油茶籽壳多糖超声辅助提取工艺 优化及抗氧化活性分析

Abstract

旨在为开发利用油茶籽壳多糖提供基础，以油茶籽壳为原料，通过单因素试验结合响应面法对超声辅助提取多糖的工艺条件进行优化，并对超声辅助提取油茶籽壳多糖（CFP-U）的理化性质（分子质量、单糖组成、傅里叶变换红外光谱、紫外光谱、微观结构）和体外抗氧化活性（羟自由基、超氧阴离子自由基和ABTS+自由基清除率）进行了测定。结果表明：CFP-U的最优超声辅助提取工艺条件为超声时间20 min、超声功率650 W、液料比40∶ 1，在此条件下油茶籽壳多糖的得率为（3.28±0.06）%；高效凝胶渗透色谱分析表明，CFP-U的纯度较高，分子质量为91.6 kDa；高效液相色谱分析表明，CFP-U的单糖由平均摩尔比为0.05∶ 0.14∶ 0.05∶ 1.00∶ 0.05∶ 0.30∶ 0.35∶ 041的甘露糖、鼠李糖、葡萄糖醛酸、半乳糖醛酸、葡萄糖、半乳糖、木糖和岩藻糖构成；红外光谱表明，CFP-U存在α-糖苷键、β-糖苷键和吡喃糖环；紫外全波长扫描表明，CFP-U中基本不含蛋白质；扫描电子显微镜观察发现,CFP-U呈不规则形态，为片状结构，表面光滑；体外抗氧化活性测定表明CFP-U能有效清除羟自由基、超氧阴离子自由基和ABTS+自由基，并在一定浓度范围内呈剂量效应关系，且抗氧化活性优于传统热水法提取的油茶籽壳多糖。综上,采用超声辅助法可以有效提取油茶籽壳多糖，且油茶籽壳多糖具有较强的体外抗氧化能力。In order to provide a basis for the development and utilization of oil-tea camellia seed hull polysaccharides, using oil-tea camellia seed hull as raw material, the process conditions of ultrasonic-assisted extraction of oil-tea camellia seed hull polysaccharides (CFP-U)were optimized through single factor test and response surface methodology. The physical and chemical properties (molecular weight, monosaccharide composition, Fourier transform infrared spectroscopy, ultraviolet spectroscopy, microstructure) and in vitro antioxidant activity (scavenging rates of hydroxyl radical, superoxide anion radical and ABTS+ radical) of CFP-U were determined. The results showed that the optimal ultrasonic-assisted extraction conditions of CFP-U were ultrasonic time 20 min, ultrasonic power 650 W and liquid-solid ratio 40∶ 1, and the yield of CFP-U reached (3.28±0.06)% under these conditions. High performance gel permeation chromatography analysis showed that the purity of CFP-U was high, and its molecular weight was 91.6 kDa. High performance liquid chromatography analysis showed that the CFP-U was composed of mannose, rhamnose, glucuronic acid, galacturonic acid, glucose, galactose, xylose and fucose in an average molar ratio of 005∶ 0.14∶ 005∶ 1.00∶ 005∶ 0.30∶ 0.35∶ 0.41. The infrared spectroscopy showed that there were α-glucoside bond, β-glucoside bond and pyranose ring in CFP-U. Full-wavelength ultraviolet scanning showed that CFP-U contained almost no protein. CFP-U was observed by scanning electron microscope with irregular shape, smooth surface and sheet structure. The determination of antioxidant activity in vitro showed that CFP-U could effectively scavenge hydroxyl radical, superoxide anion radical and ABTS+ radical in a dose-response relationship within a certain concentration range, and the antioxidant activity of CFP-U was higher than the polysaccharides extracted by traditional hot water method. In conclusion, the ultrasonic-assisted extraction method can effectively obtain polysaccharides from oil-tea camellia seed hull, and the polysaccharides extracted has high antioxidant capacity in vitro.

Keywords

• 油茶籽壳；多糖；响应面法；超声辅助提取；抗氧化活性
• oil-tea camellia seed hull; polysaccharides; response surface methodology; ultrasonic-assisted extraction; antioxidant activity