Influence of postharvest UV-C illumination on biochemical properties of green beans

Abstract

In this study, harvested green beans (Phaseolus vulgaris cv. Bourgondia) were subjected to different doses of UV-C illuminations (0.1, 0.3, 0.5 kJ m − 2; low, medium, and high dose, respectively) and stored under modified atmosphere packages (MAP) at 8°C for 25 days. The extension in storage time resulted increase in weight loss, fluctuations in TSS content, and respiration rate. Medium and high doses resulted higher total phenolic contents comparing to control and low dose treatments. No UV-C damage or deterioration was detected during the entire cold storage period, however medium and high doses caused damages to the surface at the beginning 15 days cold storage plus 3 days shelf life (15 d CS plus 3 d SL) period. All doses also resulted in lower respiration rates and higher total sugar content than control. The effects of illumination on reducing sugar and total chlorophyll contents were non-significant. There were no significant effects on antioxidant activity in cold storage, however during shelf-life the high UV-C dose had highest antioxidant activity compared to control and other doses. Low dose had positive effects on the edible quality and maintained the postharvest quality of green beans for 25 days. Our findings showed that low UV-C dose can be recommended commercially to maintain quality of green beans with no surface damage among the UV-C illumination doses tested.