以Hailwood-Horrobin平衡水分模型分析聚葡萄糖吸潮机理  

A Study on the Mechanism of Polydextrose Moisture Absorption Analyzed by Hailwood-Horrobin Equilibrium Moisture Model

作　　者：刘畅[1,2,3] 王梦雅 宋洪东 曹子怡 颉宇 李兴军 宁国庆 LIU Chang;WANG Meng-ya;Song Hong-dong;CAO Zi-yi;JIE Yu;LI Xing-jun;NING Guo-qing(College of Health Science and Engineering,University of Shanghai for Science and Technology,Shanghai 200093,China;Institute of Grain Storage and Logistics,Academy of National Food and Strategic Reserves Administration,Beijing 100037,China;National Engineering Research Center for Grain Storage and Logistics,Beijing 100037,China;Renliang Biotechnology(Shanghai)Co.LTD,Shanghai 201800,China)

机构地区：[1]上海理工大学健康科学与工程学院,上海200093 [2]国家粮食和物资储备局科学研究院粮食储运研究所,北京100037 [3]国家粮食储运工程研究中心,北京100037 [4]人良生物科技(上海)有限公司,上海201800

出　　处：《粮油食品科技》2024年第3期140-147,共8页Science and Technology of Cereals,Oils and Foods

基　　金：院所企业合作课题(H22076)。

摘　　要：为解释聚葡萄糖的吸潮性能,改进包装材料,在20~35℃和平衡相对湿度(ERH)10%~90%范围内,测定了初始含水率(IMC)1.01%~4.89%的5个国产样品(a1~a5)的水分吸附与解吸等温线。吸附和解吸等温线均是S型曲线,在ERH小于80%时,解吸等温线与吸附等温线之间存在滞后现象,样品初始含水率越低,滞后现象越显著。由于聚葡萄糖是无定形相态的粉末,我们假定聚葡萄糖水分吸附过程是蒸汽相态、液体相态(多分子层吸附)及固体溶液(单分子层吸附)之间存在的平衡,按照Hailwood-Horrobin(HH)模型把S型吸附等温线去卷积为单分子层(Mh)和多分子层成分(Md),吸附和解吸多分子层水含量随ERH增加呈现S型曲线增加,解吸单分子层含水率随ERH增加保持不变,而吸附单分子层含水率随ERH增加对a1~a4样品(IMC4.87%~2.35%)缓慢增加,对a5样品(IMC 1.01%)几乎线性减少。随着样品初始含水率降低,吸附位点聚合物分子量对a1样品最大,对a5样品最小。尽管红外光谱扫描显示a5样品羟基(3416cm^(–1))和无定形结构官能团(1027cm^(–1))的强度最小,但是a5样品的吸潮率最大。说明不同工艺加工的聚葡萄糖样品含水率越低,吸附单分子层水含量随ERH增加几乎线性减少,但是吸附多分子层含水量随ERH增加是S型增加,吸潮率和吸湿量增大。To explain the moisture adsorption properties and improve the package material of polydextrose product,the adsorption and desorption isotherms of five domestic samples with initial moisture content(IMC)of 1.01%~4.89%were determined in this study in the range of 20~35℃and ERH10%~90%using a dynamic water sorption analyzer.The adsorption and desorption isotherms were sigmoidal-shaped curves,and there was a hysteresis between desorption isotherm and the adsorption isotherm when ERH was less than 80%.Because polydextrose is an amorphous phase powder,we assumed that the water adsorption process of polydextrose was an equilibrium that existed among the vapor phase,the liquid phase(polylayer adsorption)and the solid solution(monolayer adsorption),and the adsorptive and desorptive sigmoidal-shaped isotherms can be de-convolved into a monolayer(Mh)and a polylayer component(Md)in accordance with Hailwood-Horrobin(HH)model.The polylayer water content of adsorption and desorption showed a sigmoidal increase with increasing ERH.The monolayer water content of desorption remained constant with increasing ERH,while that of the adsorption increased slowly for samples a1 to a4 with IMC 4.87%to 2.35%and decreased almost linearly for sample a5 with IMC 1.01%.As the IMCs of the samples decreased,the molecular weight of the polymer at the sorption site was maximum for sample a1 and minimum for sample a5.Although the FTIR showed the smallest intensity of hydroxyl group(3416 cm^(–1))and amorphous structural functional group(1027 cm^(–1))for a5 sample,a5 sample had the largest moisture absorption rate.These results suggested that,for the lower moisture content of polydextrose samples processed by different processes,their adsorptive monolayer water content seemed to decrease almost linearly with an increase of ERH.However their adsorptive polylayer water content sigmoidally increased with an increase of ERH,and their moisture absorption rate and hygroscopic capacity increased.

关 键 词：聚葡萄糖 水分吸着等温线 吸潮率 单分子层吸附 滞后环 

分 类 号：TS201.7[轻工技术与工程—食品科学] S-3[轻工技术与工程—食品科学与工程]