A study on coating of Hydroxypropyl methylcellulose incorporated with a nano-emulsion of Piper betel leaf essential oil to enhance shelf-life and improve postharvest quality of Tomato (Solanum lycopersicum L.)

Edible coating films derived from essential oils effectively preserve farm produce, especially fruits and vegetables, and the technology is widely prevalent in improving their shelf life. The present study aimed to reduce the post-harvest loss and extend the shelf life of tomatoes using edible coatings based on Hydroxypropyl methylcellulose (HPMC) containing Piper betel leaf essential oil nano-emulsion as an antibacterial and bioactive compound. It also aimed for optimal extraction of essential oils (EO) from Piper betel leaves which contain various medicinal, antimicrobial, and antioxidant compounds such as chavibetol, eugenol, and other compounds. The essential oils were extracted, and nano-emulsion was prepared by a low-energy emulsification method and incorporated into edible HPMC composite to determine whether the edible coatings of the nano-emulsion of Piper betel leaf could delay the changes that lead to deterioration of the fruit. Results showed that the coatings delayed 5 % changes in color, 8% weight loss, titratable acidity, ascorbic acid content, soluble solids concentration, lycopene, and decay percentage, compared to uncoated control fruits. It was inferred that tomatoes that were coated with 15% nano-emulsion containing dipping solution showed a significant increase in the shelf life of tomatoes up to 8 days. Therefore, it is suggested to use HPMC containing the Piper betel oil nano-emulsion as an edible coating, extending the shelf-life of tomato fruits post-harvest.