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The Influence of Germinated Hull-less Barley Sordough Fermentation Conditions on the Microbiota Development 全文
2021
Kl̦ava, Dace | Poisa, Iveta | Reidzane, Sanita | Kince, Tatjana | Kazantseva, Jekaterina | Traksmaa, Anna
Sourdough plays an important role in quality assurance, especially during developing wholegrain wheat bread products. The value of barley and hull-less barley grains is determined by the low lipid and high carbohydrate (starch and resistant starch) content, balanced amino acid profile, dietary fibre and phenolic compounds. During germination (24 h) the amount of sugar, amino acids and vitamins increase in the grains. Therefore, it could be optimal environment for microbiota growth in sourdough. The goal of the research was to find optimal technological parameters and to study microorganism growth dynamic during the fermentation of sourdough with germinated hull-less barley. The study was performed using three steps of fermentation, with different temperature and time parameters. At each step pH, dynamics of lactic acid bacteria (LAB), yeast-like fungi and total plate count (TPC) growth were determined using standard methods. The results of the study showed that the optimal fermentation conditions for the first stage are 48 h and 26 ± 1 °C, for the second stage 8 h and 26 ± 1 °C and for the third stage 20 h and 28 ± 1 °C. During fermentation of the sourdough, the pH 3.91 is reached, LAB 8.8 log₁₀ CFU g⁻¹, and the yeast-like fungi 8.7 log₁₀ CFU g⁻¹ was determined. Obtained data show that more than 80 bacteria and 50 microscopic fungal species were detected in hull-less barley flour, but after germination their diversity decreased and in the germinated hull-less barley sourdoughs dominated species were Pediococcus pentosaceus.
显示更多 [+] 显示较少 [-]Determination and Optimization of Feeding Device Parametres in the Plant for Preparing Liquid Feed Mixtures 全文
2021
Solonshchikov, Pavel | Savinykh, Peter | Ivanovs, Semjons
Feeding young animals is a very important stage during their growing-up period, but in order to provide them with essential nutrients, they are fed with liquid feeds, whole milk substitute in particular (WMS). The technique for reconstituting WMS consists of dissolving it in water followed by mixing, but it is significant to follow the cooking recipe strictly, so it is necessary to develop a system with a feeding (dosing) device that will make it possible to solve this problem. Theoretical and experimental studies of the feeding device have been conducted in order to optimize the technological process of mixing liquid feed. Theoretically, the quality of determining the mixture during dosing was established for the purpose of further research. The influence of the design and technological parameters of the feeding device was experimentally studied, and its efficiency was evaluated. It was found that as the inclination angle α increases from 67,5⁰ to 70⁰, the rotation speed n being from 850 to 1500 min⁻¹, the maximum probability of staying in the tolerance field ΔP=96% is reached, and feed discharge Q ranges from 540 to 660 kg h⁻¹. The research makes it possible to develop a feeding device at the design stage, meeting the requirements of the recipe, having high discharge rates and the lowest energy consumption.
显示更多 [+] 显示较少 [-]Analysis of Financial Support Instruments for Social Enterprises in Latvia 全文
2021
Licite-Kurbe, Lasma | Gintere, Dana
Analysis of Financial Support Instruments for Social Enterprises in Latvia 全文
2021
Licite-Kurbe, Lasma | Gintere, Dana
Social enterprises have positive effect on sustainable development, and they have become an important instrument for solving social problems (especially in rural areas), as the national and local governments alone cannot solve all such problems. To foster the development of social entrepreneurship, Latvia has introduced several support instruments for social enterprises, which include tax relief, privileged procurement contracts, grants, as well as non-monetary kinds of support. However, social entrepreneurs often point out that support from the national and local governments is insufficient, while the support instruments stipulated in the Social Enterprise Law are not widely used. Therefore, the aim of the research is to analyse national and local government support instruments for social enterprises in Latvia. The research found that the most important financial instrument fostering the development of social entrepreneurship in Latvia is a grant scheme administered by the Ministry of Welfare and the JSC Development Finance Institution Altum, which is available in the range of EUR 5000 to 200000 for investment and working capital. In the period 2017-2020, 94 social entrepreneurship projects with a total budget of EUR 6 million were supported, which could be viewed as significant financial support. In contrast, immovable property tax relief, exemption from enterprise income tax (on profits) and relief from this tax for several categories of non-business expenses are considered by social entrepreneurs to be an insignificant kind of support. There is also lack of experience and practice regarding the inclusion of social criteria in public procurement in Latvia.
显示更多 [+] 显示较少 [-]Analysis of financial support instruments for social enterprises in Latvia 全文
2021
Licite-Kurbe, L., Latvia Univ. of Life Sciences and Technologies, Jelgava (Latvia) | Gintere, D., Latvia Univ. of Life Sciences and Technologies, Jelgava (Latvia)
Social enterprises have positive effect on sustainable development, and they have become an important instrument for solving social problems (especially in rural areas), as the national and local governments alone cannot solve all such problems. To foster the development of social entrepreneurship, Latvia has introduced several support instruments for social enterprises, which include tax relief, privileged procurement contracts, grants, as well as non-monetary kinds of support. However, social entrepreneurs often point out that support from the national and local governments is insufficient, while the support instruments stipulated in the Social Enterprise Law are not widely used. Therefore, the aim of the research is to analyse national and local government support instruments for social enterprises in Latvia. The research found that the most important financial instrument fostering the development of social entrepreneurship in Latvia is a grant scheme administered by the Ministry of Welfare and the JSC Development Finance Institution Altum, which is available in the range of EUR 5000 to 200 000 for investment and working capital. In the period 2017‒2020, 94 social entrepreneurship projects with a total budget of EUR 6 million were supported, which could be viewed as significant financial support. In contrast, immovable property tax relief, exemption from enterprise income tax (on profits) and relief from this tax for several categories of non-business expenses are considered by social entrepreneurs to be an insignificant kind of support. There is also lack of experience and practice regarding the inclusion of social criteria in public procurement in Latvia.
显示更多 [+] 显示较少 [-]A Case-study: Temperature Distribution and Heat Penetration in Steam-air Retort, Using Glass Jars and Retort Pouches 全文
2021
Raits, Evalds | Pinte, Lasma | Kirse-Ozolina, Asnate | Muizniece-Brasava, Sandra
Retort thermal sterilization of canned food is a technology, which allows preserving food products by applying heat on packaged food in retorts (autoclaves) at temperatures up to 121 °C. The thermodynamics of the processes in the retort are influenced by the product stacking method in the basket and packaging material. The aims of this study were: 1) to analyse and compare temperature distribution (TD) and the slowest to heat location in the steam-air retort stacked with glass jars and with retort pouches; 2) to analyse and compare commercial product heat penetration (HP) characteristics in glass jars and retort pouches. Temperature measurements were performed with wireless thermocouples. The come-up time (heating phase) required to achieve in the retort temperature uniformity criteria of ±0.5 °C, is 28 min when the retort is stacked with glass jars, and 24 min when the retort is stacked with retort pouches. Total calculated process time (holding phase), necessary to achieve the sterilization value (F₀ of 3 min), for sample in glass jars was 67 min, but in retort pouches – 62 min. The overall sterilization process time difference between two considered packaging types was 9 min, which is significant amount of time in the context of commercial processing. The study clearly shows the necessity to perform the Temperature Distribution and Heat Penetration study, as each packaging material, stacking method and product will affect sterilization process thermodynamics and, therefore, the overall process time and consequently - the safety of food product.
显示更多 [+] 显示较少 [-]Theoretical and Experimental Investigation of the Thermal Inactivation of Thermoanaerobacterium Thermosaccharolyticum and Geobacillus Stearothermophilus in Different Canned Food Matrices 全文
2021
Raits, Evalds | Raita, Svetlana | Kirse-Ozolina, Asnate | Muizniece-Brasava, Sandra
In the canning industry, thermal preservation processes typically are designed based on Clostridium botulinum thermal destruction kinetics. However, some bacteria can still survive, necessitating implementation of stricter timetemperature regimen for sterilization process. The aim of this study was to compare processing effectiveness at F₀ (sterilization value) 8 ±1 min from the perspective of the vegetable-based product canning facility, while analyzing the inactivation, viability, and recovery of thermophilic bacteria. Four commercial products [tomato soup and rassolnik soup - acidified food (AF), and mushroom soup and pea porridge - low-acid food (LACF)] with different heat transfer characteristics (convection and conduction) were inoculated with 6.6 log₁₀ spores/ml Geobacillus stearothermophilus LMKK 244 (reported as DSM 6790 and ATCC 10149 in other collections) and 4.8₁₀ log spores/ml Thermoanaerobacterium thermosaccharolyticum DSM 571 spore suspensions. Food samples contaminated with bacterial spores were processed in a steam-air retort at 118 °C for 75 min. G. stearothermophilus and T. thermosaccharolyticum growth was not detected in AF samples (pH = 4.4 and 4.5), but was observed in LACF samples (pH = 5.1 and 5.8). Practical evaluation showed that T. thermosaccharolyticum did not survive thermal processing, which was verified using a presence/absence test after incubation at 55 °C. G. stearothermophilus did not survive thermal processing, but recovered in pea porridge (pH = 5.8) during incubation. Our observations showed that food pH is a crucial factor determining microorganism survival during heat treatment and may be used by the vegetable-based product canning facilities to improve the food sterilization conditions.
显示更多 [+] 显示较少 [-]Evaluation of patatin content in proteins of potato genotypes grown in Latvia 全文
2021
Berga, Dace | Sterna, Vita | Sokolova, Elina | Taskova, Inese | Seile, Sanita | Dimante, Ilze | Skrabule, Ilze
Potato proteins contains essential amino acids in considerably high concentration, therefore potatoes are considered to be one of the most valuable plant origin food for human consumption. Patatin forms one of the largest group of potato proteins with high potential to be used in food industry as a novel food. This study has been performed to approbate patatin determination method for evaluation of protein quality of potato genotypes, as well as evaluate patatin relative abundance (PRA) for breeding programmes to create in the future potato cultivars with higher value and potential to develop new products. The evaluation of patatin was performed in following steps– extraction proteins from potato, determination of patatin concentration and calculation of its relative abundance in proteins. Separation of patatin from potato tubers was made using extraction by SDS extraction buffer and determination of patatin in organically and conventionally (with differnt N suply) grown samples of 20 potato genotypes. The results of one-year study showed that patatin relative abundance of different cultivars varied from 1.65% to 50.2% and it was significantly different among genotypes. The nitrogen content of soil and maturity type of potato did not affect PRA significantly. Results provide impetus for further research.
显示更多 [+] 显示较少 [-]Influence of Veneer Density on Plywood Thickness and Some Mechanical Properties 全文
2021
Kūliņš, Laimonis | Meija, Anete | Roziņš, Rihards | Liepa, Kārlis Hermanis | Spulle, Uldis
It has been common knowledge that as the density of wood increases, the mechanical properties also improve. In turn, the density of wood depends on many factors, including the wood moisture content, location and cross-section in the trunk, the type of treatment and the parameters of technological processes. There is a great deal of research reported in the scientific literature on the effect of solid wood density on mechanical properties for different wood species as well as for structural timber. However, no research data can be found related investigation of the influence of veneer density on the properties of the birch plywood. In the present study, researching the properties of 7-ply birch plywood (thickness 9 mm), it was concluded that as the density of veneers increases, the bending properties of plywood in the direction of wood fibers (covered veneers) increases. When determining the plywood gluing quality, similar tendencies have been observed. For plywood with a lower density in all veneer plies the gluing quality (tensile-shear test) for perpendicular wood fiber veneers increases in the direction from the symmetry axis or middle veneer to the plywood outer plies, which can be explained by the fact that the outer plies become denser at the time of the hot pressing process. The results of the study will allow birch plywood manufacturers in direct production, sort veneers by density, to produce plywood with very predictable gluing quality, plywood thickness and mechanical properties in bending.
显示更多 [+] 显示较少 [-]Slaughter Results, Meat Chemical Composition and pH of Aberdinangus, Hereford and Limousin bulls 全文
2021
Muizniece, Inga | Kairisa, Daina
Beef production must combine the interests of both producers and consumers, taking into account the sustainable use of environmental resources. The aim of the study was to analyze and compare the slaughter results, meet chemical composition and pH value of three beef breeds – Aberdinangus (AA), Hereford (HF) and Limousin (LI) bulls. The bulls were fattened on Latvian and Lithuanian farms, mainly using grass forage. The breed and age of bulls before slaughter significantly affected all slaughter results, except for fat class. From the meat chemical composition traits, the bull breed and age before slaughter had a significant effect only on the protein content. LI bulls showed the highest carcass weight 301.1±6.8 kg (p<0.05), dressing percentage 58.2±1.1% (p<0.05) and conformation score 3.56±0.18 points. The best fattened carcasses were obtained from AA bulls - 2.43±0.20 points. Muscle samples of musculus longissimus (M. longissimus) bulls of LI breed showed higher content of moisture (72.0±1.0%), protein (23.0±0.2%), ash (1.1±0.0%) and cholesterol (56.7±6.6 mg 100 g⁻¹). AA breed bulls showed higher total fat (6.6±1.2%) and iron content (13.1±0.6 mg). The highest pH was observed in the meat obtained from AA bulls – 6.0±0.1, LI and HF breed bulls showed pH 5.8±0.0 and 5.8±0.1 respectively. Correlation analysis showed a significant, strong positive correlation between cold carcass weight and dressing percentage for AA and LI bulls, r=0.90 and r=0.88, respectively. For LI breed bulls, a strong positive correlation was also found between the cold carcass weight and the conformation score (r=0.98, p<0.01).
显示更多 [+] 显示较少 [-]Impact of Crop Rotation and Soil Tillage on the Severity of Winter Wheat Leaf Blotches 全文
2021
Bankina, Biruta | Bimšteine, Gunita | Arhipova, Irina | Kaņeps, Jānis | Darguža, Madara
Impact of Crop Rotation and Soil Tillage on the Severity of Winter Wheat Leaf Blotches 全文
2021
Bankina, Biruta | Bimšteine, Gunita | Arhipova, Irina | Kaņeps, Jānis | Darguža, Madara
Reduced tillage is considered as one of the main tools to save biological diversity; however, it increases pressure of diseases, including wheat leaf blotches. The aim of present study was to clarify the impact of reduced soil tillage on the development of winter wheat leaf blotches in different schemes of crop rotation. The impact of different growing technologies on the severity of winter wheat disease was evaluated in a two-factorial experiment: A – soil tillage system, and B – different combinations of wheat pre-pre-crop and pre-crop (wheat, oilseed rape, barley and faba beans). Diseases were assessed every 10 days approximately and total impact of diseases was evaluated by calculating AUDPC (Area under Diseases Progress Curve). Tan spot, caused by Pyrenophora tritici-repentis was dominated disease over the long period, regardless of meteorological conditions. Development of Septoria leaf blotch was not influenced by neither crop rotation nor soil tillage. The level of tan spot was essentially higher after wheat, regardless of the pre-pre-crop. Reduced soil tillage promoted severity of tan spot. Ploughing mitigated effect of previous crops and differences in tan spot level were insignificant. Despite many positive effects of conservation tillage, increasing of fungicide treatment could be necessary, in conditions, when the tan spot is most devastating and widespread wheat disease.
显示更多 [+] 显示较少 [-]Impact of crop rotation and soil tillage on the severity of winter wheat leaf blotches 全文
2021
Bankina, B., Latvia Univ. of Life Sciences and Technologies, Jelgava (Latvia) | Bimsteine, G., Latvia Univ. of Life Sciences and Technologies, Jelgava (Latvia) | Arhipova, I., Latvia Univ. of Life Sciences and Technologies, Jelgava (Latvia) | Kaneps, J., Latvia Univ. of Life Sciences and Technologies, Jelgava (Latvia) | Darguza, M., Latvia Univ. of Life Sciences and Technologies, Jelgava (Latvia)
Reduced tillage is considered as one of the main tools to save biological diversity; however, it increases pressure of diseases, including wheat leaf blotches. The aim of present study was to clarify the impact of reduced soil tillage on the development of winter wheat leaf blotches in different schemes of crop rotation. The impact of different growing technologies on the severity of winter wheat disease was evaluated in a two-factorial experiment: A – soil tillage system, and B – different combinations of wheat pre-pre-crop and pre-crop (wheat, oilseed rape, barley and faba beans). Diseases were assessed every 10 days approximately and total impact of diseases was evaluated by calculating AUDPC (Area under Diseases Progress Curve). Tan spot, caused by Pyrenophora tritici-repentis was dominated disease over the long period, regardless of meteorological conditions. Development of Septoria leaf blotch was not influenced by neither crop rotation nor soil tillage. The level of tan spot was essentially higher after wheat, regardless of the pre-pre-crop. Reduced soil tillage promoted severity of tan spot. Ploughing mitigated effect of previous crops and differences in tan spot level were insignificant. Despite many positive effects of conservation tillage, increasing of fungicide treatment could be necessary, in conditions, when the tan spot is most devastating and widespread wheat disease.
显示更多 [+] 显示较少 [-]Impact of High-pressure Impregnation and Fire Protective Coatings on the Reaction to Fire Performance of Birch Plywood 全文
2021
Rudzīte, Sanita | Bukšāns, Edgars
Impact of High-pressure Impregnation and Fire Protective Coatings on the Reaction to Fire Performance of Birch Plywood 全文
2021
Rudzīte, Sanita | Bukšāns, Edgars
Birch plywood has a wide range of applications for interior and exterior use. The demand for plywood with improved fire protection properties and good visual appearance is increasing year by year. The impregnation at high pressure of the whole plywood panels is one of the options to achieve it. The aim of this study was to develop good visual looking birch plywood product for interior design purposes as well evaluate different influencing factors to reaction to fire properties of fire-retardant treated birch plywood. This study consists of three parts. At the first stage, high pressure industrially impregnated plywood properties were studied by two influencing factors – distribution of fire retardant in plywood panel plane and sanding process influence on reaction to fire performance of product. At the second stage, seven different industrial finishing systems were selected for covering high-pressure impregnated birch plywood and their effect on fire reaction performance was studied. In addition, two surface coating systems were studied on standard birch plywood substrate. At the third stage, intumescent coating consumption effect on reaction to fire performance was studied. The reaction to fire performance of birch plywood was evaluated by performing a flammability test using the Single Burning Item test according to EN 13823:2010. It was found that high pressure impregnation of plywood cannot ensure even saturation of fire retardant throughout the sheet, which significantly affects the fire performance of product. The impact of different finishing materials to reaction to fire performance has been described by the results of this research.
显示更多 [+] 显示较少 [-]Impact of high-pressure impregnation and fire protective coatings on the reaction to fire performance of birch plywood 全文
2021
Rudzite, S., Latvijas Finieris, JSC, Riga (Latvia) | Buksans, E., Latvia Univ. of Life Sciences and Technologies, Jelgava (Latvia)
Birch plywood has a wide range of applications for interior and exterior use. The demand for plywood with improved fire protection properties and good visual appearance is increasing year by year. The impregnation at high pressure of the whole plywood panels is one of the options to achieve it. The aim of this study was to develop good visual looking birch plywood product for interior design purposes as well evaluate different influencing factors to reaction to fire properties of fire-retardant treated birch plywood. This study consists of three parts. At the first stage, high pressure industrially impregnated plywood properties were studied by two influencing factors – distribution of fire retardant in plywood panel plane and sanding process influence on reaction to fire performance of product. At the second stage, seven different industrial finishing systems were selected for covering high-pressure impregnated birch plywood and their effect on fire reaction performance was studied. In addition, two surface coating systems were studied on standard birch plywood substrate. At the third stage, intumescent coating consumption effect on reaction to fire performance was studied. The reaction to fire performance of birch plywood was evaluated by performing a flammability test using the Single Burning Item test according to EN 13823:2010. It was found that high pressure impregnation of plywood cannot ensure even saturation of fire retardant throughout the sheet, which significantly affects the fire performance of product. The impact of different finishing materials to reaction to fire performance has been described by the results of this research.
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