雪莲果皮多酚提取工艺及其抗氧化、抑菌活性的研究

以雪莲果皮为试验材料,以多酚提取率为指标,在单因素试验的基础上,采用正交试验法对超声辅助提取雪莲果皮多酚工艺参数进行优化,通过扫描电镜分析不同提取方式对雪莲果皮粉末表面微观形态的影响和提取得率的关系,同时评价雪莲果皮多酚的抗氧化活性及抑菌活性。结果表明最佳提取条件为:料液比1:35(g/mL)、提取温度65 ℃、乙醇体积分数40%、提取时间55 min。在此优化条件下,雪莲果皮多酚的提取率为193.87 mg/g;扫描电镜分析显示物料的破碎程度为:超声波提取法>加热回流法>浸提法>原材料粉末;抗氧化试验结果表明雪莲果皮多酚3 mg/mL浓度下对DPPH·清除能力为70.23%,IC₅₀值为0.71 mg/mL;对ABTS;·清除能力为97.96%,IC₅₀值为0.68 mg/mL;5 mg/mL浓度下总抗氧化能力为46.28 μmol Trolox/mL;抑菌试验结果表明雪莲果多酚对大肠杆菌和金黄色葡萄球菌均有一定的抑制作用,供试菌种的最小抑菌浓度(MIC)分别为2.5 mg/mL和0.625 mg/mL。以上研究结果表明,雪莲果皮多酚提取物可作为较好的天然抗氧化剂来源,具有开发为天然抑菌产品的潜力。

Extraction Optimization,Evaluation of Antioxidant and Antibacterial Activities of Polyphenols from Smallanthus Sonchifolius Peel

Taking Smallanthus sonchifolius peel as experimental material and polyphenol extraction rate as index,on the basis of single factor test,the process parameters of ultrasonic assisted extraction of polyphenols from Smallanthus sonchifolius peel were optimized by orthogonal test.The effects of different extraction methods on the surface micro morphology of Smallanthus sonchifolius peel powder and the relationship between extraction rate were analyzed by scanning electron microscope.At the same time,the antioxidant activity and antibacterial activity of Smallanthus sonchifolius peel polyphenols were evaluated.Results showed that the optimal extraction conditions were as follows:ratio of material to liquid 1:35 g/mL,extraction temperature 65 ℃,ethanol concentration 40%,and extraction time 55 min.Under the optimal conditions,the extraction ratio of polyphenols from Smallanthus sonchifolius peel was 193.87 mg/g.The canning electron microscopy analysis results showed that fragmentation degree of the material was as follows ultrasonic-assisted>heating reflux>organic solvent>raw material powder.Results of antioxidant tests showed that the IC₅₀values of polyphenols extracts against DPPH· and ABTS;· were 0.71 mg/mL and 0.68 mg/mL,respectively.Total antioxidant capacity of polyphenols extracts at 5 mg/mL was 46.28 μmol Trolox/mL.Results of antibacterial tests showed that the minimum inhibitory concentrations (MIC) of polyphenols extracts against Escherichia coli and Staphylococcus aureus were 2.5 mg/mL and 0.625 mg/mL,respectively.These results showed that the polyphenol from Smallanthus sonchifolius peel is a good source of natural antioxidants and antibacterial agents.