Application of UV irradiation in preserving Canh oranges (Citrus reticulata)

Abstract

Canh orange (Citrus reticulata) is one of the favourite orange varieties in Vietnam due to its high flavour and nutritional value. However, Canh oranges have a short shelf life and are prone to spoilage after harvest, leading to significant economic losses. The application of UV technology in post-harvest preservation is a promising method that helps prolong the shelf life by its antibacterial effects and the removal of ethylene gas. In this study, oranges were irradiated with UV light (254 nm) for 30 minutes (20.6 kJ/m²), then stored at 4^oC. The results indicated that the UV-irradiated oranges showed improvements in fruit quality and shelf life. Specifically, after 4 weeks of storage, 90% of the oranges remained unspoiled, and the natural weight loss rate of Canh oranges is very low. Additionally, the fruit still maintained its sensory properties with a total sensory evaluation score of 16.5, indicating a good quality level, the loss of vitamin C was also significantly lower compared to orange samples that were only stored in cold conditions and the control sample. Thus, the UV irradiation method combined with cold storage can extend the shelf life of Canh oranges up to 4 weeks, ensuring economic efficiency because the mass loss is less than 10%, and the quality and appearance are maintained.