Effect of 2, 4-epibrassinolide on main health-promoting compounds in broccoli sprouts

•Effect of EBR on the nutrition in broccoli sprouts are investigated.•Impacts of EBR and NaCl on the glucosinolate-myrosinase system are revealed.•EBR has a concentration-dependent effect on the content of glucosinolates.•Treatment with 2 nmol/L EBR and 40 mmol/L NaCl enhances glucosinolates content.•20 nmol/L EBR improves the accumulation of ascorbic acid in broccoli sprouts.

The combined treatment with 2, 4-epibrassinolide (EBR) (2, 20, and 200 nmol/L) and NaCl (0, 40, and 160 mmol/L) on the germination rate, fresh weight, contents of ascorbic acid and glucosinolates, activities of myrosinase and antioxidant ability of broccoli sprouts was investigated. The influence of EBR on the content of glucosinolates in broccoli sprouts varied with the concentrations of EBR and NaCl. The content of total glucosinolates and glucoraphanin in broccoli sprouts treated with 2 nmol/L EBR plus 40 mmol/L NaCl was increased by 86% and 85%, respectively, and the activity of myrosinase was significantly improved by 20 nmol/L EBR treatment with or without NaCl. In addition, the content of ascorbic acid was significantly increased after treatment with 20 nmol/L EBR, and the combined treatment with 20 nmol/L EBR plus 40 mmol/L NaCl significantly enhanced the accumulation of ascorbic acid when compared with the 40 mmol/L NaCl treatment alone. These results indicated that the combined treatment with 2 nmol/L EBR plus 40 mmol/L NaCl as well as EBR treatment solely at 20 nmol/L could be useful ways for selective increase of glucosinolates or ascorbic acid, the main health-promoting compounds in broccoli sprouts.