龙须菜酶解制备琼胶寡糖的工艺优化

Process Optimization of Preparation of Agarose Oligosaccharides by Enzymatic Hydrolysis of Gracilaria lemaneiformis

通过酶解条件的优化来提高琼胶寡糖水解度,以得到低聚合度的新琼寡糖。试验研究了底物浓度、酶解温度、反应p H、加酶量、酶解时间和龙须菜颗粒大小对酶解过程中水解度的影响。酶解产物采用琼胶酶直接酶解龙须菜制备琼胶寡糖,简化琼胶寡糖制备工艺。结果表明,最佳酶解工艺为:底物浓度0.5%,酶解温度45℃, pH 6.5,琼胶酶加酶量10 U/mL,纤维素酶加酶量6.5 U/mL,龙须菜颗粒大小为过40~60目筛,酶解时间5 h,对应的水解度为56.6%,还原糖含量为4.652 mg/mL。通过液相色谱分析酶解产物主要为新琼四糖,存在少量新琼二糖,为功能性琼胶寡糖应用打下基础。

The enzymatic preparation of agaro-oligosaccharide from Gracilaria lemaneiformis by using agarose,which examined the influence of different factors on the enzymatic hydrolysis process.Agaro-oligosaccharide preparation process is simplified.The results showed that substrate concentration of 0.5%,hydrolysis temperature of 45℃,p H of 6.5,agarase enzyme dosage of 10 U/mL,cellulase enzyme dosage of 6.5 U/mL,Gracilaria lemaneiformis paticle size of 40-60 meshes,and hydrolysis time of 5 h were found to be optional for degrading of agar.The degree of hydrolysis of Gracilaria lemaneiformis was 56.6%.The content of reducing sugars was 4.652 mg/mL.The products were identified by HPLC,which mainly was Neoagarotetraose,there was also a small amount of neo-agarobiose,laying the foundation for the development and application of functional oligosaccharides agar.