Study On The Preparation Characterization And Antioxidand Function Of Casein-Phosphopeptides Na₂SeO₃

The thesis extracted Casein non-phosphopeptides from commercially available Casein, researched optimum conditions of the binding reaction between CNPPs and Na2SeO3 to obtain high selenium content Casein non-phosphopeptides Na2SeO3. It used the combined method of Hydride generation-atomic fluorescence spectroscopy (HG-AFS), Transmission electron microscopy(TEM) and Infrared Spectroscopy(IR) to analysis the representarion of Casein non-phosphopeptides Na2SeO3 and used Total Antioxidant Capacity (TEAC) method to get a preliminary determination of Casein non-phosphopeptides Na2SeO3 and also verified its antioxidant capacity by animal test. At the same time, it explored Casein non-phosphopeptides Na2SeO3’s effects on three conventional indicators of of mice,which is body weight, organ index and hematological parameters.Test One:Preparation of Casein non-phosphopeptides Na2SeO3. Use Alcalase to hydrolyze Casein to get the mixture of CNPPs and CPPs, separate and extract CNPPs by ethanol precipitation of calcium, use selenium content as reference index to study the binding reaction conditions of CNPPs and Na2SeO3, which first to determine the the three factors (the reaction time, temperature, pH) on the best affecting scope of the selenium content, and then determine the optimal reaction conditions by orthogonal test which was reaction time 2 h, the reaction temperature 60℃, the reaction pH 7. Under this condition, the selenium content of the obtained Casein non-phosphopeptides Na2SeO3 was 3.28 mg/g.Test Two:A preliminary study of Casein non-phosphopeptides Na2SeO3 characterization. By observing the changes of Na2SeO3 and CNPPs’s color before and after reaction and using combined method of TEM analysis and ER test to study the representation of Casein non-phosphopeptides Na2SeO3. The results showed that, under heating conditions the chemical bond of CNPPs and Na2SeO3 migrated, the molecule rearranged and generated the new material which was the Na2SeO3, which was red nanoscale particles having a diameter size remaining at 45 nm or so.Test Three:Research on Casein non-phosphopeptides Na2SeO3 antioxidant capacity. The improved rate of TEAC could achieve 57.70% before and after reaction between CNPPs with Na2SeO3, which showed significant synergistic antioxidant capacity of CNPPs and Na2SeO3. During animal experiments, it fed mice with different doses of Casein non-phosphopeptides Na2SeO3 regularly everyday. The test mice were divided into casein peptide non-phosphorus Na2SeO3 group (suitable dose group, dose-critical groups), Na2SeO3 group (suitable dose group), yeast selenium group (suitable dose group) and conventional diet group depending on the type and dose of selenium of fed sample. Contracting with Na2SeO3 group, yeast selenium group and conventional diet group, it used the level of SOD, GSH-PX,T-AOC, MDA and GSH as a test indicator to study the role of Casein non-phosphopeptides Na2SeO3 on mice in terms of anti-oxidative capacity.The results showed that, Casein non-phosphopeptides Na2SeO3 revealed better antioxidant capacity than other selenium reagents.Under the premise of the same dose, the male mice’s which was supplemented with Casein non-phosphopeptides Na2SeO3 revealed significant difference in T-SOD, GSH-Px and T-AOC.With the increase of Casein non-phosphopeptides Na2SeO3-s doses, the body’s antioxidant enzyme activity and antioxidant capacity increased significantly.Test Four:Study the effect on body’s selenium supplementation of Casein non-phosphopeptides Na2SeO3. During animal experiments, it tested several conventional indicators of body weight in mice, organ index, red blood cell count (RBC), hemoglobin concentration (Hb), white blood cell count (WBC), hematocrit (HCT) and platelet count (PLT) to explore the Casein non-phosphopeptides Na2SeO3’s selenium supplementation effect on mice. The results showed that Casein non-phosphopeptides Na2SeO3 selenium supplementation had a significant effect on the growth performance of mice, liver and kidney index index. But it had no significant effect on the index of mouse heart, lung, spleen, hematology, and female mice’s index of mouse heart and lung. It also showed that Casein non-phosphopeptides Na2SeO3’s critical dose could significantly improve index of male mouse’s heart and lung,but suitable dose group had no significant impact.