Antimicrobial and cushioning carboxymethyl cellulose hydrogel for strawberry quality preservation and shelf-life extension.

During storage and transportation, fruits and vegetables are prone to quality deterioration, reduced shelf life, and consequent economic losses, primarily due to the combined effects of microbial proliferation and mechanical damage. In this study, a multifunctional hydrogel cushion was developed using methacrylated carboxymethyl cellulose and κ-carrageenan as the polymeric backbone. The mechanical strength of the hydrogel network was reinforced through the synergistic coordination of quaternized cellulose nanofibers and zirconium ions. To impart antimicrobial functionality, a natural antibacterial system composed of ε-polylysine and tannic acid was incorporated, enabling the hydrogel cushion to simultaneously provide mechanical protection and microbial inhibition. The resulting CKQPZ hydrogel exhibited an energy dissipation coefficient ranging from 29.28% to 55.37% under compressive strains of 50%-70%, demonstrating significantly enhanced cushioning performance compared with commercial polyethylene foam. Moreover, the CKQPZ-TA₃₀ hydrogel achieved antibacterial efficiencies of 97.66% against Escherichia coli and 99.22% against Listeria monocytogenes, both of which are common postharvest pathogenic bacteria associated with strawberries. Furthermore, under storage conditions of 25 °C and 70% relative humidity, the hydrogel effectively preserved the visual appearance and nutritional attributes of strawberries. Overall, this study provides a promising strategy for the development of sustainable and multifunctional preservation materials for strawberries and other perishable horticultural products during postharvest handling and distribution.