నైరూప్య

Extract optimization of apple flavonoids by RSMand study on •OH scavenging effect

LiHui-Duan

Ethanol extraction of total flavonoids from Zhao tong Golden Delicious Apples were researched in the paper. The response surface methodology (RSM) and Box-Benhnken Design (BBD) were employed to optimize the extraction process. Based on the single-factor experimental results, ethanol concentration of 65~85%, solid-liquid ratio of 15:1~25:1mL·g-1, extraction temperature of 55 ~ 75°Cand time of 1.5 ~ 2.5h were selected as the independent variables and scope for BBD. Hydroxyl radicals scavenging effect of Apple extracts were also measured. The optimum extract conditions were ethanol concentration of 72%, solid-liquid ratio of 20:1mL·g-1, extraction temperature of 65ï‚°C and extraction time of 2.3h with responding extraction ratio of 5.63% for pericarp, 4.30% for fruit and 3.89% for Pyrenes. The experimental extraction ratios matched well with the theoretical values by solving the multiple regression equation, which confirms that RSM could be successfully used to optimize the extraction process and the fitted quadratic model had a predictive effect on target extracts. The scavenging effect of apple extracts on hydroxyl radicals displayed a significant dose-effect relationship, however, it showed a weaker scavenging effect compare to BHT with the same concentration.