Molecular dynamics and structure in physical properties and stability of food systems

Physical properties and stability are critical for delivering safe and healthy food to the consumers and thus is a theme that attracts food scientists for a long time. Recently, literature suggests that stability can be fully grasped only if food molecular dynamics and structure are taken into consideration, i.e. an appropriate understanding of the behaviour of food products requires knowledge of its composition, structure and molecular dynamics, through the three-dimensional arrangement of the various structural elements and their interactions. Food systems behaviour is strongly dependent on the water molecular dynamics. Understanding changes in location and mobility of water represents a significant step in food stability knowledge, since water “availability” profoundly influences the chemical, physical and microbiological quality of foods. Nuclear magnetic resonance has been presented as a powerful technique to investigate water dynamics and physical structures of foods through analysis of nuclear magnetisation relaxation times, because it provides information on molecular dynamics of different components in dense complex systems. The application of this technique may be very useful in predicting food systems physicochemical changes, namely texture, viscosity or water migration. This paper aims at reviewing some of the main aspects related to food physical properties and stability, and the role of water in these properties. More specifically, this paper intends to contribute to a deeper understanding of the relationship of molecular constituents–structure–function of food systems, contributing to the development of foods with improved functionality.