应用膜技术制备高纯度低聚果糖

研究了低聚果糖纳滤条件(操作压差、料液浓度、温度、循环流量、pH)对渗透通量和各糖组分截留率的影响,其最佳纳滤条件为:操作压差1.1MPa,料液浓度10%,温度40℃,循环流量为6L/min,pH6.0。应用纳滤提纯低聚果糖,其纯度达到85.05%。然而该纳滤膜对蔗糖具有较高的截留率,从而限制了低聚果糖纯度的提高空间。为了进一步提高低聚果糖纯度,研究尝试了将膜分离和酶反应耦联的技术,利用其边反应边分离的特性,滤除单糖,转化普通级低聚果糖中的蔗糖,最终获得高纯度低聚果糖,其纯度达到95.79%。

Preparation of high-purity fruocto-oligosaccharides by membrane technique

The effect of filtration pressure, feed concentration, temperature, circulation flow rate and pH on the permeation flux and the retention rate of each sugar were studied, and the optimum conditions for nanofiltration were filtration pressure of 1.1MPa,feed concentration of 10% ,temperature of 40℃,circulation flow rate of 6L/min,and pH6.0.The purity of FOS was increased to 85.05% from 53.49% by nanofiltration.However,the retention rate of surcose about the nanofiltration membrane was very high, and the purity of FOS could not increase any more. In order to obtain high-purity fructo-oligosaccharides, monosaccharides and sucrose were filtered or transformed by the combinations of membrane separation and enzyme reaction.And the net content of FOS was raised to 95.79%.