts. Additionally, glucobrassicin and gluconapin are found to be significantly correlated with bitterness. BOA 1, BOA 13, BOA 3, and BOA 10 are promising candidates for future breeding programs based on their unique characteristics.