Transparent and water-resistant edible coatings for sustainable post-harvest preservation of banana

Abstract

The rapid spoilage of fresh produce due to water loss remains a major challenge in the post-harvest preservation of fruits and vegetables. While current solutions often rely on plastic packaging, these approaches pose environmental concerns and offer limited biodegradability. This study presents a sustainable alternative by developing transparent and water-resistant edible coatings using a spray-coating method based on natural materials, including gelatin (GE), gum arabic (GA), milk protein isolate (MPI), and coconut oil (CO). Spray coatings were prepared using two groups of formulations, including the GE-based group and the GA-based group. Their physicochemical and functional properties, including visual appearance, hydrophobicity, film thickness, surface roughness, and morphology were systematically evaluated. The optimal formulations identified were 4% GE, 2% MPI, and 4% CO (sample 1-424) for the GE-based group, and 5% GA, 4% MPI, and 1% CO (sample 2-541) for the GA-based group. Both coatings exhibited relatively smooth surfaces, high transparency, and strong water resistance. When applied to bananas stored at room temperature for 10 days, these coatings significantly reduced water loss and delayed visible signs of ripening. These findings highlight the potential of the developed spray coatings for post-harvest preservation. Overall, this work introduces a novel edible coating system that combines food preservation efficacy with environmental sustainability, offering promising applications in green packaging and the large-scale post-harvest treatment of fresh produce.