百香果果皮总黄酮的超声波辅助提取工艺优化及其性质研究

本文优化百香果果皮总黄酮的超声波辅助提取工艺,并评价其稳定性及抗氧化活性。在单因素实验结果的基础上,采用响应面法对提取工艺进行优化。考察总黄酮提取液的吸光度值随温度、光照等条件的变化情况,研究其稳定性;以对·OH、NO₂^-清除率及总抗氧化力为指标衡量总黄酮的抗氧化活性。结果表明:百香果果皮总黄酮的最佳提取工艺为乙醇浓度61%,液料比59:1 mL/g,提取温度56℃,超声功率240 W,提取时间25 min,在此条件下总黄酮提取率可达2.19%±0.03%,与回归模型预测值2.21%(<1%)相当,说明该工艺合理、可行。百香果果皮总黄酮在60℃以下黑暗环境中具有较高的稳定性,高温和紫外线对其则具有较大的破坏效果。抗氧化活性测试表明百香果果皮总黄酮的抗氧化能力与其浓度成正比,当总黄酮浓度为30 μg/mL时,对·OH、NO₂^-的清除率分别为81%、43%,总抗氧化力为0.687。综上所述,百香果果皮总黄酮具有较强的抗氧化能力,但其生物活性易被高温和紫外线破坏因而应低温避光保存。

Optimization of Ultrasonic Wave Assisted-Extraction of Total Flavonoids in Passion Fruit and Their Properties

This study aimed to explore the optimal ultrasonic wave-assisted extraction of total flavonoids in passion fruit and evaluate its stability and antioxidant activity. Based on the results of single factor experiments,extraction process was optimized by response surface methodology. The stability of total flavonoids was studied by investigating the influence of temperature and light on the absorbance of the flavonoid extract. And the antioxidant activity of total flavonoids was assessed by scavenging assays of ·OH,NO₂- and total antioxidant power. The optimal extraction conditions were obtained as follows:Ethanol concentration 61%,liquid-material ratio 59:1 mL/g,temperature 56℃,ultrasonic power 240 W,ultrasonic time 25 min. Under the optimal conditions,an average extraction rate of 2.19%±0.03% was obtained,which was similar to the expect yield 2.21% of the regression model. The total flavonoids in passion fruit peel was stable blew 60℃ under dark. High temperature and ultraviolet light had a destructive effect on it. Investigation on antioxidant activity showed that the clearance rates on ·OH,NO₂- were 81%,43% when the flavonoid concentration was 30 μg/mL and total antioxidant power was 0.687,which would be stronger with higher concentration. Based on the above research results,the optimal extraction conditions are stable and feasible,and the total flavonoids should be kept at low temperature and protected from light to keep its strong antioxidant activity.