State diagrams for improving processing and storage of foods, biological materials, and pharmaceuticals (IUPAC Technical Report)

Abstract

Supplemented temperature/composition phase diagrams include the non-equilibrium glass-transition temperature (T g ) curve and equilibrium ice-melting and solubility curves. The inclusion of the non-equilibrium curve allows one to establish relationships with the time coordinate and, thus, with the dynamic behavior of systems, provided that the thermal history of such systems is known.The objective of this report is to contribute to the potential applications of supplemented state diagrams for aqueous glass-formers, in order to describe the influence of water content, nature of vitrifying agents, and temperature on the physico-chemical properties of foods and biological and pharmaceutical products. These data are helpful to develop formulations, processing strategies, or storage procedures in order to optimize the stability of food ingredients and pharmaceutical formulations. Reported experimental data on phase and state transitions for several food and pharmaceutical systems were analyzed. Some methodological aspects and the effect of phase and state transitions on the main potential chemical reactions that can alter those systems during processing and/or storage are discussed.

Determination of glass transition temperatures during cooling and heating of low-moisture amorphous sugar mixtures

“…The temperature at which this transition occurs is well known as the glass transition temperature or simply Tg (Rhaman, 2010;Roos, 2010;Sablani et al, 2010). In recent years, the study of the relationship between Tg and water mass fraction (x w ) or solid mass fraction (x s ) has received considerable attention and is useful for construction of simplified stability/ mobility diagrams or supplemented state diagrams of several sugar-rich products, such as dried fruit and fruit juice powders (Rahman, 2006;Jaya and Das, 2009;Rhaman, 2010;Roos, 2010;Sablani et al, 2010;Buera et al, 2011).…”

Food Engineering at Multiple Scales: Case Studies, Challenges and the Future—A European Perspective

“…The process emphasizes the glass-forming characteristics of carbohydrates at low water contents and temperatures, while viscous flow required for structure formation can be achieved as a result of thermal and water plasticization above the glass transition of the solids [21]. The recognition of the underlying materials science principles was described successfully by state diagrams for dehydration, extrusion and freezing [4,5,23,24].…”

“…Theories of water activity as a mobility-controlling factor were complemented by information on the glass transition of particular food components at various levels of water plasticization [2,5]. The effects of the glass transition on oxidation, nonenzymatic browning reactions, enzymatic reactions, structural collapse and component crystallization have shown that glass transition affects and often explains the occurrence of such reactions although may not be sufficient as such to explain temperature dependence of deteriorative changes in foods [24].…”

State Diagram for a Waxy Rice Starch–Soluble Dietary Fiber Composite System

“…It assists in predicting the physical and chemical changes in foods during processing and storage. A growing number of studies have been conducted on different kinds of foods; however, these studies mainly focused on fruit, vegetables, and biomaterials . The state diagrams of rice, brown rice, potato starch, and extruded instant artificial rice have been reported.…”