Abstract:Broccoli contained glucosinolates，which could be hydrolyzed by endogenous myrosinase to obtain isothiocyanates （ITCs）.However，myrosinase was easily inactivated during the cooking process，thus the concentration of ITCs decreased after cooking.In this paper，the ITCs contents of the extracts of raw broccoli（RB），direct stir-fried broccoli （DS），hydrolyzed and stir-fried broccoli （HS）were compared and the proliferation inhibitory effects and quinone oxidoreductase （NQO1）induced activities of broccoli extracts of RB，DS and HS groups on mouse melanoma B16 cells were studied.The results showed that the highest content of total ITCs was （36.22±12.01）mg/100 mg in the RB group and the contents of ITCs in the DS and HS groups were（10.64±2.41）mg/100 mg and（30.90±10.88）mg/100 mg，respectively，there were no significant differences in the contents of extracts between the RB and HS groups （P＞0.05）and the content of extracts in DS group was the lowest.There were no significant differences in the proliferation inhibitory effect of broccoli extracts on B16 cells（P＞0.05）.The activities of NQO1 in cells of the control group，RB，DS and HS groups were（4.22±1.60），（19.53±3.59），（12.58±4.32）and（22.57±3.56）（nmoL MTT/min/mg protein），respectively，and the extracts from the RB and HS groups significantly increased the activity of NQO1，which were significant differences with the DS group （P＜0.05）.Therefore，compared with raw broccoli，the ITCs contents and activities of hydrolyzed and stir-fried broccoli had no significant difference，this cooking method could effectively maintained the functional components and nutritive values of broccoli.