Effect of gamma irradiation on the physicochemical properties and nutrient contents of peanut

This study aims to assess the effect of gamma irradiation on the physicochemical properties and nutrient contents of two different peanut cultivars. The peanuts were treated with 0, 1, 3, 5, and 10 kGy gamma irradiation doses. The examined physicochemical properties were water activity, fatty acid value (FAV), peroxide value (PV), carbonyl value (CV), malondialdehyde (MDA) content, and lipase activity. The examined nutrient contents were moisture and ash contents, total sugar, protein and fat contents, fatty acid and amino acid composition. Results showed that high irradiation dose (10 kGy) significantly decreased the fat and protein contents and increased the water activity of peanut. However, the moisture and ash contents and total sugar were not affected by irradiation. The FAV, PV, CV, and MDA contents increased depending on the radiation dose. Fatty acid and amino acid composition changed when the irradiation dose increased. Sodium dodecyl sulfate polyacrylamide gel electrophoresis analysis revealed that irradiation did not modify the protein subunits but disrupted the disulfide bonds. Furthermore, lipase activity decreased with the increased irradiation dose. This phenomenon may positively affect peanut quality during storage.