Platinum Metals Rev., 1990, 34, (1), 24
Meter for Food Samples
With the recent application of ohmic heating to food processing, during which an alternating current is passed through the food and sufficient heat is generated in situ to sterilise it, there has arisen a need to establish the electrical conductivity of food samples. For economic reasons, processing is usually carried out at 50 Hz, the frequency of the electricity power supply. However it is known that for foods with a high moisture content the electrical conductivity may be dependent on the frequency.
To support a study of the ohmic heating of foods being undertaken at the University of Cambridge, test equipment has been designed which enables the rapid measurement of the conductivity of food samples (F. R. G. Mitchell and A. A. P. de Alwis, J. Phys. E: Sci. In-strum., 1989, 22, (8), 554-556). The conductance meter cell and the associated electronic unit are described. Between experiments effective cleaning of the cell is essential, and it incorporates two 10 mm diameter platinised electrodes, between which the food is clamped.