The rate of temperature increase in the inner layers of meat products during heat treatment in steam-air environments

Studies have been conducted to study the rate of temperature increase in the subcortical and central layers of meat products with a different ratio of moisture/fat content when heated in steam-air environments. Skinless chicken fillet (wet fat- free sample) was selected as the objects of research SBI, humidity - 74.5%, fat content - 1.4%) and the meat of the shoulder part of the pork carcass (low-moisture, greasy sample), humidity - 55.1%, fat content - 29.4%). The products were molded in the form of a one-dimensional cylinder and plate. Heating was carried out in an environment of dry air and a vapor-air mixture with a moisture content of 80-85% at coolant temperatures of 160 ... 240 °С. Measurements were carried out in the subcortical layer (upper moist) and in the center (inner moist). The general rates of temperature increase in the studied layers are determined, the observed patterns are described. For a more complete description, the process was divided into periods of heating and bringing to readiness; a variant of separation by heating rate was selected, which was carried out based on the results of an analysis of changes in excess temperature over time. To analyze the presented data, the ratios of the rates of temperature increase were calculated depending on the type of coolant and the sample. It is shown that the rate of temperature increase increases with an increase in the temperature of the coolant at both treatment periods for all the studied variants. At the initial stage, a higher rate of temperature increase is observed when heated in a vapor-air mixture (due to the predominant heat transfer due to condensation), at the main stage - in the air (due to the predominant heat transfer due to convection). For the subcortical layer, at the initial stage, a higher temperature increase is observed for the low-moisture, greasy sample, at the main stage - for the wet fat- free sample (due to the evaporative capacity of the material). For the center, a higher increase is observed for the wet fat- free sample in both periods (due to the inhibitory effect of the fat melt of the low-moisture, greasy sample).