Evaluation of physicochemical characteristics in cherry tomatoes irradiated with 60Co gamma-rays on post-harvest conservation

Abstract

The aim of this study was to evaluate the effect of gamma radiation doses on storage in postharvest conservation of cherry tomatoes in relation to physicochemical characteristics. The samples of cherry tomatoes were submitted to gamma radiation from a source of Cobalt-60 type Gammacell-220 at doses of 0.25, 0.50, and 1.0 kGy and non-irradiated samples, and stored at room temperature during maturation. Analyses of moisture content, ash content, pH, titratable acidity, soluble solids (Brix), ratio (soluble solids/titratable acidity), carotenoids, ascorbic acid - vitamin C, firmness, peel and fleshy mesocarp color - lightness (L*) and Chroma (C*) at 1, 7, 14, 21 and 28 days after irradiation (DAI) were performed. An increase of total carotenoids and weight loss has been observed as the irradiation dose increased over storage time of cherry tomatoes. The firmness of irradiated group of cherry tomatoes was lower than that of control non-irradiated from 7 DAI. Irradiation did not alter the values of ash contents (0.50–0.62%), pH (6.8–7.2), and peel color L* (32–41) of cherry tomatoes compared to non-irradiated tomatoes. The storage periods of cherry tomatoes also were responsible for the differences observed in titratable acidity, total carotenoids, vitamin C, weight loss and firmness; therefore, it was affirmed that the fruits presented behaviors equal to those expected, since during the ripening and senescence period there are changes in the physicochemical characteristics of most fruits. Thus, it was concluded that irradiation up to 1.0 kGy gamma-rays could improve sufficiently the postharvest conservation of cherry tomatoes to satisfy the consumer with acceptable nutritional quality.