Effect of Radiation Processing on the Nutritional Composition of White Lupin (Lupinus albus L.) Seeds

This study investigated the effects of gamma irradiation at different doses on the nutrient composition, fiber fractions, metabolizable energy (ME) values, and antioxidant capacity of white lupin (Lupinus albus L.) seeds. The seeds were exposed to 0 (Control), 100, 200, and 300 Gray (Gy) of gamma irradiation. Proximate composition, starch, sugar, and fiber fractions (crude fiber, NDF, and ADF) were determined using standard analytical methods, whereas ME values for ruminants and poultry were calculated based on the analyzed nutrient contents. Antioxidant activity was assessed using the DPPH radical scavenging assay. The results demonstrated that gamma irradiation induced significant changes in both nutritional composition and functional properties of white lupin seeds. In particular, crude protein and ash contents increased significantly at doses of 200 and 300 Gy, while starch and fiber fractions (crude fiber, NDF, and ADF) decreased markedly. Although ruminant ME values were not significantly affected, poultry ME values increased substantially at 300 Gy. With respect to antioxidant capacity, DPPH radical scavenging activity increased in a concentration-dependent manner across all treatments, with the highest effect observed at 200 Gy. In conclusion, gamma irradiation can be considered a promising processing technique for improving the nutritional value and antioxidant capacity of white lupin seeds. However, further in vivo studies are required to evaluate the effects of different irradiation doses on animal performance, nutrient digestibility, and long-term biological outcomes.