1 A Practical Introduction to Differential Scanning Calorimetry. 2 Fast Scanning DSC. 3 ThermoGravimetric Analysis. 4 Principles and applications of mechanical thermal analysis. 5 Applications of thermal analysis in electrical cable manufacture. 6 Application to Thermoplastics and Rubbers. 7 Thermal Analysis of Biomaterials. 8 Pharmaceuticals. 9 Thermal methods in the study of foods and food ingredients. 10 Thermal analysis of inorganic compound glasses and glass-ceramics

Principles and applications of thermal analysis

The ice nucleation temperature determines the primary drying rate of lyophilization for samples frozen on a temperature-controlled shelf.

Most low water content or frozen food products are partly or fully amorphous This review will discuss the extent to which it is possible to understand and predict their behavior during processing and storage, on the basis of glass transition temperature values (Tg) and phenomena related to glass transition Two main conclusions are provisionally proposed Firstly, glass transition cannot be considered as an absolute threshold for molecular mobility Transport of water and other small molecules takes place even in the glassy state at a significant rate, resulting in effective exchange of water in multi-domains foods or sensitivity to oxidation of encapsulated materials Texture properties (crispness) also appear to be greatly affected by sub-Tg relaxations and aging below Tg Secondly, glass transition is only one among the various factors controlling the kinetics of evolution of products during storage and processing For processes such as collapse, caking, crystallization, and operations like drying, extrusion, flaking, Tg data and WLF kinetics have good predictive value as regards the effects of temperature and water content On the contrary, chemical/biochemical reactions are frequently observed at temperature below Tg, albeit at a reduced rate, and WLF kinetics may be obscured by other factors

Glass Transition and Food Technology: A Critical Appraisal

Annealing to optimize the primary drying rate, reduce freezing‐induced drying rate heterogeneity, and determine T'g in pharmaceutical lyophilization

Structure and ice recrystallization in frozen stabilized ice cream model systems

Recrystallization rates of ice in fructose solutions were determined over a range of temperatures and ice phase volumes. Accretive and migratory recrystallization both occur, the dominant mechanism being strongly dependent on the mean size of the crystals. Accretion dominated when crystals were small and close together. Recrystallization rates decreased with decreasing ice phase volume and decreasing temperature. The temperature dependence of the rates was consistent with Williams-Landell-Ferry kinetics. With a mean field correction for ice phase volume the observed data fit the recrystallization theory of Lifshitz, Slyozov and Wagner reasonably well.

Andy Sztehlo

Papers

Kinetics of Ice Recrystallization in Aqueous Fructose Solutions