摘要
文章基于电阻法分别对2%,5%甘露醇溶液及2%NaCl溶液(质量分数)的共晶点、共融点进行测量。结果表明:同种物料的共晶点温度低于共融点温度;相同溶质的溶液,其浓度越高,共晶点、共融点温度越低;不同溶质的溶液的共晶点、共融点温度不同。不同种类、浓度溶液的温度-电阻变化曲线不同,提出根据曲线特点采用不同的判定共晶点、共融点方法:有电阻突变值的采用突变点的温度,没有突变的曲线采用电阻变化率和电阻值结合的方法。
Based on the electric resistivity method,the eutectic and melting point of 2% 5% mannitol solution and 2% NaCl solution（mass fraction） were measured respectively.The results showed that： for the same kind of material,the eutectic point is lower than the co-melting was.The higher concentration of solution,the lower temperature of eutectic and co-melting was.Different solutes of solution have different eutectic and co-melting point.The curves of temperature-resistance will be different if the solutes and kinds of solution are different.According to the feature of measurement curves,proposed different methods to determine the eutectic and co-melting point： use temperature of mutation point as eutectic piont if the resistance mutated.Otherwise,combine the change rate and value of resistance to determine the eutectic and co-melting point.
出处
《食品与机械》
CSCD
北大核心
2012年第1期19-21,49,共4页
Food and Machinery
基金
国家自然科学基金青年基金项目(编号:50206013)
上海市重点学科建设项目(编号:S30503)
关键词
冷冻干燥
共晶点
共融点
电阻法
freeze-drying
eutectic point
co-melting point
electric resistivity method
