Effect of Edible Coatings, Storage Time and Maturity Stage on Overall Quality of Tomato Fruits

Problem statement: Tomato (Lycopersicon esculentum Mill.) is one of the most widely consumed fresh vegetables in the world; however, its highly perishable nature limits its postharvest life. Major losses in tomato quality and quantity occur between harvest and consumption. Therefore, the application of new technologies to extend the postharvest life of this commodity is needed. The use of edible coatings appears to be a good alternative. Approach: We evaluated the effect of carnauba and mineral oil coatings on the postharvest quality of tomato fruits (cv. “Grandela”). Stafresh 2505™ (carnauba) and Stafresh 151™ (mineral oil) coatings were applied on fresh tomatoes at two maturity stages (breaker and pink). The quality of tomatoes was evaluated periodically at 0, 5, 10, 15, 21 and 28 days of storage at 10°C, plus 2 days at 20°C. For respiration rate analysis, tomatoes were kept at 20°C for 16 days. Results: At the beginning of the study, CO₂ production was reduced by 38 and 46% when applying the mineral oil coating on breaker and pink tomatoes, respectively. In addition, early during the study, the mineral oil coating showed suppression of ethylene biosynthesis at both maturity stages. Both coatings reduced 30% PG activity of tomato tissue. At the end of storage, mineral oil coatings delayed color changes and reduced weight losses for up 70 and 46% at the breaker and pink stages, respectively. Conclusion/Recommendations: Respiration rate, color, weight loss and enzyme activity were positively affected by mineral oil coating at both maturity stages. No effects on firmness, titratable acidity and pH were found by the coating application. We concluded that mineral oil coating could be a good alternative to preserve the quality and extend the postharvest life of tomato fruit.