title: Simulation of the effect of hydrogen bonds on water activity of glucose and dextran using the Veytsman model.
abstract: Carbohydrates exhibit either van der Waals and ionic interactions or strong hydrogen bonding interactions. The prominence and large number of hydrogen bonds results in major contributions to phase behavior. A thermodynamic framework that accounts for hydrogen bonding interactions is therefore necessary. We have developed an extension of the thermodynamic model based on the Veytsman association theory to predict the contribution of hydrogen bonds to the behavior of glucose-water and dextran-water systems and we have calculated the free energy of mixing and its derivative leading to chemical potential and water activity. We compared our calculations with experimental data of water activity for glucose and dextran and found excellent agreement far superior to the Flory-Huggins theory. The validation of our calculations using experimental data demonstrated the validity of the Veytsman model in properly accounting for the hydrogen bonding interactions and successfully predicting water activity of glucose and dextran. Our calculations of the concentration of hydrogen bonds using the Veytsman model were instrumental in our ability to explain the difference between glucose and dextran and the role that hydrogen bonds play in contributing to these differences. The miscibility predictions showed that the Veytsman model is also able to correctly describe the phase behavior of glucose and dextran.
authors.affiliation: University of Illinois at Urbana-Champaign UIUC, College of Agricultural, Consumer and Environmental Sciences, Agriculture Engineering Sciences Building, 1304 West Pennsylvania Avenue, Urbana, IL 61801, United States. Electronic address: fdevito@illinois.edu.
authors.forename: Francesca
authors.initials: F
authors.lastname: De Vito
authors.affiliation: School of Systems Biology & Computational Materials Science Center, MS 6A2, George Mason University, Fairfax, VA 22030, United States. Electronic address: borisv@lk.net.
authors.forename: Boris
authors.initials: B
authors.lastname: Veytsman
authors.affiliation: Materials Science and Engineering Department, Penn State University, University Park, PA 16802, United States. Electronic address: painter@ems.psu.edu.
authors.forename: Paul
authors.initials: P
authors.lastname: Painter
authors.affiliation: University of Illinois at Urbana-Champaign, College of Agricultural, Consumer and Environmental Sciences, Department of Food Science and Human Nutrition, 103 Agriculture Bioprocess Laboratory, 1302 West Pennsylvania Avenue, Urbana, IL 61801, United States; Purdue University, Department of Food Science, 745 Agriculture Mall Drive, West Lafayette, IN 47907/2009, United States. Electronic address: kokini@illinois.edu.
authors.forename: Jozef L
authors.initials: JL
authors.lastname: Kokini
mesh_terms: D003198:Computer Simulation; D003911:Dextrans / Q000737:chemistry*; D005947:Glucose / Q000737:chemistry*; D006860:Hydrogen Bonding; D014867:Water / Q000737:chemistry*
chemical_list: D003911:Dextrans; D014867:Water; D005947:Glucose
keywords: Free energy of mixing; Glucose and dextran water activity; Hydrogen bonds; Miscibility of carbohydrates; Phase behavior of glucose and dextran; Veytsman association model