Optimizing UV-C irradiation for reducing storage losses in pigeon pea grains by pulse beetle (Callosobruchus maculatus)

Post-harvest losses in pigeon pea (Cajanus cajan) due to insect infestation significantly impact grain quality and shelf life. This study aimed to evaluate the effectiveness of ultraviolet (UV-C) irradiation and optimization of machine parameter and processing time to minimize post-harvest losses. The experiment was laid in Completely Randomized Design with 13 treatments, replicated twice. A custom-designed UV treatment machine was developed to expose grains to UV-C light (254 nm) at varying feed rates (200, 350, and 500 kg/h) and exposure durations (15, 30, 45, and 60 minutes). Treated and untreated (control) grain samples were stored under ambient conditions for six months, and key storage parameters such as moisture content, percent grain damage, and weight loss due to insect infestation were measured at an 15-day interval up 180 DAS period . The results demonstrated that UV treatment significantly reduced storage losses compared to untreated samples. Among the treatments, grains treated at lower feed rates (200 Kg/h) and longer exposure durations (60 min) showed the least insect damage (8.7%) and weight loss (0.9%) after 180 days of storage. The insect damage percentage and weight loss percentage in untreated sample was found high as 46% and 9.3% respectively. The UV treated grains were maintaining a lower moisture level as compared to untreated grains throughout storage period resulting moisture reduction due to UV Irradiation. UV-C irradiation was found to be an effective method for enhancing the shelf life and maintaining the post-harvest quality of pigeon pea grains, offering a promising alternative to chemical storage treatments.