A Paradigm Shift in Drying of Food Materials via Free-Volume Concepts

Abstract

We give an overview of the prediction of thermodynamics of food materials, and the kinetics of water transport in them using universal theories based on free volume concepts. These material properties are highly relevant to the prediction of food drying. These presented theories are shown to hold for a large class of polysaccharides and proteins. These different food materials apparently follow the soft matter paradigm that materials’ behavior at length scales larger than the molecular scale are dominantly determined by physical characteristics rather than their chemical details. We pose that for food and other bio-materials hydrogen-bonding is largely determining their physical behavior, as in drying.

[Supplementary materials are available for this article. Go to the publisher's online edition of Drying Technology for the following free supplemental resource(s): Data sets.]

Keywords:

• Free volume theory
• Moisture diffusion
• Sorption isotherm
• Universality