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The efficiency of different wood coatings against water surface absorption
2021
Iejavs, J., Forest and Wood Products Research and Development Inst., Ltd., Jelgava (Latvia) | Ruluks, O., Forest and Wood Products Research and Development Inst., Ltd., Jelgava (Latvia) | Laiveniece, L., Forest and Wood Products Research and Development Inst., Ltd., Jelgava (Latvia) | Jakovlevs, V., Latvia Univ. of Life Sciences and Technologies, Jelgava (Latvia) | Pugovics, K., Latvia Univ. of Life Sciences and Technologies, Jelgava (Latvia) | Lise, S., Latvia Univ. of Life Sciences and Technologies, Jelgava (Latvia) | Spulle, U., Latvia Univ. of Life Sciences and Technologies, Jelgava (Latvia)
In the market of the Latvia different wood surface coating materials suitable for use in outdoor conditions are offered, but available information on the efficiency of these against direct water exposure is insufficient. For structural timber building elements, such as glued laminated timber (GLT), the surface coating should be applied taking into account technological, visual or colour changes (ISO 7724:1984) and – last, but not least – economic aspects are considered. Wood surfaces coated with coating materials, such as varnishes, paints, etc. can stabilize some properties such as movement of moisture content, dimensional changes and attack by microorganisms and fungi. The changes in the moisture content of timber may influence such important parameters as mechanical properties and the total life time of the structural timber elements. A study has been conducted with the aim of assessing the efficiency of coating materials used for wood protection against water absorption. In this study, six different commercial coating products used for the treatment of spruce (Picea Abies L. Karst.) and pine (Pinus Sylvestris L.) samples were tested. The efficiency of different coating substances was assessed using two modified test methods according to the standards EN 382-2 (1994) and EN 927-5 (2006), determining the surface water absorption after immersion in water for 24 h and the dynamics of water absorption of the glued laminated timber for 696 h kept in water. As a result of the study, it has been ascertained that organic solvent-based commercial coating products are more efficient against short-term and long-term wood water absorption compared to oil-based coating materials.
Показать больше [+] Меньше [-]State decoupling audit of low-carbon agricultural production
2021
Datsii, O., Interregional Academy of Personnel Management, Kiev (Ukraine) | Levchenko, N., National Univ. Zaporizhzhia Polytechnic (Ukraine) | Shyshkanova, G., National Univ. Zaporizhzhia Polytechnic (Ukraine) | Dmytrenko, R., Vinnytsia National Agrarian Univ. (Ukraine) | Abuselidze, G., Batumi Shota Rustaveli State Univ. (Georgia)
It is stated that the strategic benchmark for transformational changes in the economy is currently low-carbon production, the achievement of which is possible to provide with the consistent application of an arsenal of strict control measures, in particular, the introduction of state audit of low-carbon production. The effectiveness of the mechanism for ensuring the implementation of the UN Framework Convention on Climate Change has been assessed. The necessity of implementation in the domestic practice of the state audit of low-carbon production by the decoupling approach is proved. The agri-business portfolio has been formed according to the decoupling approach as one of the leaders in greenhouse gas pollution. The author's economic and mathematical models of estimation according to the decoupling approach of the impact of branches of crop and livestock production on environmental pollution are proposed. The dependence of greenhouse gas emissions on the volume of gross output of agricultural production, capital investment and current expenditures on environmental protection has been established. The results of a comparative analysis of the realism of forecasts of changes in greenhouse gas emissions according to the methodology of the National Academy of Sciences of Ukraine and the author's methodology are highlighted. A roadmap for the introduction of a state low-carbon decoupling audit of the state decoupling audit has been proposed as part of the preparation of the second nationally determined contribution to the Paris Agreement. The expediency of supplementing GRI 300 “Environmental Disclosures” with the group of indicators GRI-305.5 “Reduction of GHG emissions”, formed by the decoupling approach, is substantiated.
Показать больше [+] Меньше [-]The novel solution for acid whey permeate application in animal feeding
2020
Lakstina, J., Tukuma piens, SC, Tukums (Latvia) | Aboltina, I., Dairy laboratory, Ltd., Ulbroka, Stopiņi Municipality (Latvia) | Vanaga, L., Livestock Experimental Station “Jaunpils”, SC, Jaunpils, Jaunpils Parish (Latvia) | Jonkus, D., Latvia Univ. of Life Sciences and Technologies, Jelgava (Latvia) | Zagorska, J., Latvia Univ. of Life Sciences and Technologies, Jelgava (Latvia) | Cinkmanis, I., Latvia Univ. of Life Sciences and Technologies, Jelgava (Latvia)
The experiment was conducted to analyse the effect of fermented acid whey permeate on milk yield and composition in the lactating cows. Propionic acid bacteria and their metabolites have been used in the lactating cows feeding over decades, primarily to improve growth performance, feed conversation and milk production efficiency. Two groups of the lactating cows were arranged in the study: control group (n=50) and experimental group (n=50). Experimental group’s animals received 0.5 L of fermented whey permeate daily. Acid whey permeate was inoculated with the freeze-dried PS-4 (Propionibacterium freudenreichii subsp. shermanii, Chr.Hansen, Denmark) starter and fermented anaerobically for 48 hours at 20±2 ºC. Fat, protein, lactose and total solids concentration in acid whey permeate and fermented acid whey permeate was analysed by the standard methods, but propionic acid was detected by HPLC. Milk composition and quality indices were determined at the beginning of the study and each month during 6 months period. At the end of the study the feeding of fermented acid whey permeate was stopped, but milk composition and quality data were monitored additionally after one month. Milk fat, protein, lactose, total solids, urea concentration and somatic cell count were analysed by a near infrared spectroscopy. The variability in milk composition and quality data across trial was greater in the experiment group than in the control. Milk fat and somatic cell count were significantly different (p is less than 0.05) than other studied parameters in the experimental group cows’ milk. Milk yield and lactose concentration were tended to increase during feeding of fermented acid whey permeate in the lactating cows without significant differences between control and experimental groups. Fermented acid whey permeate as feed supplement improves energy metabolism for dairy cows which results in the higher milk yield and fat concentration.
Показать больше [+] Меньше [-]Influence of germination conditions and parameters on the content of total phenolic compounds and scavenging activity in germinated seeds
2020
Bernate, I., Latvia Univ. of Life Sciences and Technologies, Jelgava (Latvia). Faculty of Food Technology | Sabovics, M., Latvia Univ. of Life Sciences and Technologies, Jelgava (Latvia). Faculty of Food Technology | Tomsone, L., Latvia Univ. of Life Sciences and Technologies, Jelgava (Latvia). Faculty of Food Technology
Consumers are increasingly consuming sprouted seeds due to their low calories content, nutritional value, as well as beneficial effects on human health. Sprouts contain many bioactive compounds such as minerals, fibre, vitamin C, carotenoids and phenolic compounds. The aim of this study was to determine the effects of darkness, light and time total phenolic content and scavenging activity in alfalfa (Medicago sativa), radish (Raphanus sativus), broccoli (Brassica oleracea) and hemp (Cannabis sativa) seeds during germination. The seeds were washed, soaked in water by ratio of 2:1 (water : seeds) for 12±1 h and then germinated in light and dark conditions at a temperature of 22±2 °C and a relative humidity of 85±2% for different times (12, 24, 36 and 48 hours) in a climatic chamber ICH110 (Memmert, Germany). The quality changes of germinated seeds are determined by phenol content and scavenging activity. Un-germinated seeds were used as a control. The results of current studies show that after germination the highest increase in total phenols was in radish, broccoli and alfalfa seeds. The scavenging activity (SA) was higher after 48 hours of germination in all seed types compared to un-germinated seeds both in darkness and in light. This study shows that sprouted edible seeds are an excellent source of total phenolic compounds and has a high scavenging activity.
Показать больше [+] Меньше [-]The influence of technological peculiarities on fermented sausages’ quality and sensory properties
2021
Gramatina, I., Latvia Univ. of Life Sciences and Technologies, Jelgava (Latvia) | Sauka, J., Ādažu desu darbnīca, SIA., Ādaži, Ādaži Parish, Ādaži Municipality (Latvia) | Semjonovs, A., Ādažu desu darbnīca, SIA., Ādaži, Ādaži Parish, Ādaži Municipality (Latvia) | Strode, S., Latvia Univ. of Life Sciences and Technologies, Jelgava (Latvia) | Straumite, E., Latvia Univ. of Life Sciences and Technologies, Jelgava (Latvia)
Fermentation is one of the ancient technological processes used in food production which influences the shelf-life of meat and meat products, also significantly affects the sensory properties like aroma and flavour. The objective of the present study was to evaluate the elaborated technology for a new fermented sausage production on the product quality and sensory properties. Sausages were produced by the standard technology using glucono-delta-lactone or starter culture. The drying of samples differs from 3 to 4 weeks at the same conditions; samples were dried for 4 weeks which produced with the starter culture, and 3 weeks which produced with glucono-delta-lactone. The sausages were tested at the end of the production, analysing pH, water activity, moisture and salt content, as well as the presence of Listeria monocytogenes, colony forming units of Listeria monocytogenes and Enterobacteriaceae in the sausage samples were analysed. The sensory evaluation was organised after getting Listeria monocytogenes testing results. The moisture content, water activity and salt content significantly differed (p is less than 0.05) among samples, no differences were established in pH, taste and flavour liking. The presence of Listeria monocytogenes was not established in samples which indicates that the producer properly applies a hurdle technology in fermented sausage production. Sensory evaluation results showed higher scores for texture and appearance in fermented sausages with glucono-delta-lactone. The study results confirmed that fermented sausages with glucono-delta-lactone during 3 weeks of drying can achieve corresponding safety criteria and sensory properties which are set for semidry fermented sausages.
Показать больше [+] Меньше [-]Effect of nitrogen and sulphur fertilization on chlorophyll content in winter wheat
2017
Skudra, I., Latvia Univ. of Agriculture, Jelgava (Latvia). Faculty of Agriculture. Inst. of Agrobiotechnology | Ruza, A., Latvia Univ. of Agriculture, Jelgava (Latvia). Faculty of Agriculture. Inst. of Agrobiotechnology
Nitrogen management strategy in plant growth period based on chlorophyll content evaluation in plant can improve nitrogen usage efficiency and reduce environmental contamination. This study is aimed to determine the impact of different nitrogen and sulphur fertilizers rates on dynamics of chlorophyll content in winter wheat during vegetative growth and to determine the relationship between nitrogen and chlorophyll content and grain yield of winter wheat. Field trial involving a winter wheat (Triticum aestivum L.) variety ‘Kranich’ was conducted at the LUA Research and Study Farm Vecauce during a three-year period (2012-2015). The treatments were 0, 85, 153, 175+S21, 175 (in 2015), 187 N kg haE−1 and different nitrogen norms according to chlorophyll meter Yara N-tester (Konica Minolta Ltd.) data: 180, 150, 205 N kg haE−1 depending on the year. The results of the trial show that the maximum chlorophyll content in different plant parts was observed at the end of flowering stage. The chlorophyll content depended on the level of mineral fertilisation. The highest chlorophyll content in leaves, stems and ears was obtained by using additional sulphur in two trial years. Usage of chlorophyll meter Yara N-tester obtained the highest chlorophyll content in all analysed plant parts in one trial year. Chlorophyll content was significantly dependant on plant growth stage in stems in all trial years, in leaves in two trial years, and in ears in one year. Nitrogen fertilization significantly affected chlorophyll content in leaves and stems in one trial year. Close positive correlation was observed between grain yield and wheat plant chlorophyll content and average nitrogen concentration at the end of flowering stage in all three trial years.
Показать больше [+] Меньше [-]The characteristics of extruded faba beans (Vicia faba L.)
2016
Strauta, L., Latvia Univ. of Agriculture, Jelgava (Latvia). Faculty of Food Technology | Muizniece-Brasava, S., Latvia Univ. of Agriculture, Jelgava (Latvia). Faculty of Food Technology
Faba beans (Vicia faba L.) are an excellent protein source and should be more present in human diet, but due to their long cooking time, they are rarely used. So, in order to increase the accessibility of faba beans (Vicia faba L.), experiments were carried out to obtain new food products. Extrusion-cooking was chosen as the potential thermal cooking process and two different products were obtained. One was made exclusively from faba bean (Vicia faba L.) flour, while the second one was produced with a 50% addition of wheat flour to bean flour. Protein content, size, volume mass, pH and starch content for obtained products were analysed in order to characterise the products, as well as to see the differences from non-extruded faba beans (Vicia faba L.) and obtained samples. The experiments were carried out using faba beans (Vicia faba L.) obtained at Ltd. “Pure Horticultural Research Centre”. They were milled at Ltd. “Grauda spēks” and extruded with a twin screw extruder at Ltd. “Milzu”. The experiments showed that the extrusion process had decreased the protein content by 9%, but the starch content had risen by 13% with the addition of wheat flour. But, for sample, without added wheat flour differences were not significant. No significant size differences were observed in the obtained samples and pH values had no significant differences between extruded samples.
Показать больше [+] Меньше [-]Total content of phenolics and antioxidant activity in crispbreads with plant by-product addition
2017
Konrade, D., Latvia Univ. of Agriculture, Jelgava (Latvia). Faculty of Food Technology | Klava, D., Latvia Univ. of Agriculture, Jelgava (Latvia). Faculty of Food Technology
The objective of this study is to investigate the stability of total phenolic content (TPC) and antioxidant activity after high temperature and short time (HTST) extrusion cooking of a wheat and rice-based crispbreads with addition of apple, carrot and pumpkin by-products obtained after juice extraction and dried. Raw materials for crispbread production were wheat flour, rice flour, wheat bran (72%, 24% and 4% respectively) with addition of microwave–vacuum dried by-product powder in different amount (5%, 10%, 15%, 20%). Extrusion process was performed by using a laboratory singlescrew extruder GÖTTFERT 1 screw Extrusiometer L series (Germany). Total phenolic content (TPC) was determined using the Folin Ciocalteu method. Antioxidant activity was evaluated by free radical 2, 2-diphenyl-1-picrylhydrazyl (DPPH) antioxidant scavenging activity using a modified colorimetric method. Comparing different raw formulations, it was observed that the TPC of the apple by-product flour was significantly higher (p is less than 0.05) than in carrot and pumpkin flour. TPC in cereal-based crispbread was 36.06±1.15 before extrusion and 13.90±1.01 mg GAEgE-1 DW (milligram Gallic acid equivalent per 100 g of dry weight (mg GAE 100 gE−1 DW) after extrusion. Addition of apple BPF increased TPC in crispbreads to 106.25±2.08, carrot BPF 84.73±3.45 and pumpkin BPF to 108.82±1.04 mg GAEgE−1 DW. Antioxidant activity of control sample was 1.07±0.01mg TE (Trolox equivalents) gE−1 DW but in samples with addition of 20% apple by-products, it reached 3.77±0.02 TE gE−1 DW for samples with 20% carrot by-products reached 2.52±0.03TE gE−1 DW and for samples with 20% pumpkin by-products reached 3.77±0.02 TE gE−1 DW.
Показать больше [+] Меньше [-]Rhizobium sp. – a potential tool for improving protein content in peas and faba beans
2017
Senberga, A., Latvia Univ. of Agriculture, Jelgava (Latvia) | Dubova, L., Latvia Univ. of Agriculture, Jelgava (Latvia) | Alsina, I., Latvia Univ. of Agriculture, Jelgava (Latvia) | Strauta, L., Latvia Univ. of Agriculture, Jelgava (Latvia)
Legume seed inoculation prior to sowing is a well-known practice in agriculture. Nitrogen fixation, due to the symbiotic relationship between legumes and rhizobia, improves the productivity of legumes. Rhizobia strain specificity can be observed very often, leading to differences in the total protein content. In this study two faba bean cultivars (‘Karmazyn’ and ‘Bartek’) and five pea cultivars (‘Retrija’, ‘Zaiga’, ‘Lāsma’, ‘Vitra’ and ‘Bartek’) were tested using various rhizobia strains. In addition, strain effectivity was observed in four different soil types. Overall, the protein content increase was observed after seed inoculation with Rhizobium sp. Rhizobia strain and plant cultivar interaction specification was observed. Plant cultivar appeared to have a decisive role in the formation of protein content when inoculated with Rhizobium sp. From these pilot experiments, it can be concluded that, when choosing Rhizobium sp. strains for legume inoculation, soil type also should be considered. Rhizobia has the potential to be used as a commercial preparation intended for increasing legume protein content, alongside with increased legume yield; however, different rhizobia strains should be mixed together to achieve the optimal result.
Показать больше [+] Меньше [-]The correctness problems in applying inductive statistics in economics and agriculture
2017
Jaunzems, A., Ventspils Univ. College (Latvia) | Balode, I., Aleksandras Stulginskis Univ., Akademija, Kauno reg. (Lithuania)
In the article “Professor Tinbergen’s Method” (Keynes J. M. Professor Tinbergen’s Method. − The Economic Journal. 1939. Vol. 49. No. 195) John Maynard Keynes expressed critical notes concerning insufficient scientific level of the Jan Tinbergen’s results obtained with the help of econometric methods. The conclusion of present research is that the critical appraisal of econometric applying given by John Maynard Keynes in 1939 can be completely assigned to many published in Latvia research in economics and business done by inductive statistics because scientists carelessly apply the linear regression model in absence of the knowledge a priori required by proper theorems and algorithms. Moreover, many times there is no sense even to speak about stochastic experiment because the most important condition − ceteris paribus does not fulfil, namely, economic environment is not homogeneous enough. As the result, the causal inferences derived from Regression Report are not scientifically justified. The second conclusion is that the objective criticism in econometrics applications area in order to keep the satisfactory level of scientific correctness and scientific ethics in Latvia has to be established. We also assert that the applications of inductive econometrics in agriculture are much more justified due to possibility to repeat the stochastic experiments many times in constant circumstances like in physics and mechanics. The meta-target of present article is to remind the protests of John Maynard Keynes to the careless utilization of econometric theorems and to raise a wide discussion about the problems of correctness in applying inductive statistics in economics and agriculture in Latvia.
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