Edible Coating Containing Cashew Gum and Lemongrass Essential Oil Extends the Shelf Life of Tomatoes at 13°C

Abstract

In many developing countries, the high cost of post-harvest technologies is a limiting factor. This study evaluated the effectiveness of inexpensive edible coatings, prepared from local gum, in preserving the quality of tomatoes stored at 13°C for 25 days. Different formulations were applied, some with and some without the addition of essential oil. The results showed that the coatings slowed the deterioration of physicochemical parameters. While untreated tomatoes lost 37 N of firmness and deteriorated by 25% after 25 days, the coated samples retained a firmness greater than 25 N and showed no visible deterioration. The color variation remained between 5 and 18 for the coated samples, compared to more than 25 for the control samples, indicating a delay in ripening and enzymatic browning. The ripeness index of untreated tomatoes increased from 7 to 14 in 15 days, reaching 14 between 22 and 25 days. At the same time, the pH of coated tomatoes remained below 6. Coatings containing 15% and 20% gum proved to be the most effective in slowing ripening. The addition of essential oil enhanced the antimicrobial and antioxidant properties of the coatings. Storage at 13°C amplified the protective effect, delaying ripening and stabilizing the pH between 5.2 and 5.5. In conclusion, edible coatings made from local, inexpensive raw materials are an effective and accessible method of extending the shelf life of tomatoes and preserving their physical and chemical qualities.