Application of Encapsulated Garlic Extract Coatings on Tomatoes

Abstract

Edible coatings containing natural bioactive compounds have gained considerable attention as a sustainable approach for extending the postharvest shelf life of fresh produce. The present work aimed at developing a starch–gelatin edible coating containing microencapsulated garlic extract encapsulated in bitter gourd seed protein nanoparticles and evaluated its effectiveness in maintaining the quality of tomatoes stored at ambient temperature (25°C) for 20 days. Tomatoes were coated with different concentrations of encapsulated garlic extract (0, 0.5, 1.0 and 2.0%) and subjected to storage to assess their physicochemical quality attributes. Coated tomatoes exhibited lower moisture loss than the uncoated control, demonstrating that the coatings helped retain moisture and delay quality deterioration during storage. The coatings also helped to maintain relatively stable TSS levels and slow changes in pH and titratable acidity during storage. In addition, coated fruits showed better color retention as reflected by lower browning index values and improved appearance. While all treatments showed reduction in ascorbic acid and an increase in lycopene content as part of the natural ripening process, the coated tomatoes generally showed better retention of the nutritional quality throughout storage. Among all the treatments,, the 2% encapsulated garlic extract coating showed the best performance in reducing  weight loss and maintaining the physicochemical quality attributes of tomatoes during the storage period. Overall, the incorporation of encapsulated garlic extract into edible coating matrix enhanced its ability to delay ripening-related changes and maintain tomato quality during storage. These results indicate that bitter gourd seed protein nanoparticle-encapsulated garlic extract has strong potential as a functional ingredient in active edible coatings for postharvest preservation of tomatoes.