Effect of Selenium Nanoparticles and Aqueous Almond Extract on Isolated Bacteria

Abstract

This study was conducted in the laboratories of the University of Tikrit / College of Agricultural Sciences / Department of Food Industries. The study began in the period 1/10/2022 to 1/6/2023. The study included the preparation of a biofilm of whey proteins combined with selenium nanoparticles (2 w/%) and (4) w/v%) as a coating of biocomposites to estimate the antibacterial effect against both Staphylococcus aureus and E.coli, and the total bacterial count (TBC) in soft cheese samples stored in the refrigerator at 4 °C during 14 days. To reach the goal of the study, the chemical parameters such as the pH value and the physical information that includes the water holding capacity (WHC), as well as the total number of bacteria and colon. In addition to the sensory properties of soft cheese samples without coating (control T1), coated with a biofilm of whey proteins T2, whey protein coatings mixed with selenium nanoparticles (2 w/v %) T3, whey protein coatings mixed with aqueous almond extract at (2 w/v %) T4, whey protein coatings mixed with Se NPs with aqueous almond extract at (2 w/v %) %) T5 The results showed that TBC and the total number of coliforms in samples coated with the mixture of whey proteins and nano-biofilms decreased significantly (P < 0.05), and TBC appeared in 14 days in T1, T2, T3, T4 and T5: 16.34, 15.12, 13.58, 11.28, and 12.84 (CFU.g-1) respectively compared to the number at the beginning of the experiment 8.6 9, 8.80, 8.87, 8.74, and 8.81 (CFU.g-1), respectively. An increase in the amount of ph and the value of TBA was observed with an increase in the storage period in all groups of soft cheese samples, while the rate of increase was significantly lower in the T5, T4 and T3 groups compared to the T2 and T1 groups. The percentage of water retention (WHC) decreased significantly with the increase in the storage period, and the decreasing rate was significantly less in the samples coated with a vital membrane of the spray proteins only and a vital membrane of the spray proteins integrated with the nano-selenium particles, which appeared in 14 days of storage in T2, T3, T4, T5 55.41, 56.71, 58.46 and 57.11 % Completely compared to the T1 53.32 % console. She was. The results of the sensory characteristics evaluation showed that the soft cheese samples coated with whey protein coatings combined with selenium nanoparticles and aqueous almond extract preserved their sensory properties until the end of the storage periods. Similarly, samples coated with a whey protein biofilm for nine days maintained their sensory characteristics. In contrast, the unwrapped samples maintained sensory features for only four days. It was concluded that the antibacterial and antioxidant effect of the mixture of biowhey proteins with selenium nanoparticles and aqueous almond extract enhanced the increase in the preservation periods of soft cheese samples for a period of 14 days inside the refrigerator at 4 °C without any effect on the sensory properties.