Machining of wood of soft deciduous trees is currently based on the knowledge about cutting of wood of hard deciduous and coniferous trees and has not developed a comprehensive research methodology of cutting processes. Therefore, the objective of the study is a development of methodology for longitudinal sawing with circular saw and straight milling that would be utilized with a purpose of acquiring further knowledge on wood cutting and the improvement of cutting tool designs. Sub-objective of the study is determination of duration of cutter’s wear periods when using developed methodology. For the purpose of solving problems regarding cutting process of soft deciduous wood, the optimization of cutting tools and cutting modes were carried out in conditions that comply with the tendencies of the practise. The cutting process was carried out by a computer numerical control machine and the data acquisition by electronic measuring instruments. Aspen (Populus tremula L.) wood was used for wood samples. The methodology was developed for sawing, which complements the authors previously described methodology of the milling process investigations. Initially, only the results of periods of cutter wear and cutting velocity effects on these periods when milling process is used were obtained. It was concluded that the methodology can be used for further investigations and the critical wear period begins two times later when cutting velocity increases twice.

The purpose of the current research was to investigate the total protein content and amino acid composition of flour blend made from several types of whole grain flour for pasta production. Conventional rye, hull-less barley, triticale and wheat grain was used in the experiments. For the flour blend obtaining white wheat flour type 550 was used. Using standard methods the following quality parameters were analysed: protein content in grain and flour samples by using InfratecTM model 1241 Grain Analyzer, in flour blend – by AACC 46–20, amino acid content by LVS ISO 13903:2005. In the present research it was determined that it is possible to increase the total protein content in wheat flour type 550 by 11% if adding whole wheat or whole triticale flour, and by 7% if adding whole grain flour of hull-less barley. Higher total amino acid content was obtained for whole wheat flour sample; lower – for whole rye flour sample. Significantly lower total amino acid content was obtained in whole rye, hull-less barley and triticale flour comparing with whole grain wheat flour. No significant differences (p=0.779) were found in the analysed essential amino acid content made of different flour blend – the content of essential amino acids in the analysed flour blend samples was very similar.

Due to currently aggravating problems of global warming, more and more alternatives are being developed using a mixture of different fuels. The rapid development of science and engineering solutions can be the most efficient burning of the local biofuels to a minimum harmful substances from combustion process - including the CO2 emitted into the atmosphere. The research concerns fuel problem of choice between cost-effective, but environmentally harmful fuels. Research data will help further studies on the fuel in order to increase energy efficiency and rational use. The research was done in 2010, in Riga Technical University laboratories. An aspen wood and hard coal was used to create this fuel mixture. During the research, sampling, grinding, sifting and blending of different proportions, moisture and calorific value determination were carried out. It was determined that the calorific value of the mixture would increase linearly, exactly in the proportion of coal quantities added.

This work deals with the baking quality of the spelt wheat grain (Triticum spelta L.) compared with bread wheat (Triticum aestivum L.). Mixed flours were made of different share of spelt wheat and bread wheat (in total 11 mixtures) in 2016 in the Česke Budejovice in the laboratories of the Faculty of Agriculture. The technological quality of these mixtures was analysed, focusing on standard evaluation methods (protein content, characteristic of gluten or swellability of protein). The analysis was supplemented by complete rheological analysis made by Mixolab II. Bread was used as a model product. Subsequently, sensory evaluation of baked bread from the previously prepared mixtures was done. Part of the analysis was to estimate the economic basic bread recipe with different proportions of bread wheat and spelt wheat. The results were statistically analysed via STATISTICA 9.1 (StatSoft, Inc., USA). It was proved that the flour made of spelt can give cereal products with a higher nutritional value. The results have shown that the spelt grain is much more suitable for baking. Its advantage is the higher protein content and higher resistance of kneading of the dough and starch gelatinization rate, which was statistically confirmed. The main disadvantage is the higher price of spelt. According to the results, the ideal utilization of spelt wheat based on sensory analysis and economic calculations seems to be the mixture of spelt wheat and bread wheat, which results in an undeniable decrease of the product cost, and hence effects the common customer choice and taste preferences.

The composition of extracts isolated from black alder bark by ‘green’ microwave assisted water extraction in the temperature range of 70–150 °C was studied using the wet chemistry Folin-Ciocalteu method and Py-GC-MS/FID. The composition data were compared with those of the extracts obtained at the same temperature by accelerated solvent extraction (ASE) of bark. It was shown that microwave assisted extraction, compared with ASE, resulted in more significant transition of major cell wall components, including hemicelluloses and phenolics of lignin origination, into the solution. Depending on the microwave assisted extraction regimes, products with different portion of major cell wall components and secondary phenolic metabolites can be isolated that enlarge the possibilities of products valorisation. Thus, a significant promotion of secondary phenolic metabolites’ transition into extracts as a result of microwave extraction was observed at 70 °C. At that time the relative portion of carbohydrates in extracts was increased at high temperature extraction, combining dynamic and isothermal microwave heating. Water extraction of black alder bark in a microwave extractor revealed 25–50% lower specific energy consumption and 1.8–2.6 times higher productivity in comparison with the conventional extraction, that is beneficial in view of the upscale and practical application of this innovative biomass processing.

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 main direction of using wheat grains is grinding them into low-extraction flours. The flours collected from individual passages differ in terms of chemical composition and physical properties, which in turn differentiates their baking value. The aim of the study was to evaluate the baking value of passage flours obtained from the milling of spring and winter wheat grain. Wheat grain was milled in a 6-pass laboratory mill MLU-202 by Bühler. The baking value of the obtained passage flours was evaluated by an indirect method (protein content, gluten content and quality, falling number, farinograph analysis) and by a direct method (by baking and performing quality evaluation of the obtained bread). The research showed that the efficiency of flours from individual milling passages varied. The passages flours differed significantly in terms of chemical composition and baking value. The highest flour yields were obtained from the first and second grinding stages, while the smallest from the third grinding stage. Ash and total protein content, flour water absorption, and amylolytic enzymes activity increased together with the subsequent milling stage in both reduction-passage and grinding-passage. The gluten content increased with the next reduction stage, while it decreased with the subsequent grinding passage. The bread from the laboratory baking test was diversified in terms of sensory characteristics, loaf volume, and crumb porosity. The best quality bread was obtained from flour from the first two reduction passages. The lowest quality bread was obtained from flour from the final grinding passage.

Germinated grains are added to wheat dough with the purpose to promote the biological value of bread. As a result, a new product was obtained with a higher content of protein, fibre, B group vitamins; and vitamins C and E. The task was to investigate gluten quality changes at grain germination time, wheat dough rheological properties changes with various wheat, rye and barley amount additions, germinated for a different time. With the purpose to save maximum stability value of gluten, it was ascertained that the germination time of wheat grain could not be more than 24 hours. The best dough quality was obtained with germinated wheat grain additive. Germinated rye and barley grain additive (more than the experimentally ascertained amount) increases dough softening, decreases dough development time and dough stability. Only adding experimentally determined optimal amount of germinated grain, which promotes high quality bread, could produce dough with accepted rheological properties.