Extraction Of Antioxidant Components From R.Setate×R.Rugosa And Antioxidant Capacity

R.Setate×R.Rugosa is a hybrid plant and have a Large-scale cultivation in Yong deng country of Gansu province. The biological characteristics is cold-resistant, drought-enduring, pest resistance, adaptable and more tolerance to poor soil.In the study, a central composite design was employed to optimize the extraction conditions of antioxidant components from R.Setate×R.Rugosa by ethanol with four factors:ethanol concentration, the ratio of liquid to solid, temperature and extraction time. And the combined effect of these variables on total antioxidant power were investigated. Results showed that the generated regression models adequately explained the data variation and significantly represented the actual relationship between the independent variables and the responses. The results indicated that the effect order of four factors was as follows: temperature, liquid to solid, ethanol concentration and time. The canonical analysis revealed that the optimal conditions for extraction were: ethanol concentration 50%, the ratio of liquid to solid 25:1, temperature 90℃, time 120min. Under optimal conditions, the predicted value of the total antioxidant capcity was 3365μmol·g-1,the testing value was 3343.9μmol·g-1,and its relative error was 0.63%. There were no obvious difference between the testing value and theoretic values from regressionn equation and the regression model was fitted well.At the same time, the mainly antioxidant componets was determined, such as flavonoids and total phenolic and compared with Rosa Damascena.It show that,both of their content in the extractions of R.Setate×R.Rugosa are more higher than Rosa Damascena.To study the scavenging effect of extracts of R.Setate×R.Rugosa and Rosa Damascena on DPPH ? free radical ,active oxygen radical and hydroxyl free radical.The results show ,with the increase of extract concentration that all free radical scavenging ability had increased.The petal of R.Setate×R.Rugosa have the best scavenging effect on the hydroxyl free radical and scavenging effect on DPPH·free radical, the EC50 value of hydroxyl free radical and the DPPH free radical were 6.21mg/ml and 10.89μg/ml, respectively.The dregs of R.Setate×R.Rugosa have the best effect on active oxygen radical and EC50 value of active oxygen radical was 13.43 mg/ml;The different parts extraction of R.Setate×R.Rugosa and Rosa Damascena was studied and the antioxidant activity of the extracts on lard was evaluated as well. When the concentration of the extractions were increased that the antioxidative effect was increased too. When the concentration of rose petals in lard was 0. 25%, it have the best antioxidant effect and keep increasing the concentration of rose petals that the antioxidant effect hasn't increased anymore. The concentration of rose petals in lard was 0. 5%, the antioxidative effect was as good as 0. 02% ascorbic acid ,but the 0.5% rose petal is more stable than VC. Add VE dose not inhibit lard autoxidation rate,but it may promote the lard oxidation. Inhibit lard autoxidation rate of synthetic antioxidants were better than rose petals, BHT is better than TBHQ.Inhibit lard autoxidation rate of different parts extraction from R.Setate×R.Rugosa and Rosa Damascena were : 0.50% the petal of R.Setate×R.Rugosa>0.50% the dregs of R.Setate×R.Rugosa>0.25%the dregs of R.Setate×R.Rugosa>0.50% the petal of Rosa Damascena>0.25% the petal of R.Setate×R.Rugosa>0.25% the petal of Rosa Damascena .