Hurdle technology for dehydration of plant raw-material

One of the tasks of the food technologies today is to find ways of preserving products without losing such vital substances as vitamins and proteins. There are several methods of preserving: heating, freezing, salting, canning with certain acids, drying, radiation and etc. 'Hurdle' technology is based on several simultaneous methods suitable for good storage and stabilization of products. Nowadays we are researching how to use the electromagnetic energy of infra-red range of the wavelength (1,8-2,4mkm) penetrating the depth of 5-7mm and being absorbed by the water molecules in the vibration resonance mode in order to dehydrate plant raw-material. The experimental dryer was constructed, in which it was checked how such factors of the hurdle technology as low temperature of dehydration, high energy intensiveness, period of radiation and pulse mode affect the raw-material. Our tasks were to research how the degree of raw-material defragmentation, energy density and the period of infra-red radiation influence specific energy use for drying the bio rawmaterial and the count of microorganisms. Also the total time of the drying process, moisture, content of vitamins, aminoacids, macro- and microelements in raw-materials and food products were controlled. The object of research were dill and As a result of the research we discovered the modes of infra-red radiation ensuring harmless content of components and stability of dehydrated products. With the period of radiation 3,0-3,5 sec, the density of infra-red energy 12 kW/m2, and the length of dill 25-35 mm specific energy use was the lowest and amounted to 0,58 kWh/kg. Count of microorganisms was 102-105 colonies/g. With these parameters of drying the product preserve the nature quality of raw-material: 100% macro- and microelements, 85-90% aminoacids, 6570% vitamin C, 90-95% vitamin A, E, 80-90% B group vitamins. vegetables.