Application of antioxidant peptide-based coating on fresh-cut apple

Fresh-cut apples are susceptible to enzymatic browning and spoilage. The objective of this study was to evaluate the effect of different coatings on fresh-cut apples and develop a predictive model for their shelf life. The apples were treated with antioxidant peptide from Candida utilis (CUH), carboxymethyl chitosan (CMCS), and composite coatings, and their physicochemical properties were subsequently evaluated. Key factors identified through correlation analysis of shelf life were used as input parameters for a partial least squares regression (PLSR) model to predict the shelf life of fresh-cut apples treated with different coatings. The results indicate that CUH, CMCS, and CUH-CMCS coatings effectively delay the deterioration of fresh-cut apples. Notably, the CUH-CMCS composite coating demonstrated superior performance, showing only a slight 3.50% increase in the browning index (BI) during storage. Minimal changes were observed in weight loss and firmness, while overall total acidity (TA) and pH exhibited slight decreases. Moreover, the levels of ascorbic acid (Vc), polyphenol oxidase (PPO), and peroxidase (POD) were significantly lower compared to the control group, and the total bacterial count increased by no more than 0.7 log CFU g⁻¹. The PLSR model accurately predicted the shelf life of fresh-cut apples treated with different coatings, with $R_c^2$ and $R_p^2$ values both exceeding 0.90. The research results indicate that the coating and model developed in this study offer a novel approach for preserving and managing fresh-cut apples.