Chitosan and postharvest decay of fresh fruit: Meta-analysis of disease control and antimicrobial and eliciting activities

Consumers are increasingly aware of the importance of regular consumption of fresh fruit in their diet. Since fresh fruit are highly sensitive to postharvest decay, several investigations focused on the study natural compounds alternative to synthetic fungicides, to extend their shelf life. A long list of studies reported the effectiveness of the natural biopolymer chitosan in control of postharvest diseases of fresh fruit. However, these findings remain controversial, with many mixed claims in the literature. In this work, we used random-effects meta-analysis to investigate the effects of 1% chitosan on (a) postharvest decay incidence; (b) mycelium growth of fungal pathogens Botrytis cinerea, Penicillium spp., Colletotrichum spp. and Alternaria spp.; and (c) phenylalanine ammonia-lyase, chitinase and beta-1,3-glucanase activities. Chitosan significantly reduced postharvest disease incidence (mean difference [MD], -30.22; p < 0.00001) and in vitro mycelium growth (MD, -54.32; p < 0.00001). For host defense responses, there were significantly increased activities of beta-1,3-glucanase (MD, 115.06; p = 0.003) and chitinase (MD, 75.95; p < 0.0002). This systematic review contributes to confirm the multiple mechanisms of mechanisms of action of chitosan, which has unique properties in the natural compound panorama. Chitosan thus represents a model plant protection biopolymer for sustainable control of postharvest decay of fresh fruit.

Automated summary

Studies have shown that 1% chitosan significantly reduces postharvest disease incidence and in vitro mycelium growth of fungal pathogens, while increasing activities of plant defense-related enzymes. This systematic review confirms the multiple mechanisms of action of chitosan, making it a model plant protection biopolymer for sustainable control of postharvest decay of fresh fruit.