There are different methods of egg yolk oil extraction, but still solvent extraction is commonly used. Due to the high cost of egg yolk powder production, extraction of lipids from liquid egg yolk remains very topical. Crude egg yolk oil obtained by solvent extraction from liquid egg yolk contains high amount of water which can decrease shelf life of egg oil promoting lipid oxidation. High concentration of residual solvents limits the usage of egg oil in food or in cosmetics due to the health risks. The aim of this study is to purify egg yolk oil obtained by solvent extraction from liquid egg yolk. Results show that it is possible to decrease the water content in egg oil from 14.26 ± 1.29% to 0.88 ± 0.13% by eliminating lecithin from egg oil. Solvent evaporation in the rotary film evaporator under the vacuum cannot remove solvents completely from the extract, but nitrogen streaming through the extract as a last step in evaporation process removes solvent residues, leaving behind high quality egg yolk oil suitable for food application.

Plantation willows are commonly grown plants which are widely used for energetic purposes that does not correspond completely to its potential. To fully integrate this resource into biorefinery scheme, it is necessary to study optimal conditions of willow bark processing, aimed for separation of bark components, their comprehensive characterization and profitable practical application. Extraction of secondary metabolites is well known approach for bark processing. But the separation of the main cell wall components including lignin from the residual biomass is less studied. In this work plantation residual willow bark after extractives separation by two different solvents (acetone and ethanolwater) was used as a feedstock for Organosolv delignification. Effect of temperature and catalyst used on the yield and properties of lignin isolated from residual bark by ethanol-water treatment was studied. It was possible to obtain pure lignin with high yields (up to 41%) that has the potential to be used for bio-plastic producing. Insoluble residue after delignification was carbohydrate rich (up to 80%) feedstock allowing its practical use for bioethanol producing.

Lactobionic acid is a high value added compound industrially produced through energy intensive chemical synthesis, which uses costly metal catalysts, like gold and platinum. In the next years, biotechnological production of lactobionic acid can be supposed to take the full transition to the manufacturing stage. Productivity of lactobionic acid by microbial production can be affected by various factors – choice of microorganism and its concentration, supply of oxygen, temperature, substrate, cultivation method, pH and aeration rate. The aim was to review research findings for lactobionic acid production as well innovative and efficient technology solutions for self-costs reducing. Whey was recommended as a cheap and suitable substrate for the lactobionic acid production. Whey processing has been advised with Pseudonomas teatrolens in 28 °C and in pH 6 to 7 for yielding the highest productivity. The increasing commercial importance urges the progression of schemes for lactobionic acid biotechnological manufacturing.

The paper analyses possibilities to model the concentration of DIN - a harmful pollutant from the eutrophication point of view-contained in the stream and self-purification processes of the stream. During the studies the data of a small right affluent of the river Musa (administrative district of Birzai) was used. The data comprised results of natural observations about the changes in DIN concentrations during the vegetation period and cold period of the year. The model of pollution dispersion through the stream is a parabolic differential equation with partial derivates, initial as well as boundary conditions. Constant DIN pollution in a stream stretch containing constant hydrological parameters and adequate environment conditions is proportional to the concentration of pollutants inflow. Further from the pollution source the constant pollution is exponentially decreasing. At the distance expressed by x (m) from the initial pollution concentration c0 measuring place, DIN concentration is expressed by C(x) = c0eE-0.00017x in the cold season of the year and by in C(x) = c0eE-0.00031x during the vegetation period. The stream polluted in the result of agricultural activity, further flowing through forest-covered area is significantly purified already at a 1.5 km stretch. Relatively, DIN concentration decreases about 3.8 times a day during the vegetation period and about 2.7 times a day during the cold season of the year.