The utilization of traditional fossil fuels (oil, gas) as primary energy resources causes a destabilization of the eco-environmental situation in the world. Latvia has to significantly decrease energy imports from its neighbouring countries. This can be achieved by using high-quality local primary renewable energy sources. One of the solutions is to utilize anaerobic fermentation for biogas production. This process can be ensured by utilizing manure, food waste as well as energy biomass - wood, grass and maize. Biogas is utilized as a primary energy source in a cogeneration plant which is a combined cycle plant for electricity and heat power production. Microcogeneration plant for farming household needs would ensure an independent power supply, in case the overall electrical network is in a state of emergency. In order to ensure optimal biogas yield, which, in turn, would ensure a stable operation of the microcogeneration plant, it is important to know the parameters and quality of the biomass that have been filled in bioreactor. This research deals with the influence of the linkage biomass type on the qualitative and quantitative indicators of biogas. As a result, it has been found that biomass type affected the methane percentage in biogas greatly. The methane content of biogas independent with biomass type was diminished from 65% (galega) to 44.5% (fresh sawdust), but biogas yield decreased from 0.627 m**3 kgVSd E-1 (galega) to 0.185 m**3 kgVSd E-1 (fresh sawdust).

This paper presents results of pressure oscillation investigation in hydraulic hitch-system of a tractor Claas Ares ATX 557 during the motion during artificial roughness road test. During experiments oscillation at different driving speed, tyre pressure and hitch-system oscillation damping (turned on/off) were investigated. Tractor hydraulic hitch-system was equipped with a pressure sensor Wika Transmitter ECO-1 and data processing software PicoLog. Results of experiments present maximum pressure peak of 210 bar in the tractor hydraulic system when hydraulic hitch-system oscillation damping system at driving speed 8 km·hE-1 is not used and system pressure peak reduces to value of 180 bar if the hydraulic hitch-system oscillation damping is used.

Dairy ecosystems have been developing in thousands of years giving us wonderful collection of different types of cheese varieties. On the other hand, modern technology provokes the loss of variability (Adamberg et al., 2007). The only way to keep biological processes under control is to study physiology of microorganisms, and relationships between them systematically, especially non-starter lactic acid bacteria (NSLAB). The number of non-starter lactic acid bacteria increases during cheese ripening and may constitute a dominant population in the mature cheese. The NSLAB diversity, their metabolism and interactions with starter bacteria have an effect on the ripening process of the cheese. The aim of the present study was to investigate the diversity of Lactobacillus spp. during ripening of Krievijas cheese. The diversity of different profiles varied among the cheese samples matured at different temperatures, and the results indicated a correlation between NSLAB species and aroma development (Miķelsone et al., 2009). A higher metabolism of Lactobacillus curvatus at 12 deg C leads to faster depletion of nutrients and approaching the last two phases of microorganism growth curve. However, in each of the cheeses, the microflora had a tendency to be dominated by one Lactobacillus profile at the end of maturation.

Three spectrophotometric methods were compared for the assessment of milk fat oxidation: the AOCS (American Oil Chemists' Society) 2-thiobarbituric acid (TBA) value direct method, the TBA method of Aristova, and the modified method for the estimation of total carbonyl compounds in oils of Endo et al. Two cow milk fat samples – a fresh fat, obtained from fresh milk, and a rancid fat, obtained from a rancid commercial butter by means of high-speed centrifugation (15.871 × g, 30 minutes at 40 deg C) – were analyzed several times in a 22-day period after sample preparation. A positive linear correlation between absorbance and storage time was established in all used methods. The method of Aristova is appropriate for exact determination of oxidation products. This method had rather good R2 value (0.85) of the fresh fat sample results; however, the coefficient of variation (45.78%) showed rather large deviations between parallel analyses. The methods of AOCS and Endo et al. can be used for the assessment of the dynamics of fat oxidation by reporting absorbance values from the assay directly. By these methods rather high R2 values (0.86, 0.93) of the fresh fat sample results were obtained; the coefficients of variation also were satisfactory (10.13%, 11.12%). The last two methods are cheaper and require smaller sample amounts (less than 0.2 g), while the method of AOCS is the most time-consuming method.

Barley is a key ingredient in beer production. The aim of the current research was to study the dynamics of vitamin C and vitamin E in flaky and hull-less barley grains during steeping, germinating, and kilning. The research was accomplished on hull-less barley (two lines – '3528' and '3537') and flaky barley selected in Latvia in 2009 with a germination capacity above 95%. The grains were steeped, germinated and kilned using traditional malt production technology. During research the vitamin content was analysed using standard methods: vitamin C by EN 14130:2003, and vitamin E by AOAC 971.30. The content of vitamin C increased during steeping in flaky barley grains till 0.23 mg 100 gE-1, but in hull-less barley grains: line '3537' till 0.47 mg 100 gE-1, and line '3528' till 0.30 mg 100 gE-1. During germination vitamin C content in flaky barley increased by 68%, in hull-less barley: line '3528' – by 82%, and line '3537' – by 57%. The content of vitamin C in the analysed malt samples was 0.35-0.38 mg 100 gE-1. The content of vitamin E in all barley samples was similar after grain steeping. The content of vitamin E was 3.9 times higher in flaky barley, but in hull-less barley lines: '3528' – 4.1, and '3537' – 4.5 times higher compared with its initial content after germination. After grain kilning, the content of vitamin E decreased in all barley grain samples. The results show that using some cultivars of hull-less barley for malt production, it is possible to obtain a higher content of vitamins C and E in the end-product.

Nowadays one of most urgent problems is the production of healthy food which ensures normal maintenance of the human body. Rye bread is one of the bases of wholesome food. Every year scientists in Europe and other countries carry out investigations on the nutritional impact of processing rye. Interesting questions arise regarding changes in the biologically active compounds in rye bread as a result of processed. Connate antiradical activity (ARA) of rye bread affects free radicals by scavenging or donating electrons, which suggests that the ARA of rye bread averts attacks of free radicals on human cells. Therefore it is important to use antioxidants containing products with antiradical activity in human diets. The aim of this study was to analyse the impact of baking processing on rye bread antiradical activity. The object of the study was Latvian traditional rye bread baked in a commercial bakery, made with scald, and baked in a clay-floor firewood oven. The antiradical activity of rye bread crumb and crust was measured by using free radical 2.2-diphenyl-1-picrylhydrazyl (DPPH). It was concluded in the research that rye flour type 1740 has antiradical activity by scavenging 67 μmol·100gE-1 DM of the stable free radical DPPH, which is 13% more than the dough antiradical activity of the same flour. The antiradical activity of the crust is 49.6% more than the antiradical activity of the crumb. Baking time has no significant impact on changes in the antiradical activity of rye bread crumb.

The content of carbohydrates (fructose, glucose, and sucrose) and organic acids (citric acid, succinic acid, malic acid, sorbic acid, and ascorbic acid (vitamin C)) in organically grown vegetables (carrots, parsnips, celeriacs, and red beets) and dried vegetable products were analyzed by the HPLC reverse phase and ion exchange methods. The main carbohydrate detected in fresh vegetables invariably was sucrose (1.29 – 11.17 g 100 gE-1). Fructose and glucose were found in similar ranges (0.09 – 2.47 g 100 gE-1, 0.14 – 3.02 g 100 gE-1 respectively). A similar distribution of carbohydrates was determined in dried products. The highest fructose and glucose contents were found in fresh carrots - 2.47 g 100 gE-1 and 3.02 g 100 gE-1 respectively; but in dried carrot products – 14.53 g 100 gE-1 and 15.43 g 100 gE-1. High amounts of sucrose were found in red beets: 11.17 g 100 gE-1 in fresh samples, and 48.50 g 100 gE-1 in dried products. Malic and citric acids were detected as the main acids of fresh vegetables. Highest citric acid amount was in red beets (266.19 mg 100 gE-1), whereas celeriacs and parsnips had a high malic acid content. The results from this study demonstrated variability and concentration range of carbohydrates and organic acids, wherewith the organoleptic profile of the products. Dried products are considered as a good source of energy.

The major sugars in six cultivars grown in Latvia are analysed. The content of glucose, fructose and sucrose in strawberry, blackcurrant and redcurrant berries was determined by applying the method of high performance liquid chromatography (HPLC). By using the obtained calibration curves, concentrations of diverse sugars were found in the analyzed samples. Fructose or fruit-sugar, the same as glucose, is mainly the source of energy in the human body though it is decomposed faster and easier than glucose. In all the researched berry cultivars, the amount of fructose was the largest, particularly in blackcurrants. Six strawberry, black- and redcurrant cultivars were evaluated as raw materials for industrial production. The investigation involved chemical and sensory analyses of fresh berries. The results indicate that pH and sugars of fresh berries influence their quality. Furthermore, high level of sugar adversely affects taste stability. Taste degradation in berries is parallel to flavour deterioration. It is concluded that the main emphasis should be given to the properties of fresh berries.

The aim of this study was to evaluate physical and chemical changes in sous vide cooked marinated parent stock hen breast meat during refrigerated storage. Sous vide method is suitable for preparation of ready-to-eat meat products satisfying consumer demand for convenience and safety. Meat tenderness is recognized as important quality attribute of meats. The study involved preparation of the raw material, vacuum packaging of the products in polyamide/polyethylene (PA/PE) film pouches, marinating for 20 hours, sous vide cooking and chilling in ice water, followed by storage at 3.0±0.5 deg C. Each sample containing a chicken portion or chicken mix with shredded carrots, sea buckthorn sauce and spices was analysed during storage. Water activity, pH, and moisture were assessed during storage. Hardness (shear force) measurement was used as an instrumental method for meat tenderness evaluation. The differences between two studied products were noted regarding all studied parameters – water activity, pH, moisture content, and hardness. The differences mainly were determined by the properties of carrot and sea buckthorn additive, which generally have higher moisture content and lower pH. The researched parameters were well preserved during refrigerated storage for 28 days.

The aim of this paper is to evaluate all kinds of experiences with attractive EU funding for Latvia's private forest sector in the past and to generate new proposals for effective acquisition in near future. Latvian institution may learn from these experiences in order to improve their (acquisition) role in project proposals for the private forest sector. Consequently, the relatively underdeveloped Latvian private forest sector will get its highly needed support for better performance, and progress towards other, leading EU forest sectors. The possibilities for attractive financial EU support are reviewed through both historic experiences with the EU's 'Rural Development Program for 2007 – 2013' and the EU grants, designated for forestry projects. An extensive round of interviews is held with state forest owners and experts involved in forest management programmes and other dedicated EU forest funding initiatives. Following the expert interviews, two key indicators are developed to evaluate the support from the EU. Contacts with the EU countries (the Netherlands, Belgium, Finland and Poland) where similar forestry activities have been done as in Latvia were made. Research done in this work is unique as according to the author's information these countries do not have similar research related to the EU funds efficiency and Rural Development Program for 2007 – 2013. The successfulness of Latvian applications for the EU funding is one major indicator for further fund raising. The EU supported investments generally have higher economic results in comparison with their non EU funded counterparts.