低共熔溶剂提取天麻多糖的工艺优化及其抗氧化活性分析

Optimization of extraction process with deep eutectic solvents and analysis of antioxidant activity of Gastrodia elata polysaccharides

摘要:

为了探究天麻多糖的最佳提取工艺及其抗氧化活性，为天麻多糖提取和开发应用提供理论参考，本研究以天麻为原料，采用超声辅助低共熔溶剂提取多糖，通过单因素实验和响应面实验获得最佳提取工艺，再通过2,2-二苯基-1-苦基肼基(2,2-diphenyl-1-picrylhydrazyl, DPPH)、2,2′-联氮-双(3-乙基苯并噻唑啉-6-磺酸)二铵盐[diammonium 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonate), ABTS⁺]自由基清除率进行多糖抗氧化活性评价。最佳低共熔溶剂为氯化胆碱-乳酸(摩尔比1:2)，最佳超声温度50 ℃，最佳提取工艺为：料液比1:38、超声时间48 min、含水量42%，在此条件下多糖得率为(19.88±0.93)%。体外抗氧化活性实验结果表明，低共熔溶剂提取得到的天麻多糖对DPPH自由基和ABTS⁺自由基清除率分别最高可达(26.39±1.47)%和(30.61±0.16)%，这表明采用该低共熔溶剂提取得到的天麻多糖具有一定抗氧化能力，可作为潜在的天然抗氧化成分进行深入研究和开发。

Abstract:

This study optimizes the extraction process and explores the antioxidant activity of Gastrodia elata polysaccharides, aiming to provide theoretical reference for the extraction, development, and application of the polysaccharides. Polysaccharides were extracted from G. elata by an ultrasonic-assisted method with deep eutectic solvents. The extraction process was optimized by single factor and response surface tests. The antioxidant activity of polysaccharides was evaluated by DPPH and ABTS⁺ free radical scavenging rates. The optimal deep eutectic solvents were composed of choline chloride and lactic acid at a molar ratio of 1:2. The optimal extraction conditions were the ultrasonic treatment at 50 ℃ for 48 min, a solid-to-liquid ratio of 1:38, and a water content of 42%. Under these conditions, the polysaccharide yield reached (19.88±0.93)%. The results of antioxidant activity experiment in vitro showed that the scavenging rates of G. elata polysaccharides on DPPH and ABTS⁺ free radicals were up to (26.39±1.47)% and (30.61±0.16)%, respectively, which indicated that the polysaccharides extracted by the deep eutectic solvents had a certain antioxidant ability. The extracted polysaccharides can be further studied and developed as a potential natural antioxidant.