The article is devoted to the use of modern methods of the study of vegetable raw material for apple snacks production. To establish the optimal variety of apples there was used the analysis of technological parameters that depend on their chemical composition, especially on the quantity of dry substances, sugar-acid index and food fibers content. The study of inactivation degree of oxidative enzymes and possibility to prevent the protopectin hydrolysis process allowed establish the effectiveness of preliminary preparation of apples. The research-industrial drying setting, constructed by the authors, gave a possibility to study the different drying processes at the expanse of combination of convective and thermoradiative ways of energy supply and to establish the optimal regime of apple snacks drying. This elaboration allows receive product with high organoleptic indices, shorten the drying process and lower specific energy consumption.

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.

Introduction. The influence of differential heat treatment on products from apples with different sugar content in semi-finished products is considered. Materials and methods. Material for drying elect apples varieties «Golden Delicious». Samples of dried apples, snack and candied fruits were analyzed by organoleptic, physico-chemical and differential-thermal effects. The prepared semi-finished products were dried by the convective-thermoradiationаl method at a coolant temperature of 60 °C, a coolant movement speed of 5.5 m/s, a specific load of 8.8 kg/m 2 , an exposure value of thermal radiation heating elements of 8 kW/m 2 , and an external heating element power of 2.5 kW/m 2. The results and discussions. Based on the drying curves, the rate of moisture removal occurred in direct proportion to the increase in the concentration of sugar in the products. Drying time of products depends on the content of dry substances (DM) in semi-finished products: which were 12% for dried apples, 18.2% for snack and 72% for candied fruits. Energy costs for dried apples, snack and candied fruits are respectively 5.9; 7.55; 19.8 kW in kg of raw materials and 1.93; 1.99; 26.0 MJ/kg of evaporated moisture. The dependence is observed, the greater the concentration of sugar in the semi-finished product, the longer it takes to remove moisture from the material. In the presented derivatograms, when apples were heated in the T1 = 108 °C region, a mass loss of Δm = 13.0% was observed, which was accompanied by an endothermic peak on the DTA dependence. This mass loss is due to evaporation of moisture. When the temperature increased to T2 = 140 °C, destruction began to occur in the sample. When the snack was heated at T1 = 108 °C, the mass was lost by Δm = 14.5%, which was accompanied by an endothermic peak on the DTA dependence. As the temperature rises to T2 = 131 o С, destruction begins to occur in the sample. Heating the candied fruit at T1 = 109 °C resulted in a weight loss of Δm = 14.8% with an endothermic peak on the DTA dependence. As the temperature rises to T2 = 125 o C, destruction begins to occur in the sample. Conclusions. Based on the derivatogram (T, TG, DTG, and DTA time dependencies), the prediction factor (k0) was calculated for dried apples, snack and candied fruits to be 55; 61; 70 and also activation energy (E) for dried apples, snacks and candied fruits, respectively, 186; 203 and 236 kJ/mol.

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