Magnetic field-assisted blanching enhances sulforaphane synthesis in broccoli florets, revealed by...

Sulforaphane (SF) is generated from glucoraphanin hydrolysis catalyzed by endogenous myrosinase in Brassicaceae vegetables such as broccoli, with blanching critical to maximize SF formation. However, the effect of magnetic field (MF) treatment on glucoraphanin hydrolysis remains unclear. This study investigated MF-assisted blanching of broccoli florets under 0-10 mT, monitoring myrosinase activity and quantifying SF, sulforaphane nitrile (SFN), and precursor glucosinolates using UPLC-ESI-QTRAP-MS/MS. MF-assisted blanching significantly enhanced myrosinase activity and SF formation, with the greatest effect at 1.0 mT, where myrosinase activity increased 3.11-fold and SF content reached 61.14 ± 1.21 μmol/100 g fresh weight, a 1.89-fold increase relative to the control (blanching only). SFN increased but remained at trace levels, reaching 3.10 ± 0.10 μmol/100 g fresh weight at 1.0 mT versus 0.24 ± 0.09 μmol/100 g in the control. Enhanced hydrolysis was supported by residual glucosinolate levels. These findings suggest a promising strategy to improve SF content in broccoli.