Influence of the Specific Load on the Kinetics of the Process of Convective-Thermo-Radiation Drying of Apple Snacks

Abstract

Technology Blanching Drying Moisture content Vitamin C Energy consumption Snack Snacks are one of the varieties of the so-called "fast food" that is common in the modern world. There is a large number of snacks, both natural and with various additives. Based on the market analysis of snacks in Ukraine, there was a necessity to develop a new product that can be eaten by people with certain limitations and even children. The effectiveness of the drying process essentially depends on the specific loading of the raw material, which is determined by the mass (kg), referenced to unit area (m 2). The development of a new apple snack technology allows to get a product with low calorie content and a balanced chemical composition. In order to determine the optimal specific load of the semi-finished product, the study was carried out at a laboratory installation at different loads: 2.2 kg/m 2 , 4.4 kg/m 2 , 6.6 kg / m2, 8.8 kg/m 2 and 11.0 kg/m 2. As a result of research, five samples of snakes were obtained. The organoleptic and physical-chemical analysis of the obtained snacks showed that the optimal specific load on the dryer is 8.8 kg/m 2. The raw material for drying was the fall grade "Golden Delishes" apples. A particular advantage of these apples is the large fruit value (greater than 200 g), a greater ratio than other types of pulp to the seed chamber and a smaller peel thickness. This allows to minimize waste, which is essential, especially on an industrial scale. This variety of apples has high initial values, including the content of sugars and the sugar-acid index. The rational parameters of drying and intensification of the process are achieved by a combination of such drying parameters as shape and size of the material and its specific load. The combination of convective and thermo-radiation drying with impulse heat transfer to the apple snake surface allowed to achieve the desired qualitative technological characteristics and reduce energy costs compared to convective or thermos-radiation drying. The mechanism and intensity of the transfer of moisture in the material depend on the form of connection of moisture with the material, the diffusion of the vapor-gas medium through the capillary-pore structure of the material. The work presents the curves of drying and drying rates, the dependence of the heat and mass transfer coefficients under different loads by convective thermo-radiation power supply.