Active packaging incorporating chitosan, casein phosphopeptide, and plasmonic modification to maintain quality and regulate the respiration rate of fresh-cut Pyrus serotina Rehder during storage

In this study, chitosan (CS), casein phosphopeptide (CPP), and plasm modification were used to develop an active packaging that can extend the shelf-life of fresh-cut pear (FCP) (Pyrus serotina Rehder) at 4 °C. Results show that CS, CPP, and plasmonic modification increase water vapour permeability (WVP), improved the antibacterial (8%) and antioxidant properties (58–69%) of low-density polyethylene (LDPE) without adverse effects on mechanical strength. The application of CS/CPP active packaging resulted in significant improvements in various quality parameters of the packaged product. Browning was reduced by 48.80%, while weight loss decreased by 14.56%. The active packaging also exhibited potent inhibitory effects on microbial growth and respiration, with reductions of 47.74%. Additionally, the packaging demonstrated the ability to reduce the activity of crucial enzymes such as phospholipase D (PLD) by 35.71%, lipoxygenase (LOX) by 40.74%, polyphenol oxidase (PPO) by 35.71%, and malondialdehyde (MDA) by 34.79%. These combined effects extended the shelf-life of the FCP from 6 to 12 days. A comprehensive analysis of film properties, including moisture migration and respiration characteristics, indicated that the CS/CPP active packaging primarily contributed to mass loss reduction by inhibiting respiration rather than transpiration. This result proves that combining cold plasma, antioxidants, and antibacterial agents with modified LDPE can create a preservation package with composite functions.