Purification And Antioxidant Activity Of Pigment From Purple Sweet Potato In Diabetic Rats

In this study the purifying anthocyanins from purple sweet potato(APSP) for the first time as raw material;studied that method and technology of purifying APSP for the second time by cation exchange resin;compared the stability of APSP between before and after purification under different environmental conditions;determined the modulatory effect of after purification APSP on blood glucose,the level of blood fats and activities of antioxidant defense systems in streptozotocin-induced diabetic rats.The results of studies as follows:D061 resin can be used in the technological process of purifying APSP for the second time.The technological condition as the following:the pH value is at 2.6,the concentration of APSP is around 0.6×100(optical density),the velocity to ascend sample is 1.0 BV/h,the elution is 50%ethanol(with 2%HCl),the velocity to elute is 0.5 BV/h.Under this technological condition,the product yield of APSP is 82.99%.Finally,the concentration of APSP is above 29.38%,and the color scale is above 136.80 through purifying treatment by D061 resin.The second purifying APSP had spectral characteristics of the general anthocyanin pigment.The color of anthocyanin solution was bright red at pH 3.0 and the resistant to heat and the light was lower to the before purification APSP;Fe³⁺,H₂O₂,Na₂S₂O₅ and Vc can decompose it by oxidization;low concentration of Benzoic Acid and Potassium sorbate have little influence on the stability of APSP;The light absorbency of APSP solution increased after added Mn²⁺,Mg²⁺,Cu²⁺and other metalline hydronium and organic acid, sucrose,dextrose and salt.Diabetic rats vas induced following overnight fasting by an tail mainline injection of streptozotocin in a single dose,after the inducement of diabetes,the diabetic rats behaved worse and worse,their blood glucose increased significantly,the level of blood fats was out of the way and the activities of antioxidant defense systems was destroied;APSP treatment improved behavior and lowered the blood glucose evidently;the concentration of TG,TC and LDL-C in serum was decreased,the concentration of HDL-C was incresaed;in serum and tissue,the concentration of MDA was decreased and the activities of T-AOC,SOD, CAT and others were increased.In addition,diabetic rats showed an obvious decrease in the number ofβcells in pancreas,but the pancreas of APSP-treated rats were imporved the number ofβcells were significantly increased,the APSP second team has the better effects, amd corresponded the diabetic-metformin-supplemented.