Design of 222 nm UV-C experimental device and experiment on the effect of radiation on the quality of post-harvested fresh tomatoes.

To investigate the effect of safe and green 222 nm UV-C irradiation on the sterilization, disinfection, and storage characteristics of fresh tomatoes, a new 222 nm UV-C irradiation experimental device was developed. Firstly, in an effort to improve the irradiation efficiency and service life of the lamp tube, a lamp with an active convection heat transfer system, parabolic reflector, and adjustable irradiation parameters was designed. Furthermore, a tomato tray capable of reciprocating motion was made to promote uniform UV-C irradiation on tomatoes. Then, a study was conducted on the effect of UV-C irradiation on the storage quality of fresh tomatoes. The results showed that 222 nm UV-C irradiation at 4 kJ/m2 could slow down the softening, promote the accumulation of lycopene, total phenolics, and flavonoids of tomatoes during storage. Which also improved the activity of antioxidant enzymes of catalase, superoxide dismutase, ascorbate peroxidase and glutathione reductase, enhanced the antioxidant capacity of tomato fruits. Furthermore, UV-C irradiation treatment also reduced the degree of fungal decay in tomatoes. At the same time, the experimental results also confirmed that the designed reciprocating tomato tray can improve the uniformity of tomato irradiation. It is of great significance for improving the irradiation effect and efficiency of tomatoes.