一种基于Flory-Huggins理论的等温吸附模型——用于分析小麦粉的水分吸附  

An Isothermal Sorption Model Based on the Flory-Huggins Theory:Application to Analyze Water Sorption of Wheat Flour

作　　者：李望铭 马荣琨[1] 贾庆超 徐娜 孔欣欣[1] 魏笑笑 LI Wangming;MA Rongkun;JIA Qingchao;XU Na;KONG Xinxin;WEI Xiaoxiao(College of Food Science and Engineering,Zhengzhou Institute of Science and Technology,Zhengzhou 450064,China;Food and Bioengineering Department,Zhengzhou University of Light Industry,Zhengzhou 450002,China)

机构地区：[1]郑州科技学院食品科学与工程学院,河南郑州450064 [2]郑州轻工业大学食品与生物工程学院,河南郑州450002

出　　处：《食品工业科技》2025年第1期114-120,共7页Science and Technology of Food Industry

基　　金：河南省教育厅高等学校重点研究项目支持(NO.22B550021)。

摘　　要：本文基于Flory-Huggins方程提出一种水分等温吸附模型,该模型采用Langmuir模型表示结合水的吸附,其余水分在干物质-结合水体系中的吸附遵循Flory-Huggins方程,并采用橡胶弹性理论的幻影模型计算弹性作用对水分化学势的贡献。采用动态水分吸附分析仪测定了小麦粉在20、30、40℃时的吸湿及解吸平衡水分,对所提出的模型进行分析验证。结果表明,采用本文提出的等温吸附模型能够很好描述小麦粉的水分等温吸附特性,预测的Flory-Huggins相互作用参数χ在0.86~1.52之间,大分子交联浓度在3000~6400 mol/m3之间,说明所提出的模型是合理的。基于该模型的分析显示,温度对平衡水分含量的影响主要归结为对Langmuir水含量的影响,在中低水分活度时混合效应是决定化学势的主要因素,而在高水分活度时弹性效应的贡献不容忽略。In this work,an isothermal sorption model was proposed based on the Flory-Huggins theory.In the framework of the proposed model,adsorption of the bound water was assumed to follow the Langmuir isotherm,and the adsorption of the rest water to the solid-bound water mixture was described using the Flory-Huggins adsorption theory.In addition,the contribution of elasticity effect to chemical potential of water was also included into the model and calculated based the phantom model of rubber elasticity theory.Water adsorption and desorption isotherms of wheat flour were determined using a dynamic vapor sorption system at 20,30 and 40℃,and adopted to validate the proposed model.The results showed that the proposed model could give a good prediction of isothermal water sorption in wheat flour,with the Flory-Huggins interaction parameterχranging from 0.86 to 1.52 and the cross-linking density of polymer ranging from 3000 to 6400 mol/m3,which suggested that the model was reasonable.Analyzing the water sorption of wheat flour based on the proposed model indicated that the impact of temperature on equilibrium water content could mainly attribute to its influence on the Langmuir water,in addition,mixing effect dominated the chemical potential of water at low-mediate water activities,while elasticity effect became nonnegligible at high water activity levels.

关 键 词：水分吸附 FLORY-HUGGINS 理论 LANGMUIR 吸附 橡胶弹性 化学势 小麦粉 

分 类 号：TS213.2[轻工技术与工程—粮食、油脂及植物蛋白工程]