金柚柚皮多甲氧基黄酮化合物的提取分离及其油脂抗氧化稳定性

Extraction and Isolation of Polymethoxylated Flavonoids from Pomelo Peels and the Antioxidant Stability of Its Oils

摘要:

该研究采用超声辅助结合大孔吸附树脂及制备液相色谱法对金柚柚皮中的多甲氧基黄酮（Polymethoxy Flavonoids，PMFs）物质进行提取分离，通过液相色谱-质谱（LC-MS）分析柚皮PMFs组分，结果表明：金柚柚皮中含有5种PMFs，分别为川陈皮素、橘皮素、3,5,6,7,8,3',4'-七甲氧基黄酮、5-羟基-3,6,7,8,3',4'-六甲氧基黄酮和5-羟基-3,3',7,8-四甲氧基-4',5'-亚甲二氧基黄酮，含量分别为5.12%、4.29%、4.33%、4.10%和3.07%。金柚柚皮PMFs提取物活性实验表明，在质量浓度达到2 mg/mL时，对DPPH、ABTS+自由基清除率最大分别为75.90%、78.85%；在APPH诱导的红细胞溶血模型中，与APPH组80.20%相比，0.05 mg/mL PMFs溶血率显著下降为48.89%；柚皮PMFs提取物对180 ℃，油炸1~5 h油饼中的油脂有抗氧化作用，与空白组（过氧化值0.16~0.28 g/100 g，酸价0.36~ 1.42 mg/g，茴香胺值4.49~7.08）相比，添加面粉质量分数1.00%的柚皮PMFs提取物的理化指标变化量较小（过氧化值0.15~0.19 g/100 g，酸价0.34~1.25 mg/g），添加面粉质量分数0.50% PMFs使油脂茴香胺值（AV）明显下降（茴香胺值0.91~5.50）。综上所述，金柚柚皮中含有5种PMFs，且对自由基有一定的清除效果还具有显著的抑制油脂氧化作用。

Abstract:

Polymethoxylated flavonoids (PMFs) were extracted from pomelo (Citrus maxima) peels and separated using ultrasound-assisted technology combined with macroporous adsorption resins and preparative liquid chromatography. The PMF components were then analyzed by liquid chromatography-mass spectrometry (LC-MS). The results showed that pomelo peels contained five types of PMFs: citrin, tangerine, 3,5,6,7,8,3ʹ,4ʹ-heptamethoxy flavonoid, 5-hydroxy-3,6,7,8,3ʹ,4ʹ-hexamethoxy flavonoid, 5-hydroxy-3,3ʹ,7, 8-tetramethoxy-4ʹ, and 5ʹ-methylenedioxy flavonoid, with their contents being 5.12%, 4.29%, 4.33%, 4.10%, and 3.07%, respectively. Furthermore, when the PMF concentration reached 2 mg/mL, DPPH and ABTS+ free radicals showed maximum scavenging rates of 75.90% and 78.85%, respectively. In the APPH-induced RBC hemolysis model, the hemolysis rate was significantly reduced from 80.20% to 48.89% with 0.05 mg/mL PMFs. In addition, the PMF extract of pomelo peels had an antioxidant effect on oils and fats in oil cake fried at 180 ℃ for 1~5 h. Compared with the blank group (peroxide value of 0.16~0.28 g/100 g, acid value of 0.36~1.42 mg/g, anisidine value of 4.49~7.08), the physical and chemical indices of the PMF extract from pomelo peels with 1% flour content showed little change (peroxide value (0.15~0.19 g/100 g) , acid value (0.34~1.25 mg/g), whereas the lipid anisidine value (AV) decreased significantly with 0.5% flour content of PMFs (anisidine value 0.91~5.5). In conclusion, the five types of PMFs in pomelo peels have an optimal scavenging effect on free radicals and exhibit resistance towards lipid oxidation.