橙皮果胶多糖的绿色提取、理化性质及生物活性分析

Green Extraction, Physicochemical Properties, and Biological Activity Analyses of Pectin Polysaccharides from Orange Peel

摘要:

为有效利用废弃橙皮资源并提高水果产品的附加值，该研究以不同pH值的柠檬酸/柠檬酸钠缓冲溶液绿色提取橙皮果胶，并对其理化性质和生物活性进行分析。结果显示，提取的果胶得率在13.1%至36.3%之间，平均半乳糖醛酸含量为75.81%，平均酯化度为26.67%。橙皮果胶还表现出良好的抗氧化与胆汁酸结合能力，研究结果表明，10 mg/mL的果胶对•OH、DPPH•和ABTS+•的清除率分别为95.14%、49.62%和38.39%；高分子量的果胶对胆汁酸具有较高的结合能力。与Ca2+结合能力实验结果表明，萃取剂pH值为12条件下提取的果胶具有最佳的凝胶形成能力。流变学结果表明其形成的凝胶主要为弹性材料，在角速率0~250 rad/s范围内所有样品的储存模量（G′）均大于损耗模量（G″）。最后，果胶对丁酸梭菌益生活性实验结果表明，提取的果胶可作为碳源促进肠道益生菌生长，且具有良好的酸化能力。综上所述，以该方法提取的橙皮果胶可直接获得低酯果胶，且生物活性显著。因此，橙皮果胶在提高水果产品附加值和促进营养保健领域具有潜在的应用前景。

Abstract:

To effectively utilize discarded orange peel as a resource and enhance the value of fruit products, we extracted pectin from orange peel using eco-friendly citric acid-sodium citrate buffer solutions at different pH values, then analyzed the physicochemical properties and biological activities of the extracted pectin. Pectin yield ranged from 13.1% to 36.3%, with an average galacturonic acid content of 75.81% and an average esterification degree of 26.67%. Orange peel pectin exhibited good antioxidant and bile acid binding capacity, with scavenging capacity of 95.14% for •OH, 49.62% for DPPH•, and 38.39% for ABTS+• at a concentration of 10 mg/mL. High-molecular-weight pectin demonstrated elevated bile acid binding ability. A Ca2+ binding assay revealed that pectin extracted at pH 12 exhibited optimal gel-forming ability. Rheological analysis indicated that the formed gel was predominantly elastic, with storage modulus (G′) higher than loss modulus (G″) across all samples at 0 to 250 rad/s. Finally, a probiotic viability assay using Clostridium butyricum demonstrated that the extracted pectin can promote intestinal probiotic growth and has good acidification capacity. Overall, the pectin obtained by this extraction method can directly be used as low-ester pectin, and exhibits significant biological activity. Orange peel pectin thus offers potential applications that enhance the value of fruit products and promote nutritional health.