桑葚多糖超声提取、脱色工艺优化及其抗氧化活性分析

本文研究桑葚多糖超声提取工艺、树脂脱色工艺和体外抗氧化活性。以桑葚粗多糖得率为指标，通过单因素实验、正交试验考察超声提取温度、料液比、超声时间、超声功率的影响；以脱色率为指标，通过单因素实验、正交试验考察脱色时间、多糖溶液浓度、脱色温度的影响；通过ABTS法、DPPH法、邻二氮菲法、邻苯三酚法考察其抗氧化能力。结果表明，超声提取桑葚多糖的最佳工艺为:超声温度50 ℃、料液比1:30 g/mL、超声时间70 min、超声功率500 W，该条件下多糖得率为4.59%±0.25%；AB-8大孔吸附树脂脱色的最佳工艺为:脱色时间5 h、桑葚粗多糖溶液浓度4 mg/mL、脱色温度25 ℃，该条件下脱色率为62.34%±1.27%；桑葚多糖清除ABTS+自由基、DPPH自由基、羟基自由基和超氧阴离子自由基的IC₅₀分别为0.14、0.68、0.19和3.14 mg/mL。

Optimization of Ultrasound-Assisted Extraction and Decolorization Process of Polysaccharides from Mori fructus and Its Antioxidant Activity

The ultrasound-assisted extraction, resin decolorization process and antioxidant activity of polysaccharides from Mori fructus (MFPs) were investigated in this work. The effects of ultrasonic extraction temperature, solid-liquid ratio, ultrasonic time and ultrasonic power on extraction yield of MFPs were investigated by single factor and orthogonal test. Taking decolorization rate as index, the effects of decolorization time, concentration of polysaccharide solution and decolorization temperature were investigated by single factor and orthogonal test. ABTS assay, DPPH assay, phenanthroline method and pyrogallol autoxidation reaction were used to evaluate the antioxidant activity in vitro. The results showed that the optimal ultrasonic extraction conditions were ultrasonic temperature 50 ℃, solid-liquid ratio 1:30 g/mL, ultrasonic time 70 min and ultrasonic power 500 W. Under these conditions, the extraction yield of MFPs was 4.59%±0.25%. The optimal decolorization conditions were decolorization time 5 h, concentration of MFPs solution 4 mg/mL and decolorization temperature 25 ℃. Under these conditions, the decolorization rate was 62.34%±1.27%. MFPs had strong scavenging ability on ABTS+ radical, DPPH radical, hydroxyl radical and superoxide anion radical with half inhibitory concentration (IC₅₀) of 0.14, 0.68, 0.19 and 3.14 mg/mL, respectively.