痂状炭角菌发酵豆渣产多糖的结构、抗氧化和流变特性

文章通过症状炭角菌固体发酵豆渣制备多糖,利用高效液相色谱法(high performance liquid chromatography, HPLC)测定多糖的单糖组成及其比例,利用紫外可见近红外分光光度计、傅里叶变换红外光谱(Fourier transform infrared, FTIR)和扫描电子显微镜(scanning electron microscope, SEM)表征多糖结构,并对发酵底物多糖的抗氧化和流变特性进行研究。结果表明,发酵底物多糖主要是由葡萄糖醛酸(63.63%)、半乳糖醛酸(1.65%)、葡萄糖(11.88%)、阿拉伯糖(1.45%)、岩藻糖(18.85%)构成的杂多糖;紫外光谱分析表明该多糖不含蛋白质和核酸;FTIR分析表明该多糖是具有糖醛酸的酸性多糖;SEM结果表明,该发酵底物多糖表面呈表面光滑的多网孔状结构;流变结果显示该多糖溶液是典型的非牛顿流体;在质量浓度为0~8 mg/mL时,抗氧化活性结果表明,该多糖具有清除ABTS、DPPH和羟基自由基的能力。

The polysaccharide was prepared and purified from okara by solid fermentation of Xylaria escharoidea. The monosaccharide composition and proportion of the polysaccharide were determined by high performance liquid chromatography (HPLC). The structure of the polysaccharide was characterized by ultraviolet-visible-near infrared spectrophotometry, Fourier transform infrared (FTIR) spectroscopy and scanning electron microscope (SEM). The antioxidant and rheological properties of the polysaccharide of the fermentation substrate were studied. The results showed that the polysaccharide of the fermentation substrate was heteropolysaccharide composed mainly of glucuronic acid (63.63%), galacturonic acid (1.65%), glucose (11.88%), arabinose (1.45%) and fucose (18.85%). The UV spectrum showed that the polysaccharide did not contain protein and nucleic acid. The FTIR spectrum indicated that the polysaccharide was an acid polysaccharide with uronic acid. The SEM results showed that the polysaccharide surface of the fermentation substrate had a smooth multi-mesh structure. The rheological results showed that the polysaccharide solution was a typical non-Newtonian fluid. In the concentration range of 0-8 mg/mL, the results of antioxidant activity indicated that the polysaccharide had the ability to scavenge ABTS, DPPH and hydroxyl radicals.