On-demand removable hydrogel film derived from gallic acid-phycocyanin and polyvinyl alcohol for fruit preservation

Postharvest spoilage of fruits accounts for significant losses ranging between 20 %-30 %, leading to considerable resource wastage and economic downturns. The development of an effective fresh-keeping packaging material is of paramount importance. This study introduces an innovative on-demand removable active fruit fresh-keeping film (GPP), created by embedding a GP (gallic acid-phycocyanin) fiber mesh hydrogel with functional properties into a polyvinyl alcohol (PVA) matrix. The resultant GPP hydrogel-based film demonstrates outstanding UV and water vapor barrier capabilities, mechanical stability, resistance to external mechanical stress, universal surface adhesion, antibacterial efficacy, and on-demand removal attributes, while being devoid of potential toxicity hazards. Utilizing grapes and blueberries as representative fruits, it is shown that the GPP hydrogel film significantly preserves the fruits' hardness, pH, total soluble solids content (TSS), and minimizes the rate of weight loss, thereby prolonging the shelf life to 13 days for grapes and 20 days for blueberries at ambient temperature. These results underscore the potential of this hydrogel-based film as an invaluable material for fruit preservation within the food industry.