[关键词]
[摘要]
为探究酸性氧化电解水对植物总黄酮提取的预处理作用,选取槐米为实验材料并采用酸性氧化电解水预处理-乙醇回流两步法进行提取。将单因素实验结果作为依据,采取Box-Behnken法优化槐米总黄酮的提取工艺,并且通过测定清除DPPH自由基和羟基自由基的能力评价其体外抗氧化活性。结果证实,酸性氧化电解水预处理过程能明显提高总黄酮得率,这是因为酸性氧化电解水中含有一定量氧化态的氯。当有效氯含量由13.61 mg/L提高到322.22 mg/L时,其总黄酮得率由7.16%提高到20.88%。槐米总黄酮的最佳提取工艺为:酸性氧化电解水有效氯浓度250 mg/L,预处理时间160.53 min,乙醇体积分数60.89%,液料比36.60:1 mL/g。此工艺下的槐米总黄酮得率达到19.67%。体外抗氧化活性研究显示槐米总黄酮提取液对DPPH自由基和羟基自由基的最高清除率分别可达96.38%和92.30%,说明其具有较好的抗氧化活性,可作为一种天然的抗氧化剂。该研究成果首次将酸性氧化电解水运用于植物提取的预处理过程中,提出酸性氧化电解水预处理-乙醇回流两步法提取工艺,为得到更高的得率提供实验支撑和理论分析。
[Key word]
[Abstract]
In order to explore the pretreatment effect of acidic electrolyzed oxidizing water (AEOW) on the extraction of total flavonoids from plants, Sophora japonica was selected as experimental material and extracted by two-step method of AEOW pretreatment and ethanol reflux. Based on the results of single-factor experiment, the Box-Behnken method was used to optimize the extraction process of total flavonoids from Sophora japonica. The antioxidant activity in vitro was evaluated by measuring the ability of scavenging DPPH and hydroxyl free radicals. The results have confirmed that the pretreatment process of AEOW can obviously improve the yield of total flavonoids, because AEOW contains a certain amount of chlorine in oxidation state. When the available chlorine content (ACC) increased from 13.61 to 322.22 mg/L, the flavonoid yield increased from 7.16% to 20.88%. The optimum extraction process of total flavonoids from Sophora japonica was as follows: the ACC of AEOW was 250 mg/L, the pretreatment time was 160.53 min, the volume fraction of ethanol was 60.89%, and the ratio of liquid-to-solid was 36.60: 1 mL/g. The yield of total flavonoids from Sophora japonica was 19.67%. The antioxidant activities in vitro showed that the highest scavenging rates of total flavonoids from Sophora japonica on DPPH and hydroxyl free radical can reach 96.38% and 92.30%, respectively, indicating that it has good antioxidant activity and can be used as a natural antioxidant. In this research, AEOW was applied to the pretreatment of plant extraction for the first time, and a two-step extraction process of AEOW pretreatment and ethanol reflux was proposed, which provided experimental support and theoretical analysis for the extraction of total flavonoids from plants.
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[基金项目]
湖北省自然基金项目项目(2020CFB777);武汉轻工大学校立科研项目(2021Y21)