Effect of radiation intensity on the outcome of postharvest UV-C treatments

COTE, SANDRA P; RODONI M.L; MICELI E.; CONCELLÓN A.; CIVELLO P.M.; VICENTE, A.R

POSTHARVEST BIOLOGY AND TECHNOLOGY

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2013 p. 83 - 89

0925-5214

Studies on the use of UV-C radiation of fresh produce have focused on the selection of appropriate doses(energy per unit area) for different commodities, but little attention has been placed on the effect ofradiation intensity (dose per unit time). In this study, tomatoes (Solanum lycopersicum cv. Elpida) andstrawberries (Fragaria × ananassa cv. Camarosa), were harvested (breaker and 100% of surface red colorrespectively) and treated with 4 kJ/m2 of UV-C, at low (3 W/m2) or high (33 W/m2) radiation intensities.Untreated fruits were used as controls. After the treatments and at different storage times the incidence ofpostharvest rots and the changes in fruit physical and chemical properties were determined. UV-C treat-ments reduced decay, with the effects being were more marked in fruit exposed to high intensities. Moldcounts were unaffected by the treatments, suggesting that improved disease control did not result fromgreater germicide effect. In both fruit species exposure to UV-C radiation delayed ripening, evidencedas lower color development, pigment accumulation and softening. UV-C-treated fruit maintained betterquality than the control. In strawberry, high intensity treatments were more effective to prevent dete-rioration than in tomato where the differences between UV-C treatments were subtler. Soluble solids,titratable acidity and ethanol soluble antioxidants were not affected regardless of the UV-C intensity.Consumer tests showed higher preference of fruit treated at high UV-C intensity. Results show that inaddition to the applied dose, radiation intensity is a main factor determining the effectiveness of UV-Ctreatments and should not be over-sighted. For a given dose, increasing radiation intensity may in somecases maximize the benefits of UV-C on fruit quality, while significantly reducing the treatments time.