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Effect of glass transitions on the rheological properties of food polymers
Author(s) -
Huang Victor T.
Publication year - 1999
Publication title -
macromolecular symposia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.257
H-Index - 76
eISSN - 1521-3900
pISSN - 1022-1360
DOI - 10.1002/masy.19991400114
Subject(s) - rheology , glass transition , materials science , crystallinity , polymer , viscosity , composite material , plasticizer , polymer science
The rheological properties of food products are highly dependent on the physical state of the structural matrix, which ranges from the glassy state, the glass‐rubber transition region, the rubbery plateau region, the rubbery flow region, and viscous flow region. Depending upon the combination of temperature and/or moisture content, the viscosity could be anywhere from 10 15 mPa.s for glassy material and 1 mPa.s for flowable, low viscosity liquid. During the glass transition range alone, the rheological properties can change as large as 1000 times. The rheological properties of ingredients, in‐process intermediates, and finished products also affect the processing techniques, textural quality, physical and chemical stability during storage. In this paper, the similarity in rheological behaviors between synthetic and food polymers, as affected by degree of crystallinity, cross‐linking, plasticization, and phase separation is reviewed. Various mathematical equations for modeling the changes in rheological properties during glass transitions are also discussed. The advantages and shortcomings of each model will also be compared.