Kinetics of convective drying during dehydration of poultry meat products

Abstract

Convective drying is a common method of dehydration of meat snacks (chips), which largely forms the competitive properties of the finished product. The kinetic parameters of drying (for example, the change in moisture and mass of the drying object during the process, the intensity and duration of drying) are the basis for the development and selection of equipment for the drying section of the industrial production of dehydrated meat products and process control. These indicators were determined experimentally, since they largely depend on the physical properties of a particular drying object, and it is not yet possible to calculate them with an accuracy sufficient for engineering practice. The kinetic parameters of convective drying of salted samples in the form of plates with a thickness of 2, 3, 4, 6, 8, 10 mm, made of chicken fillet meat blocks, have been determined. In order to ensure the adequacy of the research results to the conditions of industrial production, the main stages of the industrial technological process and the characteristics of the raw material samples were physically modeled: the composition of the curing mixture, the dimensions and physical properties of the raw material samples, and drying modes. The presence of complete volumetric evaporation during a period of constant drying rate of samples of raw materials with a thickness of 2, 3, 4 mm was revealed, as well as partial volumetric evaporation (about 90%) for samples with a thickness of 6, 8, 10 mm. A change in the physical mechanism of the drying process in the period of decreasing speed (cessation of volumetric evaporation and a multiple decrease in the intensity of evaporation) has been established. Dependences of the duration of the complete drying process (the sum of the periods of constant and decreasing speed) on the thickness of the raw material samples have been determined (for example, a 4 mm thick sample dries 25% slower than a 2 mm sample). Based on the research results, the possibility of increasing the productivity of the drying equipment (up to 60%) and optimizing the drying agent supply system to the drying object is shown.