Properties of Water in Foods in Relation to Quality and Stability

Session I. Fundamentals : high moisture systems.- Water and aqueous solutions : recent advances.- Phase separation in protein - water systems and the formation of structure.- The dipalmitoylphosphatidylcholine (DPPC) - water system.- An enzymatically modified protein as a new surfactant and its function to interact with water and oil in an emulsion system.- Session 2. Fundamentals : low and intermediate moisture systems.- The influence of soluble components on water sorption hysteresis.- Some facts concerning water vapour sorption hysteresis on potato starch.- Influence of temperature on sorption equilibria.- Development of B.E.T.-like models for sorption of water on foods, theory and relevance.- Solution thermodynamics and the starch-water system.- Session 3. Physico-chemical and enzymatic changes.- Effects of water activity and water content on mobility of food components, and their effects on phase transitions in food systems.- Enzyme activity as a function of water activity.- The influence of water content and temperature on the formation of Maillard reaction intermediates during the drying of plant products.- Polysaccharide-water interactions - thermal behavior of rice starch.- Session 4. Microbiology and water activity.- Present state of knowledge of aw effects on microorganisms.- Effects of aw and pH on growth and survival of Staphylococcus aureus.- Effect of aw on growth and survival of Bacillaceae.- Effect of water activity on mold growth and mycotoxin production.- The antimicrobial activity of sugar against pathogens of wounds and other infections of man.- Hurdle technology applied to meat products of the shelf stable product and intermediate moisture food types.- Session 5. Technology : diffusion properties and non equilibrium states.- Fundamentals of diffusion of water and rate of approach of equilibrium aw.- Diffusivity of sorbic acid in food gels at high and intermediate water activities.- Aroma diffusion : the influence of water activity and of molecular weight of the other solutes.- Choice of packages for foods with specific consideration of water activity.- The role of water in the rheology of hygroscopic food powders.- Session 6. Technology : humectants and new intermediate moisture foods (IMF).- A pragmatic approach to the development of new intermediate moisture foods.- Water binding of humectants.- Novel intermediate moisture meat products.- Extrusion cooking for cereal-based intermediate moisture products.- Polyglycerols and polyglycerol esters as potential water activity reducing agents. Chemistry and sensory analysis.- Session 7. Freezing and low temperature phenomena.- Complex aqueous systems at subzero temperatures.- The freezing of biological cells in aqueous solutions containing a polymeric cryo-protectant.- Freezing in polymer - water systems and properties of water.- Freeze-texturing and other aspects of the effects of freezing on food quality.- Computed instrumental analysis of the behavior of water in foods during freezing and thawing.- Session 8. Commodities : properties of water and technology.- Water in fish : its effects on quality and processing.- The effect of water on the quality of meat and meat products : problems and research needs.- Water in dairy products related to quality, with special reference to cheese.- Confectionery and water activity: determination of aw by calculation.- Session 9. Moisture measurement and prediction.- Comparison of sensors for measurement of air humidity.- Standardization of isotherm measurements (COST-project 90 and 90 bis).