Organizing co mmittee

STUDY OF THE PROCESSES OF OBTAINING PECTIN 
FROM TWO PLANT SPECIES OF THE GENUS Crataegus 
 
M.S. Zokirova
1
, M.Kh. Malikova
2
, E.Kh. Botirov
2
 
 
1) Tashkent Institute of Chemical Technology, Tashkent, Uzbekistan,
е-mail: [e-mail] 
2) S.Yu. Yunusov Institute of the Chemistry of Plant Substance, Academy of Science of 
the Republic of Uzbekistan 
 
Crataegus 
is a genus of deciduous, rarely semi-evergreen tall shrubs or small trees 
belonging to the 
Rosaceae 
family, represented by more than 300 species, 10 of which 
grow in the mountainous and foothill regions of Uzbekistan. Representatives of the 
genus are widely used as an ornamental and medicinal plant, the fruits are eaten and are 
rich in pectin [1]. We have studied the fruits of 
C. songarica
and 
C. turkestanica
as a 
possible source of obtaining pectin substances. The output of pectin substances from the 
fruits of the above species is 9.6% and 11.2%, respectively. 
It has been established that the pectin substances of the two studied species of 
Crataégus
do not differ in their qualitative monosaccharide composition and, along with 
uronic acids, contain galactose, glucose, arabinose, xylose and rhamnose. There are 
differences in the quantitative content of these monosaccharides, however, uronic acids 
and arabinose are predominant. 
Solutions of pectin substances from hawthorn fruits with iodine solution give a 
characteristic blue color, which indicates the presence of starch-type glucans. 
The data of titrimetric analysis show that the pectins of the studied species of 
hawthorn are characterized by a high content of esterified carboxyl groups. Analysis of 
the IR spectra of pectin substances from the fruits of 
C. songarica
and 
C. turkestanica
shows that the studied biopolymers are carboxypolysaccharides with the main α–1→4 
glycosidic bond in the main chain. Determination of the relative viscosity (η
rel
) on an 
Oswald viscometer shows that the relative viscosity of pectin substances 
C. songarica
and 
C. turkestanica 
are η
rel
= 2.03 and 6.56, respectively. 
Determination of the molecular weights of samples of pectin substances by the 
method of universal calibration gel chromatography shows that the pectin isolated from 
C. songarica
consists of three components and its total molecular weight is 110,630 Da. 
Pectin isolated from 
C. turcistanica
consists of 2 components, with the molecular 
weight of the first component being 100,000 Da and the second component being 
10,000 Da. 
The fruits of the studied species of 
Crataégus
are rich in pectin substances and, 
according to their physicochemical parameters, they can be used in food production and 
medical industries.