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.