油用牡丹籽种皮多酚的提取及抗氧化和体外发酵特性

Extraction of Polyphenols from Oil Peony Seed Coats and Their Antioxidant and in Vitro Fermentation Characteristics

摘要:

采取超声辅助提取油用牡丹籽种皮中的多酚，以多酚提取量为测定指标，通过单因素试验及响应面分析获得最优的工艺条件，进一步测定牡丹籽种皮多酚的抗氧化活性和体外发酵特性。结果表明，超声波提取牡丹籽种皮多酚的最优工艺参数为：乙醇体积分数60%、料液比1:40、超声功率为480 W，提取时间50 min，多酚提取量为83.11 mg GAE/g。牡丹籽种皮多酚的DPPH、ABTS+自由基清除以及FRAP的IC50分别为8.19、5.83、16.46 mg GAE/g，具有良好的抗氧化活性。体外发酵试验证明，牡丹籽壳多酚均可降低正常组和肥胖组中发酵液的pH值，增加短链脂肪酸含量，且对肥胖组的影响更加明显。这表明从油用牡丹籽种皮中分离的多酚具有明显的体外抗氧化活性，有降低肠道体外发酵液pH值，增加短链脂肪酸的功效。

Abstract:

Ultrasonic-assisted extraction of polyphenols from oil peony seed coats (OPSCP) was conducted, and the extraction yield was used as an evaluation index to optimize extraction conditions through single-factor experiments and response surface analysis. In addition, the antioxidant activity and in vitro fermentation characteristics of OPSCP were determined. The results showed that the optimal conditions of ultrasonic-assisted extraction of OPSCP are as follows: ethanol 60% V/V, solid-liquid ratio of 1:40, ultrasonic power of 480 W, and extraction time of 50 min. The polyphenol extraction yield equaled 83.11 mg GAE/g under the optimal conditions. The IC50 of DPPH, ABTS+ radical scavenging rate, and FRAP values of OPSCP in DPPH, ABTS, and FRAP assays were 8.19 mg GAE/g, 5.83 mg GAE/g, and 16.46 mg GAE/g, respectively, indicating good antioxidant activity. In vitro fermentation experiments showed that OPSCP can reduce the pH of the fermentation broth and increase the content of short-chain fatty acids (SCFAs) for both the normal and obese groups, with a more pronounced effect observed in the obese group. This study indicates that the polyphenols from oil peony seed coats exhibit significant in vitro antioxidant activity and have the effect potential to lower the pH and increase SCFAs in intestinal fermentation broth in vitro.