Effect of long-term storage on glucosinolate and S-methyl-l-cysteine sulfoxide hydrolysis in cabbage (Brassica oleracea var. capitata)

Abstract

Cabbages are good sources for glucosinolates and S-methyl-l-cysteine sulfoxide (SMCSO), precursors to bioactive volatile hydrolysis products such as isothiocyanates, sulfides and thiosulfinates. Often, white and red cabbages are stored at 0 °C for many months before being sold. Here, we investigated the effect of storage for up to eight months on glucosinolates, SMCSO and the formation of isothiocyanates and derived amines, (epithio)nitriles and volatile organosulfur compounds (VOSCs) in white and red cabbages. Further, the effect of storage on protein expression was evaluated. Overall, glucosinolates and well as SMCSO contents were stable during storage. While in white cabbage glucosinolate hydrolysis was not much affected, in red cabbage storage increased formation of isothiocyanates and methylthioalkylamines, which was linked with reduced epithiospecifier protein 1 abundance. Long-term storage reduced formation of VOSCs from SMCSO which correlated with decline in predicted cystine lyase. Therefore, storage maintains these phytonutrients and can increase formation of health-promoting isothiocyanates.

Keywords: Amine; Glucosinolate; Isothiocyanate; Isothiocyanate hydrolase; Storage; Thiosulfinate; Volatile organosulfur compounds.