The influence of solvent, storage time and temperature on the stability of the mycotoxin sterigmatocystin (STC) was investigated. STC calibrants (1.0 μg mlE-1) in acetonitrile, methanol and mixture of acetonitrile and methanol (50:50, volume/volume) were stored in dark glass bottles at (– 25), 4 and 25 °C for up to 8 weeks. Samples were analysed by high performance liquid chromatography (HPLC) with ultraviolet (UV) detection. Obtained results indicate that more suitable solvents for storage of STC standard solutions at (–25 °C) are acetonitrile and mixture of acetonitrile and methanol (50:50, v/v), but not longer than for one week; for storage at 4 °C more suitable is mix of acetonitrile and methanol, but not longer than for one week.

Renewable energy resources have been developing very fast due to negative effects and finite reserves of the fossil fuels. Biomass is ranked among the most promising renewable energy resources within the Central Europe. Corn (Zea mays L.) is currently the most widely grown crop in the Czech Republic; nevertheless, the cultivation of corn provokes soil erosion by water. Perennial energy grass called tall wheatgrass (Elymus elongatus subsp. Ponticus cv. Szarvasi-1) is supposed to be a good and environment-friendly alternative to corn. Field trials including these two crops were established in the experimental locality of South Bohemia. Their yield potential was monitored during spring harvest periods (use for combustion). Dry phytomass was fundamentally analysed (N, C, H, S) and higher heating value was determined too. Universal Soil Loss Equation was calculated for both crop species. Corn provided much higher average yield in a three-year interval; corn phytomass reached higher heating value as well. The area of Elymus elongatus should enlarge considerably, if we wanted to get the identical amount of energy from corn and Elymus elongatus. However, we found that, compared to Zea mays L., water erosion theoretical land losses would be several times less serious for Elymus elongatus.

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.

The objective of the current research was to investigate effects of germination on chemical composition of hull-less barley (Hordeum vulgare L. var. nudum Hook. f.), hull-less oat (Avena sativa), rye (Secale spp.), and wheat (Triticum spp.) grains for comparison. All the grains were cleaned, washed, steeped and germinated at temperature 35 ± 2 °C and relative humidity 95 ± 2% for 12, 24, 36, and 48 hours. After germination grains were dried till moisture content 14 ± 2%. Main quality parameters such as starch, proteins, b-glucan (in hull-less barley) and individual sugars were determined in cereals during their steeping and germination. Non-germinated grains were used as a control sample. In the present experiments non-significant protein content increase was observed in the analysed hull-less barley, hull-less oat, rye, and wheat during their germination for 48 hours. Starch content in hull-less barley, wheat and rye grains decreased non-significantly during germination for 24 h; opposite results were obtained for hull-less oat grains, where content of starch decreased by 16.7% after steeping and by 26.4% after germination for 24 h. b-glucan content in hull-less barley grains after germination for 48 h decreased by 20.5%. Non-significant changes were obtained in fructose content in analysed cereal grains during germination for 48 h; it was significantly increased after germination for 24 h and in germination for 48 h. Non-significant sucrose content changes were observed in hull-less barley, rye and wheat grains during germination for 12 h and in hull-less oat grains – for 24 h significantly increasing in future germination for 48 h.

The present study provides research in content of protein, starch, sugars and concentration of B group vitamins (thiamine, riboflavin, pyridoxine and niacin) in immature wheat (Triticum aestivum L.) compared to mature wheat kernels. The content of protein, starch was determined in kernels using Infratec1241 Grain Analyzer (Sweden), content of sugars was analysed by high- efficiency liquid chromatography HPLC (Shimadzu, Japan). The concentrations of vitamins were determined by high-efficiency liquid chromatography for vitamins B1, B2, B3, B6. Obtained results suggested that the immature wheat kernels obtained in milk stage showed higher contents of some compounds such as sugars and B group vitamins. The amount of all sugars presented in immature grains is higher and decreased uniformly during maturation. Therefore, immature grains are better sources of the B group vitamin that the mature grains, and therefore more nutritionally efficacious.