CaCl2–HCl electrolyzed water promotes glucosinolate metabolism in broccoli sprouts via calcium signalling

Abstract

Background

Electrolyzed water, a green chemistry invention, is a novel disinfectant that has been widely used in the food field. Previous studies have found that slightly acidic electrolyzed water not only has a bactericidal effect but also promotes the accumulation of active substances in many types of sprouts. We developed a new type of electrolyzed water, CaCl₂–HCl electrolyzed water (CHEW), which can effectively enhance the formation of glucosinolates and isothiocyanates in broccoli sprouts. The molecular mechanism by which CaCl₂–HCl electrolyzed water promotes glucosinolate metabolism in broccoli sprouts during growth was investigated in this study.

Results

On the 4th day, the total glucosinolate content in broccoli sprouts reached 195.50 μmol/g DW under CHEW treatment. On the 8th day, compared to treatment with tap water, the contents of three isothiocyanates (sulforaphane, erucin, and 4-isothiocyanato-1-butene) in broccoli sprouts under CHEW treatment were significantly increased by 45.93, 34.04 and 185.15%, respectively. The results of calcium distribution and qRT‒PCR assessments indicated that CHEW treatment activated calcium signalling in broccoli sprouts and promoted the relative expression of glucosinolate biosynthesis-related genes through calcium sensors [calmodulin (CaM), calmodulin-like protein (CML), and calcium-dependent protein kinase (CDPK)] and the calcium-binding nuclear protein IQD1.

Conclusion

Our research provides new insights into the molecular mechanism of glucosinolate metabolism and a theoretical basis for cultivating high-quality broccoli sprouts.