Effect of melatonin treatment on visual quality and health-promoting properties of broccoli florets under room temperature

Effect of melatonin treatment on visual quality and contents of health-promoting compounds of broccoli florets under room temperature was investigated in the present study. Broccoli florets were treated with 1 mu M melatonin and then stored at room temperature. Results showed that melatonin treatment could delay the post-harvest senescence of broccoli, and performed well in maintaining higher levels of antioxidants, such as carotenoids, vitamin C and total phenols, as well as higher antioxidant capacity than the control. Besides, 1 mu M melatonin treatment sustained higher content of glucosinolates, and also resulted in increased percentage of the most potent anticarcinogenic profile, glucoraphanin. Further analysis revealed that 1 mu M melatonin strongly induced the expression of glucosinolate biosynthesis-related genes BoMYB28, BoMYB34, BoCYP79F1, and BoCYP79B2, as well as BoTGG1, a gene involved in glucosinolate hydrolysis. In conclusion, post-harvest treatment with 1 mu M melatonin is potential in maintaining visual quality and health-promoting properties of broccoli florets.