Abstract

The external mechanisms that control drying rate are basically fixed by the operating conditions of the dryer being the temperature of the drying air the most important one. The final content of thermosensitive compounds is also determined by this condition and this is why the final quality of the product and the operating conditions are inter-related. The example of this phenomenon is the processing of pyrethrum. The organic compounds extracted from the Chrysanthemus cinerariaefolium flowers are called pyrethrins, which is the most ancient known natural insecticide. In this work, results obtained from the experimental drying of Chrysanthemus cinerariaefolium flowers are presented. Also, the influence of the drying air temperature on the pyrethrin content is established. The experimental data were used to derive a mathematical model that describes the drying rate and degradation kinetics. The external mechanisms that control drying rate are basically fixed by the operating conditions of the dryer being the temperature of the drying air the most important one. The final content of thermosensitive compounds is also determined by this condition and this is why the final quality of the product and the operating conditions are inter-related. The example of this phenomenon is the processing of pyrethrum. The organic compounds extracted from the Chrysanthemus cinerariaefolium flowers are called pyrethrins, which is the most ancient known natural insecticide. In this work, results obtained from the experimental drying of Chrysanthemus cinerariaefolium flowers are presented. Also, the influence of the drying air temperature on the pyrethrin content is established. The experimental data were used to derive a mathematical model that describes the drying rate and degradation kinetics.