Nutritional and Physiological Effects of Postharvest UV Radiation on Vegetables: A Review.

Effective ultraviolet (UV) irradiation has been used as a postharvest technology to reduce decay, delay ripening, and delay senescence in crop products. In this review, the effects of UV radiation of different wavelengths and doses on physiological and phytochemical parameters in postharvest vegetables are discussed in summary, including appearance (color and texture), microbial load, respiration rate, enzymatic antioxidant system, and various bioactive compounds (phenolic compounds, carotenoids, chlorophylls, vitamins, glucosinolates, betalains, and antioxidant activities). In particular, postharvest UV radiation affects oxidative metabolism and increases the antioxidant activity of plant products, which could help delay yellowing and senescence of vegetables, trigger defense responses, and reduce decay and diseases. In some cases, irradiation stimulates the synthesis of bioactive secondary metabolites that may improve the nutritional value of vegetables. The findings presented in this review are very useful and valuable for the preservation and improvement of the nutritional quality of vegetables after harvest. It will also provide scientific support for industrial and commercial applications of UV radiation in postharvest.