Valutazione dell'uniformità di trattamenti a radiofrequenze

Radiofrequency processing has raised considerable interest in food industries where the main applications involve pasteurisation and sterilisation, roasting, blanching, post-baking drying, thawing and tempering. Since radiofrequency treatments allow the rapid heating of food by means of volumetric mechanisms, they are generally regarded as particularly uniform. However, few information is available on the actual uniformity of the electromagnetic field generated within the radiofrequency processing plants. To this aim, a methodology based on the image analysis of the extent of dehydration in silica gel plates containing cobalt chloride was developed Investigations on the uniformity of radiofrequency heating processes are reported. Model system trials were conducted using image analysis of the extent of drying of silica gel plates containing an aqueous solution of cobalt chloride. Results showed that this is a useful technique for monitoring uniformity of radiofrequency fields in processing equipment and for evaluating effect of process modifications.