Widely targeted metabolomics reveal the glucosinolate profile and odor-active compounds in flowering Chinese cabbage powder

Widely targeted metabolomics were performed to explore the differences in glucosinolate and odor-active compound levels between flowering Chinese cabbage powder (FCCP) under vacuum-drying and oven-drying conditions. Twenty-three aliphatic, five indole, and three aromatic glucosinolates were identified in two pretreated FCCP. Higher aliphatic glucosinolate levels were retained in vacuum-dried cabbage powder compared to oven-dried samples, and they were negatively correlated with treated temperatures. A total of 36 major odor contributing compounds were detected, including 5 sulfur compounds, 10 aldehydes, 9 heterocyclic compounds, 7 nitriles, 3 acids, and 2 others. 5-Hexenenitrile and (methyldisulfanyl)methan, provide typical pungent, sulfous, and vegetable notes in FCCP. Four major GSLs, namely 2(R)-hydroxy-3-butenyl glucosinolate, (2S)-2-hydroxy-4-pentenyl glucosinolate, 5-(methylthio)pentyl glucosinolate and 2-phenylethyl glucosinolate were the key precursors to form odor-active compounds. Higher temperatures in thermal effects promotes the formation of sulfur-containing and nitrile compounds compared to the vacuum-dried ones. This work can provide a guide for flavor and nutrition retention in FCCP process.