Mechanisms underlying the anti-spoilage effects of plant extracts on postharvest mung bean sprouts

Abstract

Plant extracts are commonly incorporated into the processing of agricultural products to exert preservative effects. However, the molecular mechanisms underlying their decay-inhibiting effects remain poorly understood. Identifying plant extracts with potent anti-spoilage activity is especially crucial for mung bean sprouts ( Vigna radiata ), which are highly susceptible to rapid decay after harvest. In this study, we comparatively evaluated the efficacy of five extracts (mango seed MS, loquat leaf LL, rosemary R, horsetail H, mate tea MT) on preserving sprouts quality. LL extract achieved optimal quality retention, whereas R accelerated spoilage; MS, H, and MT produced intermediate effects. Integrated transcriptomic and metabolomic analyses revealed that LL extract maintained quality by: (i) reinforcing membrane integrity through the activation of antioxidant system and the suppression of lipid degradation; (ii) enhancing biosynthesis of phenylpropanoids and alkaloids, particularly methyl 4-hydroxycinnamate, naringenin and securinine, which inhibited enzymatic browning and microbial proliferation; and (iii) promoting fructose accumulation while downregulating genes associated with cell wall degradation, thereby delaying tissue softening and water loss. In contrast, R extract depleted these protective metabolites, exacerbated oxidative damage and browning. Notably, securinine, an endogenous metabolite sustained by LL, suppressed the growth of spoilage microorganisms and delayed sprout deterioration. Our work provides insights into plant extract–mediated postharvest quality maintenance and highlights securinine as a promising candidate for developing effective strategies to suppress decay in highly perishable vegetables.