Colloidal aspects of ice cream—A review

Glass Transitions and Crystallization in Milk Powders

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

Publisher Summary This chapter focuses on “food polymer science” approach and illustrates various recent examples of the way it has been used to define structure–function relationships in food products and processes and to assess and understand the effects of glass transitions and water plasticization on food quality, safety, and stability. The chapter reviews some theoretical principles from the field of synthetic polymer science that have been shown to be applicable to the studies of the glassy state phenomenon in foods and illustrates those applications by means of a broad overview focusing primarily on the most recent experimental studies by a number of groups that have been especially active in this rapidly growing field of research. The results of such studies have demonstrated the major opportunity offered by the food polymer science approach to expand not only the quantitative knowledge but also, of broader practical value in the context of industrial applications, the qualitative understanding of food products and processes with respect to (1) structure–functional property and water relationships and (2) the influences of nonequilibrium glassy and rubbery states on time-dependent mechanical and rheological properties related to quality and storage stability.

Glass transitions and water-food structure interactions

Amorphous, noncrystalline solids are typical of low water content and frozen foods. Solids in these foods, e.g., confectionary, dehydrated foods, cereal foods, and frozen foods, often form nonequilibrium glass-like structures. The glassy state of the solids forms during food processing in a reversible glass transition. Vitrification can occur in numerous glassy states that exhibit various relaxations around the glass transition. The success of freeze drying, spray drying, and extrusion and the stability of dehydrated foods against flow, collapse, and crystallization is based on the control of the glassy state during the dehydration process and storage. Encapsulation processes often use glass-forming materials to entrap dispersed components or improve retention of volatiles. Plasticization of the noncrystalline structures by temperature or water reduce relaxation times exponentially above the glass transition, which results in rapid deterioration. Critical values for water activity and water content expres...

Glass transition temperature and its relevance in food processing.

https://stuff.mit.edu/afs/athena/course/other/kitchen-chem/www/research_papers/stability.commercial.ice.cream.pdf

T. J. Maurice

Papers

The Influence of Polysaccharides on the Glass Transition in Frozen Sucrose Solutions and Ice Cream

The use of thermal mechanical analysis to determine the influence of carbohydrates on stability of frozen dairy products.