Effect of postharvest UV-B irradiation on nutraceutical quality and physical properties of tomato fruits

Nutraceutical (ascorbic acid and carotenoids) and physical (colour and firmness) parameters were evaluated in two tomato genotypes (Money maker and high pigment-1) subjected to post harvest UV-B irradiation at different ripening stages (mature green and turning).UV-B treatment increased the concentration of ascorbic acid and carotenoids in Money maker flesh and peel, while high pigment-1 fruits underwent only minor changes, suggesting that hp-1 mutation decreased the fruit ability to respond to UV-B radiation. Colour parameters appeared to be more influenced by harvesting stages than UV-B with the exception of redness (a∗), which in Money maker was found to increase in both flesh and peel of irradiated fruits at turning stage, although not significantly, while control was more red than treated at mature green stage. Firmness was negatively influenced by UV-B, as tomatoes were found to soften after the treatment, although this aspect needs further studies to be clarified.

► Tomatoes were harvested at two ripening stages and let to ripe with or without UV-B.
► UV-B treatment increased carotenoid and ascorbic acid content in Money maker fruits.
► Irradiated fruits of high pigment-1 showed very few changes in nutraceutical content.
► Colour parameters were more influenced by harvesting stage than UV-B treatment.
► Fruit firmness was negatively affected by UV-B irradiation in both genotypes.