The Extraction Process Of Ethanol-Soluble Substance From Degummed Sunflower Disk And Its Antioxidant Activity

In our district,a large number of sunflower disks are produced every year.Used as raw materials,the sunflower disks produce pectin.However,the by-product degummed sunflower disk residue produced after the production of pectin is incinerated,and the nutrients other than pectin are not fully utilized.For this reason,in this paper,the degummed sunflower disk residue was used as raw material,and the alcohol soluble matter was extracted by ultrasonic assisted extraction method to study its antioxidant activity and its protective effect of hydrogen peroxide(H2O2)on oxidative damage of human umbilical vein endothelial cells(Human umbilical vein endothelial cells,HUVECs).The main findings are as follows:(1)The degummed sunflower disk residue was used as raw material to extract alcohol soluble matter.The extraction rate and DPPH free radical scavenging rate were used as indicators.The optimal extraction process was determined by orthogonal experiment.The results showed that the optimum extraction conditions were as follows:ratio of material to liquid 1:17 g/mL,ethanol concentration 70%,ultrasonic treatment time 30 min,extraction temperature 600C,extraction time 1 h.Under such process condition,the extraction rate was 20.32%,and the DPPH free radical scavenging rate was 72.13%.(2)By analyzing the composition of the alcohol extract obtained under the optimal process conditions,it was found that the main components were protein,polysaccharide,polyphenol(as gallic acid content)and flavonoid(as rutin content),and the content was 18.88%,3.11%,5.36%and 10.04%,respectively.(3)The antioxidant activity of the alcohol extract of the degummed sunflower disk was studied,using the total reducing power,DPPH free radical scavenging rate,hydroxyl radical scavenging rate and ABTS free radical scavenging rate as indices.The results showed that the total reducing power increases with the increasing concentration.When the concentration reached 1.6 mg/mL,the total reducing power was close to Vc-The DPPH free radical scavenging rate of the alcohol extract increased with the increasing concentration.When the concentration reached 1.6 mg/mL,the DPPH free radical scavenging rate was close to Vc.The hydroxyl radical scavenging rate of alcohol extracts does not change significantly with the increasing concentration,and the hydroxyl radical scavenging rate was lower than Vc.The ABTS free radical scavenging rate of alcohol extracts increased with the increasing concentration,but the ABTS free radical scavenging rate was lower than Vc.The above results indicated that the hydroxyl radical scavenging rate and ABTS free radical scavenging rate of the degummed sunflower disk extract were lower than Vc,but the total reducing power and DPPH free radical scavenging rate were comparable to Vc,indicating that it had certain antioxidant activity.(4)The protective effect of alcohol extracts from degummed sunflower leaves on H2O2-induced HUVECs cell injury was further studied.It was found that when the concentration of alcohol extract was 3.125,6.25,12.5 ?g/mL,it promoted the growth of normal HUVECs cells.When added with alcohol extracts at concentrations of 3.125,6.25,and 12.5?g/mL,the H2O2-induced HUYECs cell activity increased with the increasing concentration.Compared with the normal group,the SOD and GSH-Px activities in H2O2-induced HUVECs cell oxidative damage model group were significantly reduced,and LDH activity and MDA content were significantly increased.When added with alcohol extract at concentrations of 3.125,6.25,12.5 ?g/mL,the activity of SOD and GSH-Px increased significantly with the increasing concentration,while the activity of LDH and MDA decreased significantly.The results showed that the alcohol extract of degummed sunflower leaves had protective effects on H2O2-induced oxidative damage of HUVECs by increasing SOD and GSH-Px activities,decreasing LDH activity and MDA content.