低聚木糖溶液冷冻浓缩时冰晶生长动力学研究

Study on Growth Kinetics of Ice Crystal during Freeze Concentration of Xylo-oligosaccharides

研究了低聚木糖溶液冷冻浓缩时搅拌速度、冰晶种量和冷媒温度对冰晶生长动力学的影响。结果表明，随着晶核成熟时间的增加，冰晶生长速度下降，而且，生长时间1—3h，生长速度下降最快。搅拌速度越高、冷媒温度越低，冰晶生长速度越快，而且冰晶生长速度下降得越慢。冰晶种量越大，冰晶生长的初始速度越快；但冰晶种量过高，反而使冰晶生长的速度的降低加快。在低聚木糖初始质量浓度10．3g/L、初始溶液体积400mL、搅拌速度500r／min、冷媒温度为-1、5℃条件下，适宜的冰晶种量为10g。

The effects of stirring rate in the bulk solution, dosage of ice crystal seed and coolant temperature on the growth kinetics of ice crystal during freeze-concentration of xylo-oligosacchrides were investigated. It was showed that growth rate of ice crystal decreased with the ripening time of crystal nucleus. The growth rate was abated most prominently when ripening time of crystal nucleus was between 1-3 h, The higher the stirring rate or the colder the coolant, the faster the ice crystal grew. The greater the dosage of ice crystal seed, the greater the initial growth rate was, and the more rapidly the growth rate reduced. For freeze-concentration, the proper condition is： dosage of ice crystal seed 10 g at initial concentration of xylo-oligosaccharide 10.3 g/L, initial solution volume of 400 mL,stirring rate of 500 r/min and the coolant temperature of - 1.5 ℃