Organizing co mmittee

CONTENT OF LIGNIN IN THE LICORICE ROOT RESIDUES 
B. B. Abduazimov, R.M. Khalilov 
S.Yu. Yunusov Institute of the Chemistry of Plant Substances Academy of sciences of the 
Republic of Uzbekistan st. Mirzo-Ulugbek, 77, 100170 Tashkent 
By estimates of the Regional Program for Sustainable Agricultural Development in 
Central Asia and Caucasus, over 70 per cent of licorice harvested and prepared in 
Uzbekistan exported abroad, including China, Germany, France and South Korea. 
Uzbekistan exported 2281.05 tons of licorice roots to China in 2010. According to the 
chamber of Commerce and industry of Uzbekistan, more than thirty enterprises and 
companies with different forms of ownership are engaged in harvesting and processing 
of licorice root in various regions of Uzbekistan. Natural reserves of licorice root are 
most actively due to climatic features growing in the south in the territory of 
Surkhandarya, Kashkadarya regions, north-west in the Republic of Karakalpakstan and 
the Khorezm region [1]. The significant part of the biomass is remains as a residue after 
the extraction of glycyrrhizin. According to the latest data, about more than thousand 
tons of licorice roots are processed inside Uzbekistan. 
The key component of interest for the employing of licorice is glycyrrhizin or 
glycyrrhizin acid. The extraction of glycyrrhizin is often performed using an aqua-
ethanol solution at high temperatures. Applications in traditional and herbal medicine 
are particularly related to the inhibitory effect to the action of 
Helicobacter pylori
, 
therefore working as a liver protector, due to flavonoids found in licorice root. 
The current work we examined lignin quantity of residues of licorice roots taken 
from the factories, processed by water and aqua-ethanol extraction at high temperature. 
Common quantification of lignin mainly relies of sulfuric acid hydrolysis known as 
Klason-lignin analysis [2]. This method is achieved in the industry and commonly in 
biomass refinery processes. 
Our study demonstrates that residues content 29.84±0.89 % lignin. and 5.09±0.21 % 
ash. This quantitative content of lignin in the residues is observed mainly in softwood. 
Reminding, lignin is the second most abundant natural polymer and the leading 
natural source of phenolic compounds. The value of lignin as naturally renewable 
source has significant potential in the field of biorefining to produce value-added such 
as aromatic organic products, carbon nanofibers, ameliorant, grow stimulator, fertilizers, 
fuel briquettes etc. In the following investigations we will study possible way of 
valorizations of lignin in its unmodified form or after modifications. In future, 
producing medicine from extracts and conversion of residues for agricultural protectors 
will increase the profitability of agricultural and phytochemical enterprises in the 
regions of Uzbekistan.