采用碱提醇沉法制备猴头菇β-葡聚糖(Hericium erinaceus alkali-extracted polysaccharide, HEAEP),系统研究了不同条件(抗坏血酸浓度、金属离子、温度、pH值等)下抗坏血酸对HEAEP表观黏度的影响,并深入分析了抗坏血酸对HEAEP结构特征的影响。研究结果表明:猴头菇β-葡聚糖表观黏度与抗坏血酸浓度存在依赖性,当抗坏血酸质量分数超过0.10000％时,抗坏血酸浓度越高,降解效果越差；金属离子(Cu2+、Fe2+)的加入会进一步促进抗坏血酸对HEAEP表观黏度的降解作用；而温度的影响相对较小；pH值和作用时间也有一定影响,当pH值为4,作用时间为12h时,抗坏血酸对HEAEP降解效果最好。此外,抗坏血酸能降低HEAEP分子质量,但对HEAEP糖苷键类型及比例、单糖组成和特征官能团等结构特征影响较小。抗坏血酸降低猴头菇β-葡聚糖表观黏度的效果受到多重因素的影响,其中抗坏血酸浓度、Cu2+、Fe2+等影响较大,但作用前后的多糖主要结构特征变化相对较小。研究结果旨在为抗坏血酸与β-葡聚糖共存食品的生产提供理论参考。
The Hericium erinaceus alkali-extracted polysaccharide (HEAEP, a kind of β-glucan) was prepared by alkali extraction and alcohol precipitation. The effect of ascorbic acid on the apparent viscosity of HEAEP under different conditions (ascorbic acid concentration, metal ion, temperature, pH value, etc.) was systematically studied, and the effect on the structural characteristics of HEAEP was analyzed. The results showed that the apparent viscosity of HEAEP was dependent on the concentration of ascorbic acid. When the mass fraction of ascorbic acid exceeded 0.10000%, the degradation effect was significant less with the increasing concentration of ascorbic acid. Besides, metal ions (Cu2+ and Fe2+) addition would further promote the reduction of apparent viscosity of HEAEP induced by ascorbic acid. Moreover, the relative less effect of temperature was observed. The influence of temperature is relatively small. In addition, the pH value and reaction time also had certain influence. When the pH value was 4 and the reaction time was 12 hours, ascorbic acid had the best degradation effect on HEAEP. Furthermore, ascorbic acid could reduce the molecular weight of HEAEP, but had little effect on the structure and characteristics of HEAEP such as glycosidic bond type and ratio, monosaccharide composition and characteristic functional groups. The reducing effect of ascorbic acid on the apparent viscosity of HEAEP was affected by multiple factors, among that the concentration of ascorbic acid and metal ions (Cu2+ and Fe2+) had a greater impact. However, the main structural characteristics of the polysaccharide did not change significantly before and after ascorbic acid treatment. The research results aimed to provide a theoretical basis for the production of coexisting foods of ascorbic acid and β-glucan.