蚕沙低甲氧基果胶的提取工艺研究

采用酸萃取-铁盐沉淀法提取蚕沙低甲氧基果胶,通过单因素和正交实验确定最佳提取条件:用0.25%草酸水解,水解条件为:料液比1∶20（g/m L）、p H1.5、85℃、60 min,沉淀条件为:p H3.5、铁盐浓度0.5%。采用该优化工艺处理蚕沙,得到的果胶得率为5.21%。产品理化性质分析结果表明,该优化工艺提取的蚕沙果胶,其甲氧基含量5.62%,酯化度34.46%,半乳糖醛酸含量69.58%,品质达到国标要求。 

Study on extraction of low methoxyl pectin from silkworm excrement

Pectins were extracted from silkworm excrement by means of acid extraction and then molysite precipitation. A single-factor experiment and an orthogonal test were used to optimize the production conditions. The optimal conditions for pectin production were determined to include extraction at p H1.7 and a solid-liquid ratio of 1∶20(g/m L) in oxalic acid solution for 60 min at 85 ℃,and precipitation with 0.5% molysite solution at p H3.5. Under optimal conditions,the extraction rate of the pectin was 5.21%,the methoxy content and the degree of esterification(DE) was 5.62% and 34.46%,respectively,and the total galacturonic acid content of the pectin was 69.58%. Thus,the quality of the pectin was absolutely acceptable.