Water, the most abundant constituent of natural foods, is a ubiquitous plasticizer of most natural and fabricated food ingredients and products. Many of the new concepts and developments in modern food science and technology revolve around the role of water, and its manipulation, in food manufacturing, processing, and preservation. This article reviews the effects of water, as a near-universal solvent and plasticizer, on the behavior of polymeric (as well as oligomeric and monomeric) food materials and systems, with emphasis on the impact of water content (in terms of increasing system mobility and eventual water "availability") on food quality, safety, stability, and technological performance. This review describes a new perspective on moisture management, an old and established discipline now evolving to a theoretical basis of fundamental structure-property principles from the field of synthetic polymer science, including the innovative concepts of "water dynamics" and "glass dynamics". These integrated concepts focus on the non-equilibrium nature of all "real world" food products and processes, and stress the importance to successful moisture management of the maintenance of food systems in kinetically metastable, dynamically constrained glassy states rather than equilibrium thermodynamic phases. The understanding derived from this "food polymer science" approach to water relationships in foods has led to new insights and advances beyond the limited applicability of traditional concepts involving water activity. This article is neither a conventional nor comprehensive review of water activity, but rather a critical overview that presents and discusses current, usable information on moisture management theory, research, and practice applicable to food systems covering the broadest ranges of moisture content and processing/storage temperature conditions.

Beyond water activity: recent advances based on an alternative approach to the assessment of food quality and safety

Nano-engineering block copolymer aggregates for drug delivery

Poly(ionic liquid)s: An update

The field of enthalpy relaxation is reviewed. Current phenomenologies for dealing with the non-linear and non-exponential character of enthalpy relaxation are presented, and their successes and shortcomings are discussed. Qualitative experimental data and quantitative parameterizations are summarized, and some directions for future research are suggested.

Enthalpy relaxation and recovery in amorphous materials

Physical aging of polymers

Introduction. Step-Growth Polymerization. Free Radical Addition Polymerization. Ionic Polymerization. Copolymerization. Polymer Stereochemistry. Polymerization Reactions Initiated by Metal Catalysts and Transfer Reactions. Polymer Characterization-Chain Dimensions and Structures. The Crystalline State. The Amorphous State. Mechanical Properties. The Elastomeric State. Structure-Property Relations. Polymer Liquid Crystals. Polymers for the Electronics Industry. Index.

Polymers: Chemistry and Physics of Modern Materials

Diminution de l'excedeur d'enthalpie avec le temps de vieillissement, en accord avec le modele empirique a 3 parametres de Cowie et Ferguson, determination de la variation avec la temperature de ces 3 parametres. Comparaison des resultats avec le modele de temps de relaxation de Petrie et Marshall

Physical aging studies in poly(vinylmethyl ether). I. Enthalpy relaxation as a function of aging temperature

Alcohol-water cosolvent systems for poly(methyl methacrylate)

The effect of molecular weight and casting solvent on the miscibility of polystyrene-poly(α-methyl styrene) blends

Analyse des donnees en relation avec les modeles de Cowie-Ferguson et Petrie-Marshall et comparaison avec les donnees obtenues pour les homopolymeres; le PUME dans le melange vieilliT independamment du PS et est le principal responsable des effets du vieillissement, le PS Ralentissant le processus de vieillissement du PUME dans le melange

John M. G. Cowie

Papers

Polymers: Chemistry and Physics of Modern Materials

Physical aging studies in poly(vinylmethyl ether). I. Enthalpy relaxation as a function of aging temperature

Alcohol-water cosolvent systems for poly(methyl methacrylate)

The effect of molecular weight and casting solvent on the miscibility of polystyrene-poly(α-methyl styrene) blends

Physical aging studies in polymer blends. 2. Enthalpy relaxation as a function of aging temperature in a poly(vinyl methyl ether)/polystyrene blend