Abstract
This work investigated the effect of gamma irradiation with different doses (0.0, 2.5, 5 and 10 kGy) on some biochemical parameters, antioxidant and antimicrobial activities of two Egyptian dry date fruit genotypes. Reducing sugars (%) were significantly increased to 65.96% and 68.09% at 5 kGy for Sakouti and Bondoky cultivars, respectively. The dose level 5 kGy showed highest total soluble sugars (84.62% and 87.66%) for Sakouti and Bondoky cultivars, respectively. Bondoky cultivar has higher content of glucose and fructose at dose 5 kGy compared with Sakouti cultivar. Significantly sucrose content in both cultivars was decreased by increasing γ-irradiation dose level. Total phenolic and flavonoid contents were significantly increased at 5 kGy. The highest level (82.85%) of scavenging activity (DPPH %) was recorded at 5 kGy by Sakouti cultivar. Gamma irradiation caused a significant increase in antimicrobial activity of both cultivars against bacterial (Gram+ve and Gram-ve) and fungal strains. Antimicrobial activities against Escherichia coli and Enterobacter Cloacae were more pronounced with Sakouti than Bondoky cultivar. Antifungal activity was stronger than the antibacterial for both cultivars. Results concluded that γ-irradiation enhanced phenolic and flavonoids compounds, the antioxidant activity and antibacterial potentials of the studied two Egyptian date palm fruits.