Sprout vegetables have emerged as functional instant foods, with elevated concentrations of bioactive compounds compared with their mature counterparts. Chinese kale (Brassica oleracea var. alboglabra) is a cruciferous Brassica vegetable particularly rich in phenolic compounds, glucosinolates, and other nutrients, making it a suitable candidate for sprout production. This study aimed to explore the impact of melatonin (MT), calcium chloride (CaCl2), and their combination on the quality and functional metabolism of Chinese kale. The results showed that MT treatment alone led to significantly higher ferric-reducing antioxidant power and concentrations of chlorophylls, carotenoids, soluble sugar, soluble protein, flavonoid, total phenolic compounds, and glucosinolates than those under CaCl2 treatment alone. CaCl2 treatment alone increased ascorbic acid content by 30.5%, but had limited effects on protein accumulation and secondary metabolites. However, the combined treatment did not exert a synergistic effect on ascorbic acid content, which decreased by 19.8% compared with that under the control treatment, significantly (p < 0.05). Overall, MT treatment was effective in boosting nutrient levels, thereby elevating the functional quality of Chinese kale sprouts.
Liang et al. (Sun,) studied this question.