S-methyl-L-cysteine sulfoxide and glucosinolate levels in Australian-sourced Brassica vegetables before and after domestic cooking

Caroline R. Hill, Edith Cowan University
Armaghan Shafaei, Edith Cowan University
Mary C. Boyce, Edith Cowan University
Liezhou Zhong, Edith Cowan University
Lois Balmer, Edith Cowan University
Joshua R. Lewis, Edith Cowan University
Jonathan M. Hodgson, Edith Cowan University
Lauren C. Blekkenhorst, Edith Cowan University

Hill, C. R., Shafaei, A., Boyce, M. C., Zhong, L., Balmer, L., Lewis, J. R., Hodgson, J. M., & Blekkenhorst, L. C. (2025). S-methyl-L-cysteine sulfoxide and glucosinolate levels in Australian-sourced Brassica vegetables before and after domestic cooking. Journal of Food Composition and Analysis, 138. https://doi.org/10.1016/j.jfca.2024.107015

Abstract

Currently no data exists on S-methyl-L-cysteine sulfoxide (SMCSO) levels in Australian-sourced vegetables and limited data exists for glucosinolates. The effect of various cooking methods on the retention of SMCSO and glucosinolates in Australian-sourced vegetables is also limited. This study measured SMCSO and ten glucosinolates in a selection of Australian-sourced Brassica vegetables, both raw and after steaming. We additionally measured SMCSO and glucosinolate levels in broccoli after microwaving, stir-frying and boiling. SMCSO contributed greater dry weight (0.6–1.9 %) than total glucosinolates combined (0.3–1.2 %) in these raw cruciferous vegetables. SMCSO levels from highest to lowest were: Brussels sprouts > broccoli > red cabbage > kale > cauliflower > white cabbage > Chinese cabbage; and glucosinolate levels were: Brussels sprouts > white cabbage > broccoli > kale > red cabbage > Chinese cabbage > cauliflower. Both SMCSO and the ten main glucosinolates quantified were relatively stable after light steaming across all vegetables measured, and after microwaving broccoli. Boiling and stir-frying broccoli led to significant losses in SMCSO and the two dominant glucosinolates, glucoraphanin and glucobrassicin (all p < 0.05). Mild steaming and/or microwaving were preferable in retaining SMCSO and glucosinolates, whilst boiling and stir-frying were least favorable.