【摘要】 试验旨在对海藻多糖的醇沉工艺进行优化并对其抗氧化活性进行研究。在料液比、加醇速度、搅拌速度、乙醇终浓度和醇沉次数单因素的试验基础上，以多糖含量为试验指标，利用正交试验法优化海藻多糖的醇沉工艺，以DPPH、OH、ABTS自由基的清除率对不同醇沉浓度下得到海藻多糖的抗氧化活性进行研究。结果表明：(1)最佳提取工艺为料液比1∶50 g/mL、搅拌速度200 r/min、醇沉浓度50%，加醇速度20 mL/min，醇沉3次，此条件下提取海藻多糖的含量为64.88%。(2)5种醇沉浓度海藻多糖化学组成存在差异，其总糖含量为46.21%～56.47%，糖醛酸含量为17.10%～21.82%，硫酸根含量为18.22%～24.17%，蛋白质含量为2.07%～3.14%。(3)抗氧化活性试验表明，乙醇浓度为80%醇沉多糖的抗氧化活性最好，对DPPH、OH、ABTS自由基综合指标的清除率最高，其半数清除率对应的浓度分别为3.82、0.91、1.23 mg/mL。综上所述，采用正交试验优化海藻多糖醇沉工艺的条件合理可靠，并且海藻多糖具有良好体外抗氧化活性。更多还原

【Abstract】 This study was to optimize the alcohol precipitation process of seaweed polysaccharide and study its antioxidant activity. Based on the single factor of solid-liquid ratio, the speed of adding, stirring speed, final ethanol concentration and the times of alcohol precipitation, the orthogonal test method was used to optimize the alcohol precipitation process of seaweed polysaccharides with polysaccharide content as the index. The antioxidant activity of seaweed polysaccharides obtained by different alcohol precipitation concentrations was studied by the scavenging rate of DPPH, OH and ABTS free radicals. The results showed as follows:(1) the optimal extraction process was as follows: liquid to material ratio was 1∶50 g/mL, the stirring speed was 200 r/min, the concentration of alcohol precipitation was 50%, the speed of adding alcohol was 20 mL/min, and the number of alcohol precipitation was 3 times, the content of seaweed polysaccharide was 64.88%.(2) There were differences in the chemical compositions of algal polysaccharides obtained under five ethanol precipitation concentrations. The total sugar content ranged from 46.21% to 56.47%, uronic acid content from 17.10% to 21.82%, sulfate content from 18.22% to 24.17%, and protein content from 2.07% to 3.14%.(3) The antioxidant activity experiment showed that the final concentration of 80% alcohol precipitated polysaccharide had the best antioxidant activity and the highest scavenging rate of DPPH, OH, ABTS free radical comprehensive indicators. The concentrations corresponding to the half clearance rates were 3.82, 0.91 and 1.23 mg/mL. It was proved by experiments that the conditions for optimizing the alcohol precipitation process of seaweed polysaccharides by orthogonal test are reasonable and reliable, and seaweed polysaccharides have good antioxidant activity in vitro.更多还原