Glass Transitions in Foodstuffs and Biomaterials: Theory and Measurements

• Published in: Food Properties Handbook pp. 223 - 262
• Format: Book Chapter
• Language: English
• Published: United Kingdom CRC Press 2009; Taylor & Francis Group
• Subjects: Food & beverage technology; SCIENCE: GENERAL ISSUES; Glassy State; Master Curve; Viscoelastic Functions; Glass Transition Region; Dextrose Equivalent; FTIR Microspectroscopy; DMTA; Heat Capacity; BSE Scare; Fractional Free Volume; Storage Modulus; Glass Transition Temperature; Free Volume; Shift Factors; Constantan Disk; Tan Dmax; Enthalpic Relaxation; DMTA Measurement; Heating Rate; Glucose Syrup; WLF Equation; Local Segmental Motions; Conventional DSC; Moisture Content; Mathematical Expression
• ISBN: 9780849350054; 0849350050
• DOI: 10.1201/9781420003093-12

Acknowledgments... 239 References ... 239TRANSITIONIn the last century, rigorous scientific investigation facilitated the development of a clear concept regarding the crystalline solid state. This was based on the space lattice theory, in terms of atom groups arranged in regular periodic ordering, thus being unable to implement translatory motions relative to the molecular assembly (Sheppard and Houck, 1930). Similarly, an equally clear concept was obtained for the gaseous state, which according to the molecular kinetic theory, comprises an ensemble of particles in random translatory motion (Atkins, 1984). The nature of the liquid state has been the subject of less definite conceptions but, nonetheless, thermodynamic reasoning recognized the existence of sharp discontinuities separating the three states of matter (Haase, 1971). Kinetic considerations emphasize the unorganized movement of liquid molecules but modified by temperature-dependent interactions, leading to molecular groupings over a microscopic timescale of observation.