Phenomenological Study of Enthalpy Relaxation and Physical Aging of Glucose, Fructose and Their Mixture

"Enthalpy relaxation of glucose, fructose and their mixtures was investigated using the Tool-Narayanaswamy-Monihan (TNM) and the Adam-Gibbs model parameters. The apparent activation energy was found to decrease as the fructose content increased. The value of parameter x increased with the fructose content, while parameter beta decreased as the fructose content increased to 50%. The parameter x was also evaluated using the peak-shift method and was found to be slightly higher than those obtained from curve fitting to the TNM and the Adam-Gibbs models in all sugars. The fragility of the sugars was also evaluated using the enthalpy relaxation data. The addition of fructose to the glucose-fructose system produced ""stronger"" liquids, but less non-linear behavior. The change in the parameters x and beta with the thermal history (i.e., aging time, aging temperature and cooling-heating rates indicated the failure of the original assumption of the models for the sugar systems."

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Agricultural Engineering

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2015

Author dc:creator

• Wungtanagorn, Ratchapong

Contributors dc:contributor

• Schmidt, Shelly J.

• Chemistry, Polymer

Language dc:language

eng

Identifier

(MiAaPQ)AAI9971226

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/86106