Effect of pullulan and pullulan-chitosan composite coating on the antioxidant activity, texture, color and shelf-life of a local cultivar of sweet cherry

This study explored the effects of pullulan and pullulan-chitosan composite edible coatings on the post-harvest quality of sweet cherries over 20 days of storage. We evaluated weight loss, total soluble solids (TSS), decay percentage, color value, texture and biochemical content, including ascorbic acid , total phenolic content (TPC), flavonoids , anthocyanins , antioxidant activity and enzyme activity . The results revealed that cherries with 3 % pullulan coating presented the lowest weight loss (25 % vs 26.33 % in the control) and decay percentage (25 % vs 47 % in the control) and maintained superior texture and stability compared with those of the control and other coatings. TSS increased less in the coated cherries than in the control cherries, with 3 % pullulan-treated cherries showing the least increase, indicating slower ripening. Pullulan coatings effectively reduced color changes, with the 3 % coating delaying darkening in cherries more than the other treatments did. Additionally, the pullulan coating preserved higher levels of ascorbic acid, phenolic compounds (TPC) and flavonoids and delayed the decrease in antioxidant activity . Notably, the 3 % pullulan-treated cherries maintained the highest antioxidant activity (88.97 %) and had the greatest TPC (2.79 mg GAE/g FW) at the end of storage. The activity of enzymes, particularly peroxidase (POD), increased less in coated cherries, highlighting the role of coatings in delaying oxidative stress . Overall, the pullulan coatings, especially at a 3 % concentration, were the most effective at extending the shelf-life and maintaining the quality of the sweet cherries. These findings suggest that the use of a pullulan-based coating is a promising approach for preserving fruit quality during storage, thereby extending shelf-life. These coatings can contribute to a reduction in food waste, improved consumer acceptability and improved economic gains by reducing postharvest losses and maintaining quality. To optimize pullulan-based coatings for commercial application, future research can focus on optimizing the formulation, consumer acceptability and scalability. Moreover, field trials to assess the effectiveness of these coatings in preserving the quality of cherry can be performed. By addressing these areas, future research can contribute to the development of sustainable options for preserving the quality and extending the shelf life of sweet cherries and other fruits.