Effect of Beeswax Coating on the Quality of Eggplant Fruit During Cold Storage and Optimization of Coating Conditions

Eggplants are highly nutritious and feature prominently in food recipes in the tropics. However, losses in weight, firmness, and nutrients affect the quality of the fruit after harvest. This work investigated the use of beeswax as a potential coating to improve the quality of eggplant fruit. Eggplant fruit were coated with a 3% beeswax solution alone or in combination with a citrate solution and stored at 10°C for 17 days. The coating significantly minimized weight loss, preserved firmness, and delayed colour changes. No changes in total phenols and antioxidant capacity were observed upon coating; however, ascorbate levels decreased. Using a response surface methodology approach the optimum conditions for the application of beeswax coating to improve the quality of eggplant fruit was investigated. The validated optimum coating conditions were 4.6% (w/v) coating concentration, 1% (w/v) citrate concentration, and 3 min coating duration. The validation experiment gave a high correlation coefficient (R2) of 0.93 between the predicted and measured physicochemical properties of the fruit. The optimized conditions can be useful in the preparation of a beeswax-based coating for improving the quality of eggplant fruit during cold storage.