Volume 29 (2013): Edition 1 (January 2013)

Horseradish is a perennial plant with significant antioxidant properties, and it contains about 0.2% to 1.0% of essential oil, mainly sinigrin, sinigrin-derived allylisothiocyanate and diallylsulphide. The aim of the study was to determine composition of volatile compounds of horseradish (A. rusticana L.) roots depending on the genotype. Volatiles from fresh horseradish roots of nine genotypes were extracted using solid phase microextraction with DVB/Car/PDMS fibre and were further analysed using gas chromatography-mass spectrometry. The volatile compounds were identified by comparing their mass spectra with mass spectral libraries (Nist98) and by calculating linear retention indexes and comparing them with the literature data. The studied horseradish genotypes differed both in the quantitative and qualitative content of aroma compounds. Totally 15 volatile compounds were detected, and their highest amount was found in genotype G12B. The main aroma compound of all horseradish samples was allylisothiocyanate, which formed 64-82% of the total identified volatile compounds. The obtained results were compared with those found in the literature. All horseradish samples contained significant amounts of phenylethylisothiocyanate (4-18%) that is formed from glucosinolate - gluconasturtin. The study revealed that genotype has great influence on the content of volatiles in horseradish roots.

Whole grain rye bread is a historically rich item in Latvian culture, and Latvians are rightly proud of the rye bread tradition they have cultivated. Much international research has shown that regular intake of rye bread positively influences the consumer health. Latvia has a long history of rye bread preparation, but lacks information about changes in vitamin content during the manufacturing process - from the beginning of baking till the end product - bread. The aim of the study was to investigate the changes in vitamin content during the whole grain rye bread production process. The object of the research work: traditional Latvian whole grain rye bread, the dough of which is prepared with scald and natural yeast and then baked in a wood-fired clay oven. AOAC standard methods were used to determine the content of thiamine (B1 vitamin), riboflavin (B2 vitamin), niacin (B3 vitamin), and α-tocopherol (E vitamin). The content of vitamins was analyzed in whole grain rye flour, leavened rye flour dough, and rye bread baked for 30, 45, 60 and 75 minutes. Bread crust and crumb were analyzed separately. The content of B complex vitamers in whole grain rye flour and bread was determined using LC-MS combined with stable isotope dilution assay. The study showed that whole grain rye bread contains a wide range of B complex vitamins. During the whole grain rye bread processing it was observed that, compared to vitamin content in flour, thiamine content reduced by 36%, but content of riboflavin, niacin and α-tocopherol increased by 53%, 40% and 6% respectively.

The objective of the research was to evaluate the quality of milk pomade sweet - sherbet - packaged in different packaging materials, using various packaging technologies. Four packaging materials were employed: two biodegradable films (Ceramis®-PLA coated with a barrier of pure silicon oxide [SiOx], and metallised NatureFlex 23NM), and two conventional films (metallised BOPET/PE, and Multibarrier 60 HFP as a control). Samples of sherbet were packaged using several technologies: active packaging (with incorporated ironbased oxygen scavenging sachets), modified atmosphere packaging consisting of 100% CO₂, and surrounding air ambience (control). The physicochemical properties - moisture, hardness, and colour - were analysed before packaging and after 2, 4, 6, 8, 10, 12, 14, and 16 storage weeks. The samples were stored at room temperature - +21±1 °C. At the beginning of the experiment, the quality of sherbet was excellent in terms of taste, smell, colour, moisture content, and hardness expressed by cutting force. During the storage, those properties changed and the quality of the product decreased. The research suggests this can be explained by the loss of moisture in some samples leading to hardening of the product, which in its turn directly influenced the colour stability expressed by total colour difference ΔE*.

A research on the NO_x reduction potential in diesel engine emissions injecting a 50% water-bioethanol blend in the engine intake system was carried out. Experiments were conducted on the test bench equipped with an Opel 16 DA four-cylinder 1.6-litre diesel engine and a two-tank system to run the engine on rapeseed oil. Toxic emissions were estimated using AVL SESAM FTIR multicomponent exhaust gas analytical system; the fuel consumption was measured using Kern 440-49A electronic weighing system. Three repetitions at the 1500 min^-1 and 2500 min^-1 engine crankshaft rotational speeds were performed; duration of each repetition - 120 seconds. Investigation results showed that such approach can reduce the nitrogen oxide content in exhaust gases by 32%, without significantly affecting other toxic emissions, at the same time reducing fuel consumption by 16-21%. Both rapeseed oil fuel and additive WE50 were derived from renewable resources, which plays an important role in elimination of climate changes.

The research contains theoretical analysis of the possibilities of development of a new type of devices for measurement of the consumption of energy resources in the communal services system. Novel alternatives for improvement of intelligent measuring instruments are offered in the article. On the basis of the presented calculation method, a mathematical model of the digital measuring signal for intelligent flowmeters at a uniform and at a non-uniform flow of liquids is offered. This would allow increasing the accuracy of the measuring signal as well as creating a new type of intelligent measuring devices for exact accounting of the consumption of energy resources in separate households of the communal services system. Theoretical researches showed that traditional flowmeters of cold and hot water in separate premises are unsuitable for commercial calculations as they make measurements in the critical zone of the error of the device, thus exceeding the admissible accuracy standard norm. Therefore the present state standards of Latvia for the water and heat energy account in households should be reconsidered. For assessment of the parameters of flowmeter’s target signal, a calculation method of the mathematical model with two keys of digital signals (basic and automatic correction) is offered. The main reasons of fundamental errors are defined. Examples how to calculate the target measuring signal are given. By using Laplace transform method, a novel mathematical calculation model of the measuring and correction signals of intellectual flowmeters has been developed.

Due to the development of knowledge society, there is increased demand for using knowledge management (KM) in an entrepreneurship as well as using information and communication technology (ICT). To achieve sustainable capacity it is necessary to promote KM and ICT in small, medium and microenterprises (SMME). KM is implemented successfully in the firms with large amount of employees. There are limited abilities to handle it for SMME. It is necessary to develop the model for implementation of KM for achieving sustainable capacity in SMME. The aim of this paper is to illustrate the model for strengthening sustainable capacity of SMME in transition to knowledge economy. Study of the bibliography was applied to define main dimensions of sustainable capacity of an enterprise. The active knowledge modelling method was applied to develop the model of KM solution for achieving sustainable capacity of SMME. As a result of research, a method for evaluation of sustainable development of SMME was developed. It reflects key elements for KM solution in SMME and consists of four interrelated sub-models such as goal model, business process model, concepts model, and information systems model. The model was evaluated in the target group as well as in the group of experts.

The author assesses the opportunities for inclusion of the corporate income tax into the budgets of the local governments on whose territories there are legally registered companies. For this purpose the same territorial code principle is recommended, which is applied to administer personal income tax. In order to motivate companies to register legally and engage in business activities in the regions of Latvia, tax incentives should be established. The application of tax incentives need to be delegated to the local governments, thus ensuring their interest in business development in their territories. The diversion of corporate income tax into the budgets of local governments would significantly strengthen their budget revenue base, increasing the interest of municipalities into the development and modernization of the companies, as well as creation of new jobs. Inherent risks are defined, and possible solutions how to eliminate these risks are suggested.

Based on the indicator of GDP per capita and the plan of business environment improvement measures, the urgency of developing lifelong learning in Latvia is analysed. Changes in the educational level of residents and in the education of employed individuals and job seekers in the period 2006-2010 are researched. The experts’ evaluation of the lifelong learning development alternative in Latvia was carried out using Analytic Hierarchy Process. The conclusions indicate that primarily the establishment of the lifelong education system in companies (priority assessment vector 0.322) should be developed.