Radiação ultravioleta no controle pós-colheita de colletotrichum gloeosporioides em uva 'niagara rosada

Abstract

Most of the postharvest losses of 'Niagara Rosada' grapes are caused by rot and detached berries. Recently, many researches on alternative methods, such as physical treatments, have been carried out in order to control rots and extend the shelf life of fruits. The objective of this research was to evaluate the effect of ultraviolet radiation (UV-C) on the control of C. gloeosporioides in 'Niagara Rosada' grapes stored at room condition and under refrigeration. Clusters of 'Niagara Rosada' grapes were inoculated with the pathogen and submitted 2 hours later to different doses of UV-C, 0, 1.05, 2.09, 4.18, and 8.35 kJ m-2, during the periods of 0, 1, 2, 4, and 8 min, respectively. Then, the clusters were stored under two conditions: 25±1 °C/80±5% RH for 7 days, and at 1±1 °C/90±5%RH for 16 days followed by storage at 25±1 °C / 80±5%RH for 5 more days. The grapes were evaluated for rot incidence, stem browning, color of the berries, percentage of detached berries, titratable acidity, total soluble solids, and ratio. It was observed that UV-C radiation was effective in reducing the incidence of C. gloeosporioides on inoculated 'Niagara Rosada' grapes and did not change the physicochemical characteristics of the grapes.