响应面试验优化石榴皮多酚提取工艺及石榴不同部位多酚的抗氧化活性分析

以石榴皮为原料，通过单因素试验及响应面试验优化石榴皮多酚的最佳提取工艺条件为：乙醇体积分数40%、超声波功率250 W、浸提温度60 ℃、料液比1∶27.5（g/mL）、超声时间39.3 min。此工艺条件下的多酚提取量为（1.13±0.26）mg/g。在优化条件下分别对石榴皮、石榴瓤和石榴籽中的多酚类化合物进行提取并比较其抗氧化活性，得到石榴不同部位的抗氧化活性大小依次为石榴皮＞石榴籽＞石榴瓤；进一步研究了人工模拟胃肠液对抗氧化活性最强组分石榴皮多酚活性的影响，发现经人工胃液处理后，石榴皮多酚的抗氧化活性升高（P＜0.05），而经人工肠液处理后其抗氧化活性降低（P＜0.05），推断石榴多酚类化合物在模拟胃肠液条件下其结构和功能的变化是不同的。

Optimization of Extraction Process of Polyphenols from Pomegranate Peel by Response Surface Methodology and Antioxidant Activity Analysis of Polyphenols in Different Parts of Pomegranate Fruit

The ultrasonic-assisted extraction of polyphenols from pomegranate peel was optimized through the combined
use of single factor method and response surface methodology. The optimal extraction parameters were found as follows:
ethanol concentration, 40%; ultrasonic power, 250 W; extraction temperature, 60 ℃; material/liquid ratio, 1:27.5 (g/mL);
and extraction time, 39.3 min. The yield of polyphenols was (1.13 ± 0.26) mg/g under these conditions. Polyphenols
compounds were extracted from the peel, pulp or seed of pomegranate under the optimal conditions, and their antioxidant
activities were evaluated and compared. The results showed that the antioxidant activity of different fruit parts of
pomegranate was in the decreasing order: peel > seed > pulp. The present study also found that after treatment with artificial
gastric fluid, the antioxidant activity of pomegranate peel was significantly increased (P < 0.05) but was significantly
decreased after treatment with artificial intestinal fluid (P < 0.05). The results suggested that the changes in the structure and
function of polyphenols in artificial gastric and intestinal fluids were different.