Active Packaging of Chitosan-casein Phosphopeptide Modified Plasma–treated LDPE for CO2 Regulation to Delay Texture Softening and Maintain Quality of Fresh-cut Slice Persimmon During Storage

Abstract

This study addresses the challenge of short shelf life of fresh-cut fruits, using fresh-cut slice persimmon (FSP) as a model. The aim of study was to develop active packaging by combining chitosan-casein phosphopeptides (Ch-CPP) coating onto low-density polyethylene (LDPE) film to delay softening by inhibiting cell wall degrading–related enzymes and extend the shelf life of the fruit. Key quality parameters, including gas composition, respiration rate, texture softening, and cell wall polysaccharide were evaluated during 15 days of storage at 4 °C. Compared to the control, Ch-CPP0.5 reduced the browning index by 31.53% and weight loss by 41%. In addition, Ch-CPP0.5 active packaging effectively reduced respiration rates by 18.27% and maintained the internal packaging’s CO₂ levels by around 5%. This regulation suppressed cell wall–degrading enzyme activities, such as polygalacturonase (PG), pectin methylesterase (PME), and cellulase (Cx). Consequently, Ch-CPP0.5 delayed firmness loss by increasing water-soluble pectin (WSP) while reducing ionic-soluble pectin (ISP), covalent-soluble pectin (CSP), and cellulose degradation. In addition, our active packaging significantly extended FSP shelf life from 9 to 15 days while maintaining quality attributes. These results demonstrate that Ch-CPP0.5 effectively inhibits the breakdown of cell wall polysaccharides, delays the softening process, and preserves FSP texture. This study underscores the effectiveness of Ch-CPP active packaging as a strategy for preserving fresh-cut fruit texture.

Graphical Abstract