芦荟多糖的制备工艺及稳定性研究

Research in technology of preparation and the stability in polysaccharide of aloe

目的 比较不同方法处理芦荟鲜叶外皮所制备的芦荟凝胶中芦荟多糖的含量,并考察其稳定性,为芦荟多糖的制备工艺提供依据.方法 以鲜榨汁法制备芦荟凝胶,醇沉法以60%、70%、80%、90%比例提取芦荟多糖,蒽酮-浓硫酸比色法测定不同醇沉比例所提取的芦荟多糖含量;比较不同方法处理芦荟鲜叶外皮所制备的芦荟凝胶中芦荟多糖的含量;考察芦荟多糖在不同温度、pH和氧化还原剂等条件下的稳定性.结果 以80%醇沉比例提取的芦荟多糖含量最高.芦荟鲜叶不去皮处理提取的多糖含量较去皮处理者高,为灰绿、灰褐或灰白色粉末;去皮处理者芦荟多糖含量较低,为偏白色均匀细腻粉末.芦荟多糖在低温、还原剂及pH值为5～7的溶液中稳定性较好,在高温、氧化剂及强酸、强碱溶液中稳定性相对较差.结论 以不去皮处理的80%醇沉组分芦荟多糖含量最高且粉末性状最佳,注意避免在高温下与氧化剂、强酸强碱溶液等一起使用.

Objective To compare the contents in polysaccharide of aloe in gel of aloe with preparation in different processing methods on fresh aloe of outer cuticle and investigate their stability. It could provide technology of preparation of polysaccharide of aloe.Methods The aloe gel had been prepared through the fresh juicing method, and alcohol sinking was applied to abstract polysaccharides of aloe in proportion of sixty, seventy, eighty and ninety percent. The colorimetric method of anthracenone - thick sulfuric acid had been taken to determine contents of polysaccharide in different proportions by alcohol sinking. The contents of polysaccharide were compared among different processing methods in fresh aloe of outer cuticle, and then the stability on condition of different temperatures, pH and the reagent of reductant-oxidant with polysaccharides of aloe were investigated. Results The content abstracted from polysaccharide of aloe was the higher when the proportion was eighty percent and its character of powder was better. And content abstracted from polysaccharide of aloe with the outer cuticle was higher than that out of the outer cuticle. The powders from the polysaccharide of aloe with the outer cuticle were gray-green, gray-brown or gray-white. The powders from polysaccharide of aloe without the outer cuticle were partial-white, more well-distributed and delicate. The stability in polysaccharide of aloe was better with the condition of low temperature, reducing agent and the solution with pH from five to seven, while the stability was lower when in high temperature, oxidizing agent and the solution with strong acid and strong alkali. Conclusions The proportion of eighty percent with alcohol sinking, decorticating the outer cuticle of fresh aloe has the higher content and the better character in the polysaccharide of aloe.