Abstract:
A state diagram shows the phases or states of foods as a function of solids or water content and temperature. The main advantage of drawing a map is to help understanding the complex changes when the solids content (or water content) and temperature of foods are varied. The recent state diagram is based on the glass transition line, freezing curve, maximal-freeze-concentration conditions, solubility line, eutectic point, solids-melting or solids-decomposition line, BET-monolayer line, and water-vapor line. Two fundamental concepts, water activity and glass transition are widely used to determine the stability of foods during processing and storage. Both concepts have their advantages and limitations when apply in different microbial, physical and chemical changes in foods. In the literature, it was emphasized that a combination of water activity and glass transition concepts could be a powerful tool in predicting food stability. Recently, water activity and glass transition concepts are combined in the state diagram by plotting BET monolayer as a function of temperature. It is now advanced with 13 micro-regions to determine different states or phases of foods. The current applications of the macro-region and micro-region concepts based on state diagram are discussed by presenting different chemical and physical changes during processing and storage. The issues of its applications in solving food-engineering problems are discussed considering examples, such as drying, baking, and chemical reactions. In really, foods are stable using hurdle technology (i.e. combined method). Finally, empirical approach to combine water activity, glass transition and state diagram are discussed.
Page(s):
143-143
DOI:
DOI not available
Published:
Journal: International Food & Nutrition Conference" August 18th-20th, 2022, University of Swat, Swat (Book of Abstracts), Volume: 1, Issue: 1, Year: 2022