Glucosinolate metabolism, myrosinase activity, and isothiocyanate formation in cruciferous vegetables: Health implications and processing effects

Abstract

Cruciferous vegetables contain glucosinolates that release bioactive isothiocyanates upon tissue damage through myrosinase-catalyzed hydrolysis. This research examined glucosinolate content, myrosinase activity, and isothiocyanate formation in broccoli, cabbage, and kale under different processing conditions. Experiments conducted at São Paulo Institute of Technology from November 2023 to March 2025 quantified glucosinolates by HPLC and isothiocyanates by cyclocondensation assay. Results showed broccoli contained the highest total glucosinolates at 42.8 μmol/g dry weight, with glucoraphanin comprising 58% of the profile. Myrosinase activity varied 3.4-fold among species, with kale showing highest activity at 2.8 units/g fresh weight. Boiling for 10 minutes reduced glucosinolate content by 72% and eliminated myrosinase activity, while steaming preserved 84% of glucosinolates and 45% of enzyme activity. These findings inform processing recommendations to maximize health-promoting compound retention.