Mango kernel starch-based edible coating with lemongrass oil: a sustainable solution for extending tomato shelf life

Abstract

The present study aim was to utilize mango kernel seed for the extraction of starch and their application for developing edible coating enriched with lemongrass essential oil. In addition, the effects of developed edible coatings on the postharvest shelf-life of tomatoes during storage at room (23 ± 2 ºC and cold storage (10 ± 2 ºC) conditions up to 18 and 36 days were investigated. The physiological and biochemical postharvest characteristics such as physiological loss in weight, respiration rate, ethylene production, titratable acidity, total soluble solids, ascorbic acid, color, and firmness were investigated during storage. In addition, the antioxidant activity, lycopene content, phenolic, flavonoid content, and total yeast and mold count were also investigated. These findings highlight the potential of mango kernel seed-based edible coatings for maintaining the postharvest characteristics of tomatoes for up to 15 days for a coated sample at room temperature. In contrast, at 10 °C of storage, the shelf life was 15 days for the control sample and 30 days for coated sample. The coating significantly reduced weight loss by 6.31% and 5.41% after 15 and 30 days of storage at room and cold conditions, respectively. On 15 days of room storage, the coated fruits showed lower weight loss (9.21%), respiration rate (23.41 ml CO₂ kg-¹. h-¹), higher retention of lycopene content (11.58 mg/100 g), firmness (4.67 N), ascorbic acid (13.16 mg/100 g), acidity (0.29%), TPC (18.03 mg/100 g) and antioxidant activity (27.41%) with 6.05 of overall acceptability. The cold storage treated fruits showed less weight loss (8.21%), respiration rate (23.93 ml CO₂ kg-¹. h-¹), lycopene content (11.87 mg/100 g), firmness (4.8 N), ascorbic acid 14.02 mg/100 g), acidity (0.28%), TPC (18.11 mg/100 g), antioxidant activity (26.89%), and overall acceptability (6.08) respectively, on 30 days of storage. The coated samples showed a delay in the respiration peak at both storage conditions, signifying the delay in ripening-associated changes as compared with the control sample. Incorporating lemongrass essential oil into the coating effectively inhibits microbial growth and maintains tomatoes’ quality during storage. The coated tomatoes exhibited better retention of color, total soluble solids, and ascorbic acid content, indicating preservation of nutritional quality. Storage temperature played a crucial role in the effectiveness of the coating, with lower temperatures, (10 °C) showing better results in maintaining tomato quality compared to ambient temperature (25 °C). However, the coating proved beneficial at both temperatures, suggesting its potential for use in various storage conditions. These findings highlight the potential of mango kernel starch-based edible coating with lemongrass essential oil as an eco-friendly and cost-effective solution for extending the shelf life of tomatoes.