Safarov Jasur, Research Isothermal Medicinal Herbal, Republic of Uzbekistan, Tashkent state technical university- Tashkent. E-mail: email@example.com
Safarov Jasur et al. (2017), Research Isothermal Medicinal Herbal. Int J Nutr Sci & Food Tech. 3:1, 30-31. DOI: 10.25141/2471-7371-2017-1.0030
The paper studied the sorption and desorption of water vapor samples medicinal herbs Leonurus and mother-and-stepmother. Analysis
of sorption isotherms and desorption is important to clarify the characteristics of the forms of moisture due to the material. On the
basis of sorption isotherms of water vapor samples medicinal herbs Brunauer, Emmett and Taylor (BET) equation have been calculated
monolayer capacity, specific surface area, total pore volume and the radius of the capillary. Capillary-porous structure of the sample is
shown at 25 0C of dried medicinal herbs.
Drying, Capillary, Sorption, Desorption, Herbs
Capillary moisture is moisture free. It moves in the body as a liquid
(usually from the central body to the evaporation zone layers) and
a couple (through the evaporation zone by the dry layer outside). Nature formation of various types of moisture connection
mechanism causes its removal during drying. Thus, to remove
tightly bound water adsorption body must be converted into steam
inside the material and then moves it there in the form of steam.
For such a transformation required heat costs. Depending on the
mode of capillary drying process moisture moves in a fluid (due
to capillary forces) and form a pair (due to the difference of partial
The mechanism of sorption of low molecular weight substances
from medicinal herbs is complex and depends on many factors,
which include the phase and the physical condition of the herbs,
their porous structure, the chemical structure, the flexibility of the
chains, the intermolecular interaction and thermodynamic affinity
with sorbate (water).
According to the number of adsorbed water all substances during
the drying process herbs are divided into hydrophilic, hydrophobic
and moderately sorbing. Such a division is conditional, since the
sorption capacity herbs in the water depends on the temperature,
pressure and thermal history of the material.
The technique of water vapor sorption samples of medicinal
herbs is to establish the equilibrium concentration of the sorbedsubstance at a given partial pressure of vapor.
Vacuum measurement is made on the vacuum gauge VIT-1A
(ionization vacuum gauge, thermocouple) with a measuring range
from 10-1 - 10-3 Па. The working part consists of a cylindrical vessel, held in a vertical
position. Cylindrical receptacle consists of two parts which are
lapped each other using vacuum grease. To the top, inside, attached
quartz spring balance Mack Ben. On the quartz spring suspended
quartz or glass cup with the sample polymer. Stretching spring
quartz measured cathetometer KM-8[3-4].
Maximum moisture which may be due to sorption material vapor
from the environment (the maximum sorption capacity at φ=100%)
is called hygroscopic moisture content W. It can be defined on the
graph by the sorption isotherm isotherm crossing point with the
line φ=100%. The higher the moisture hygroscopic material, the
more it can absorb moisture from the air during storage.
Analysis of sorption isotherms and desorption is important to
clarify the characteristics of the forms of moisture due to the
material. Knowledge of hydrothermal equilibrium is necessary to
select the optimum mode of drying and storage of material.
Capillary-porous structure of the samples were dried medicinal
herbs with the desorption of water vapor, 25 0C is shown in table
On the basis of samples of water vapor sorption by the equation
of Brunauer, Emmett and Taylor have been calculated monolayer
capacity, specific surface area, total pore volume and capillary
- Ginzburg A.S., Fundamentals of the theory and technology of
drying foods. -M.: Food Industry.−527 p.
- Vullioud M., Marquez C.A., De Michelis A. Equilibrium sorption
isotherms and isosteric heat of rose hip fruits (rosa eglanteria). International Journal of Food Properties. 2006, 9 (4), p.823-833.
- Sazhin B.S. Fundamentals of drying equipment. -M., Chemistry. 320 p.
- Filonenko G.K., Grishin M.A., Goldenberg Y.M. et al. Drying edible vegetable materials. -M: Food Industry. -440 p.
- Norkulova K.T., Safarov J.E. Investigation of sorption and
desorption parameters hips. // Chemical Technology. Control and
management. -Tashkent, 2014. №5. С.9-12.