Bioactive Edible Coatings for Fresh-Cut Apples: A Study on Chitosan-Based Coatings Infused with Essential Oils.

Abstract

This study developed chitosan-based active edible coating formulations with antioxidant and antimicrobial properties exhibited by oregano and cinnamon leaf essential oils (EOs) to extend the shelf life of fresh-cut 'Braeburn' apples. The primary coating consisted of chitosan (1.5% w/v), ascorbic acid (2% w/v), and citric acid (2% w/v). Oregano (0.06 and 0.15% v/v) and cinnamon leaf (0.06 and 0.1% v/v) EOs were added to the primary coating. The coated apple slices were stored for 9 days at 4 ± 1 °C. Changes in weight loss, water activity, titratable acidity, total soluble solids content, polyphenol oxidase (PPO) activity, firmness, colour, visual appearance, surface morphology, and microbial activity were measured on days 2 and 9. The results revealed that the control samples deteriorated rapidly during storage. However, higher concentrations of EOs reduced moisture loss, water activity, and acid conversion but slightly impacted visual appearance. The coatings effectively inhibited the PPO activity through storage. The formulation with 0.1% cinnamon leaf EO may be considered a viable candidate for application as a coating material, followed by the formulation containing 0.06% oregano EO, maintaining the optimum quality parameters of fresh-cut apples. Chitosan-based coatings with added EOs can be a promising alternative for maintaining fresh-cut apple quality during storage.