Purification,Structure Identification Of Anthocyanins And Its Antioxidant Activity From Aronia Melanocarpa

Aronia melanocarpa is a native deciduous shrub in the northeastern United States. As a resource both of medicine and food, the fruit also contains extremely rich anthocyanins. Anthocyanins have a powerful antioxidant activity in natural pigments.Aronia melanocarpa introduced from Liaoning Haicheng was used to study its extraction,purification,stability,structure and antioxidant activity. The main conclusions are as follows:The extracting technical condition of anthocyanins was studied by the solvent extraction and the microwave- assisted extraction methods. Under the optimal conditions, the extraction rate of anthocyanins was 0.75 g/100 g by the solvent extraction, and the extraction rate of anthocyanins was 0.79 g/100 g.The resin of HP-20 was selected to purify anthocyanins in five resins, and its dynamics of adsorption and desorption was optimized. The optimal conditions for the purification of anthocyanins using HP-20 resin were determined as follows: 40%ethanol(contains 0.5% acetic acid) as elution solvent,p H 2.0,the adsorption conditions were using 0.6 mg/m L elution solvent,the adsorption and desorption flow rates were 1m L/min.The color scale increased from 14.3 to 121.5 under the optimized purification conditions.The stability experiments showed that anthocyanins exhibited poor stability to sun light,heat,oxidant and reductant.Metal ions of Na+,Fe2+,Zn2+,Mg2+ and Mn2+exhibited little effect on anthocyanins stability.In alkaline environment anthocyanins were completely destroyed. Hence,it was conclude that anthocyanins of Aronia melanocarpa should be stored at low p H and temperature,dark environment,avoided to contact with metal ions.The components of the Aronia melanocarpa anthocyanins were analyzed by UV-Vis,HPLC-DAD and UPLC-MS methods. Four constituent parts of the anthocyanins were identified as follows:cyanidin-3-galactoside(68.68%),cyanidin-3-glucoside(5.28%),cyaniding-3-arabinoside(25.62%),cyaniding-3- xyloside(0.42%).The total and its four constituent parts antioxidant capacity was investigated respectively. The antioxidant activity of the anthocyanins decreased in the order of cyanidin-3-galactoside > all anthocyanins > cyaniding-3-arabinoside >cyanidin-3-glucoside. The antioxidant activities of the anthocyanins were all higher than Vitamin C. The result of scavenging the superoxide anion and DPPH were similar to antioxidant capacity.The effect of anthocyanins of Aronia melanocarpa on apoptosis induced by UVA radiation was investigated. The results showed that the optimum concentration of anthocyanins was 125 μg/m L. The cell secretion of MMP-1 decreased to 60.2%compared to the control group under this condition.