Postharvest UV-B irradiation maintains sensory qualities and enhances antioxidant capacity in tomato fruit during storage

Mature-green tomato fruit (Lycopersicon esculentum cv. Zhenfen 202) were exposed to different doses of UV-B irradiation (10, 20, 40 and 80 kJ/m2) and stored in the dark at 14 °C, 95% RH for up to 37 d. Of the four doses, 20 or 40 kJ/m2 was most effective in maintaining a high level of firmness and delaying the colour development. Furthermore, 20 or 40 kJ/m2 promoted the accumulation of total phenolics and total flavonoids, and enhanced antioxidant capacity during storage, though UV-B irradiation could reduce the ascorbic acid content. A dose of 10 kJ/m2 had similar effects but to a lesser extent. The highest dose of 80 kJ/m2 resulted in higher lycopene content, but showed negative effects on texture, colour, and other antioxidants. The optimum dose of UV-B for maintaining sensory qualities and enhancing antioxidant capacity was 20 or 40 kJ/m2. These results suggest that UV-B irradiation appears to be a useful non-chemical way of maintaining postharvest quality and enhancing antioxidant capacity in tomato fruit.

Research highlights▶ Postharvest UV-B treatment maintained firmness and delayed ripening in tomato fruit. ▶ Postharvest UV-B treatment increased total phenolics and flavonoids in the fruit. ▶ Postharvest UV-B treatment maintained or increased antioxidant capacity of the fruit. ▶ UV-B treatment appears to be a potential non-chemical way to regulate fruit quality.