Calcium sulfate treatment enhances bioactive compounds and antioxidant capacity in broccoli sprouts during growth and storage

The effect of preharvest CaSO4 treatment on antioxidant enzyme activities, bioactive compounds and antioxidant capacity in broccoli sprouts during growth and storage was investigated in this study. Application of CaSO4 increased the biomass and reduced electrolyte leakage of broccoli sprouts. Higher antioxidant enzyme activities and antioxidant capacity in sprouts were obtained in CaSO4-treated sprouts during growth and storage. Total phenolic content in CaSO4-treated sprouts was lower than that in control ones during growth; but was higher than in control sprouts during storage. Additionally, the decrease of ascorbic acid was suppressed by CaSO4 treatment during storage. CaSO4 treatment also dramatically enhanced glucosinolate content, especially glucoraphanin, in broccoli sprouts during growth and prevented its loss during storage. This was further supported by the up-regulation of glucoraphanin biosynthesis-related genes. During storage, CaSO4-treated sprouts exhibited higher myrosinase activity and lower ESP activity, which resulted from higher expression of MYR and ESM1. Moreover, CaSO4 treatment led to higher sulforaphane formation in sprouts than control during growth and storage.