Enhancement of postharvest quality and antioxidative ability in broccoli sprouts by preharvest application of hydrogen sulfide

Broccoli sprouts are valued for their rich nutritional profile but are prone to postharvest spoilage and rapid quality deterioration. Preharvest application of hydrogen sulfide (H₂S) has emerged as a promising strategy to enhance postharvest shelf life. In this study, broccoli sprouts were treated with varying concentrations (0, 0.2, 0.4, 0.6, 0.8, 1.0, 1.2, 1.4, 1.6, 1.8 and 2.0 mM) of NaHS solutions (H 2 S donor) 24 h preharvest, with 1.0 mM identified as the optimal concentration. After harvest, sprouts were stored at 25 ℃ for 7 days, and samples were analyzed on days 0, 1, 3, 5, and 7. This study assessed changes in appearance, weight loss, electrolyte leakage, total phenols, flavonoids, phenolic acids, antioxidant enzyme activity, reactive oxygen species, and related gene expression. Preharvest 1.0 mM NaHS treatment significantly delayed yellowing, reduced weight loss and decreased electrolyte leakage compared to the control. It increased total phenols by up to 34.5 % at 5 d postharvest. Specific phenolic acids (chlorogenic acid, ferulic acid, caffeic acid, sinapic acid) and flavonoids (quercetin, cynarin) were significantly elevated. Antioxidant defense was strengthened, with peroxidase activity 12.7 % higher at 1 d, superoxide dismutase up to 51.3 % higher at 7 d, and catalase peaking earlier and at higher levels than in the control, along with activation of the AsA-GSH cycle. In addition, H 2 S treatment upregulated the expression of key genes, including PAL , CM , C4H , C3H , SOD , POD , CAT , and GPX . In summary, preharvest application of 1.0 mM H₂S effectively delayed senescence, enhanced phenolic accumulation, and strengthened antioxidant capacity in broccoli sprouts, offering a practical approach for improving their postharvest quality. • H₂S effectively enhances the quality and mitigate nutrient loss of broccoli sprouts. • H₂S activates the shikimic acid and phenylpropanoid metabolic pathways. • H₂S regulates both enzymatic and non-enzymatic antioxidant systems.