Перегляд за Автор "Petrova, Zhanna"

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Determination of rational modes of pumpkin seeds drying
(2018) Pazyuk, Vаdym; Petrova, Zhanna; Chepeliuk, Oleksandr
Pumpkin seeds are an easily accessible source of protein and other useful substances. A purpose is to determine a rational mode of its drying, which ensures high germinability of the seeds. The physical and mechanical properties of pumpkin seeds «Stofuntovyi» of Ukrainian selection with a humidity of 0, 6, 16, 46 % have been investigated. The drying process kinetics have been investigated on a test bench of convective drying at the following conditions: the drying agent temperature in the drying chamber t = 40–80˚C, velocity V = 1,5 m/s, the moisture content of dry air d = 10 g/kg d.a. The biochemical properties of dried pumpkin seeds were determined by the amount of seeds capable of forming normally developed sprouts under optimal conditions on the 5th, 7th and 10th days of germination. The studies of the properties of pumpkin seeds variety have revealed that when the initial moisture content in the material changes from 0 to 46%, there is an increase in the seeds’ geometric sizes: the length increases by 38%, width – by 10% and thickness – by 8%. Other parameters change too. Investigation of the pumpkin seeds drying process has shown that when the temperature of the drying agent increases, the drying intensity increases also. In particular, the drying time reduces 8 times when the drying agent temperature is raised from 40 to 80 °C. The drying rate curves corresponding to the falling drying rate period with preheating indicate that the highest drying rate at the maximum critical point at a drying agent temperature of 80 °C is 2.32% / min, and the lowest at 40 °C is 0.33 %/min. The heating of the pumpkin seeds takes 3 to 5 minutes depending on the mode, then the temperature of the material does not change significantly and deviates from the temperature of the drying agent by 0.1–0.5 ºС. The generalized curve of kinetics of pumpkin seeds drying makes it possible to describe the general process at different drying modes. The drying agent temperature substantially affects the pumpkin seeds germinability. The most rational mode of drying is at a temperature of 40 °C and an air speed of 1.5 m/s.
Effect of treatment modes on quality and antioxidant properties of tomato and beet processing products
(2018) Petrova, Zhanna; Pazyuk, Vаdym; Samoilenko, Kateryna; Chepeliuk, Olena
The research was conducted to substantiate the rational drying conditions of tomato seeds. The ratio and drying conditions of the composition from tomato waste with the addition of red beet were substantiated. The tomato seeds were prepared according to the traditional methodology used in the industry. From red beet and tomato waste compositions with the ratios of components 4:1, 3:1, 2:1, 1:1 were created. Tomato seeds have been dried using the convective method at the air temperature t = 50–80˚C, as well as the composition from red beets and pulp of tomatoes – at t = 60–100 ºС. The quality of dried seeds was estimated on the basis of its germinability, dried mixtures – on the content of betanin in them. When the temperature of the air increases, the intensity of tomato seeds drying increases too. Thus, the drying time reduces by 2.5 times when the air temperature is raised from 50 to 80 °C. However, qualitative seed material, which gives the germinability of 98%, has been attained at the drying temperature of 50 ºС. Non-waste processing of tomatoes involves the creation of compositions of pulp tomatoes and sliced red beets, their drying, grinding and packing. In industrial conditions, red beets need to be cut into chips, which intensifies the drying process of the composition. The slicing of tomatoes in compositions does not affect the process speed. When the air temperature increases from 60 to 100 °C, the intensity of compositions drying is raised by 1,8 times. Maximum preservation of the useful substances in the finished product results from the choice of a soft drying condition and an air temperature of 60°С. pH = 3.9 is characteristic for the ratio of red beet-tomato components 3:1 in composition, which ensures the maximum preservation of betanin (94.7%) at drying. The heat carrier temperature substantially affects the tomato seeds germinability and antioxidant properties of tomato and beet processing products.