Temperature-dependent solubility of Rebaudioside A in methanol/ethanol and ethyl acetate mixtures:Experimental measurements and thermodynamic modeling  

作　　者：Zhenguang Liu Zexiang Ding Yifeng Cao Baojian Liu Qiwei Yang Zhiguo Zhang Qilong Ren Zongbi Bao 

机构地区：[1]Key Laboratory of Biomass Chemical Engineering of Ministry of Education,College of Chemical and Biological Engineering,Zhejiang University,Hangzhou 310058,China [2]Institute of Zhejiang University-Quzhou,Quzhou 324000,China

出　　处：《Chinese Journal of Chemical Engineering》2024年第8期164-176,共13页中国化学工程学报（英文版）

基　　金：supported by the National Key Research and Development Program of China(2021YFC2103800);the National Natural Science Foundation of China(U21A20301);the Research Funds of Institute of Zhejiang University-Quzhou(IZQ2022RCZX004 and IZQ2021RCZX015)。

摘　　要：The equilibrium solubility of Rebaudioside A(Reb A)FormⅡin binary mixtures of methanol/ethanol and ethyl acetate was quantitatively determined within the temperature range of 283.15—328.15 K at ambient pressure.The experimental findings indicate a positive correlation between the solubility of Reb A(FormⅡ)and both the temperature and the methanol/ethanol content in the solvent system.To describe the solubility data,six distinct models were employed:the modified Apelblat equation,theλh model,the combined nearly ideal binary solvent/Redlich—Kister(CNIBS/R—K)model,the van't HoffJouyban-Acree(VJA)model,the Apelblat-Jouyban-Acree(AJA)model,and the non-random two-liquid(NRTL)model.The combined nearly ideal binary solvent/Redlich—Kister model exhibited the most precise fit for solubility in methanol+ethyl acetate mixtures,reflected by an average relative deviation(ARD)of 0.0011 and a root mean square deviation(RMSD)of 12×10^(-7).Conversely,for ethanol+ethyl acetate mixtures,the modified Apelblat equation provided a superior correlation(ARD=0.0014,RMSD=4×10^(-7)).Furthermore,thermodynamic parameters associated with the dissolution of Reb A(FormⅡ),including enthalpy,entropy,and the Gibbs energy change,were inferred from the data.The findings underscore that the dissolution process is predominantly endothermic across the solvent systems examined.Notably,the entropy changes appear to have a significant influence on the Gibbs free energy associated with the dissolution of Reb A(FormⅡ),suggesting that entropic factors may play a pivotal role in the studied systems.

关 键 词：Rebaudioside A SOLUBILITY Thermodynamic modeling DISSOLUTION Binary solvent 

分 类 号：O642.1[理学—物理化学]