Particle Size Analysis in Food
Published Online: 15 SEP 2006
Copyright © 2000 John Wiley & Sons, Ltd. All rights reserved.
Encyclopedia of Analytical Chemistry
How to Cite
Robins, M. M. 2006. Particle Size Analysis in Food. Encyclopedia of Analytical Chemistry. .
- Published Online: 15 SEP 2006
Techniques are described for determining particle size in food dispersions involving food particles ranging in size from 0.1 to 1000 µm, where the presence of the particles confers special properties such as texture, appearance or flavor release. Those foods of plant origin that are cellular in nature are outside the scope of this article, as their structure is not under the control of the food manufacturer. The techniques described are used to a greater or lesser extent on foods, and they are all methods in use in other industrial sectors. The techniques are classified according to their underlying physical principle. Summary tables are provided to act as quick reference guides for a potential user of the technique. After the detailed descriptions, the final section groups those techniques relevant to a specific type of dispersion.
The two most direct methods, microscopy and sieving, are discussed initially followed by three classes of optical technique, comparatively simple forward or back scattering, angular-dependent light scattering and dynamic light scattering. The next technique to be addressed is the electrical sensing zone originally developed by Coulter. Sedimentation techniques follow: gravitational sedimentation, centrifugal sedimentation and field-flow fractionation (FFF). All depend on the behavior of the particles in a force field that is balanced by viscous drag forces. The next two techniques are both acoustic in operation, either direct ultrasonic attenuation or electroacoustics. Finally, the novel applications based on nuclear magnetic resonance (NMR) are presented.