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Methodology of dietary fibre determination in grain products
2009
Ozolina, V., Latvia Univ. of Agriculture, Jelgava (Latvia) | Gramatina, I., Latvia Univ. of Agriculture, Jelgava (Latvia) | Kunkulberga, D., Latvia Univ. of Agriculture, Jelgava (Latvia)
The dietary fibre is edible parts of plants' carbohydrates that are resistant to digestion in human small intestine. Diets naturally rich in dietary fibre support to prevent constipation, improve gastrointestinal health, glucose tolerance and the insulin response, and reduce the risk of colon cancer, hyperlipidemia, hypertension and other coronary heart disease risk factors. About 45% of the dietary fibre intake comes from grains and grain mixtures. In Latvia, there are neither data, nor investigations of the dietary fibre content in grain products during processing and in the end products in which manufacturers and consumers are interested. The aim of this paper was an approval of dietary fibre determination methodology by using analytical equipment the Full option science system (FOS) Analytical Fibertec E 1023. The dietary fibre determination experiments were carried out in the Research Laboratory of the Department of Food Technology at the Latvia University of Agriculture in 2009. The Total Dietary Fibre (TDF) content was analyzed in the samples of rye whole grain flour, rye whole grain bread, and wheat biscuit. Experiments showed that the fibre content in rye whole grain flour is 13.8 g 100 gE-1, in rye whole grain bread - 11.6 g 100 gE-1, and in the wheat biscuit - 1.9 g 100 gE-1. Reached data are comparable with results of other researchers' data.
Afficher plus [+] Moins [-]Stinging nettle - the source of biologically active compounds as sustainable daily diet supplement
2014
Zeipina, S., Latvia Univ. of Agriculture, Jelgava (Latvia);Pure Horticultural Research Centre, Pure parish, Tukuma municipality (Latvia) | Alsina, I., Latvia Univ. of Agriculture, Jelgava (Latvia) | Lepse, L., Pure Horticultural Research Station, Pure parish, Tukuma municipality (Latvia)
Environmental conditions and climate change on a global scale affects the overall agriculture and food supply. Consumers demand for vegetables with high nutritional value is increasing. Consumers more and more are thinking about a healthy and balanced diet, but it is not easy to provide year-round fresh vegetables. Nettle (Urtica) leaves traditionally are used in early spring as a leafy vegetable in salads and soups. Young leaves before flowering are used for human consumption. Nettle contains a lot of vitamins and biologically active compounds. The research aim was to evaluate different stinging nettle clones, which grow in Pūre village (Tukuma district, Latvia). Samples were collected, when shoots were 10 – 15 cm long. Content of chlorophyll, carotenoids and anthocyanins in five nettle clones leaves were analysed. Biochemical analysis was done in Latvia University of Agriculture, Institute of Soil and Plant Science laboratory. Differences were observed between all clones. Significant difference between genotypes was observed in anthocyanins content, but not in chlorophylls and carotenoids content. Higher anthocyanins content was observed in samples, which grow in places with low nitrogen and phosphorus content. Content of biochemical compounds can influence some metal ions, environmental and other factors.
Afficher plus [+] Moins [-]Purification of egg yolk oil obtained by solvent extraction from liquid egg yolk
2014
Kovalcuks, A., Latvia Univ. of Agriculture, Jelgava (Latvia)
There are different methods of egg yolk oil extraction, but still solvent extraction is commonly used. Due to the high cost of egg yolk powder production, extraction of lipids from liquid egg yolk remains very topical. Crude egg yolk oil obtained by solvent extraction from liquid egg yolk contains high amount of water which can decrease shelf life of egg oil promoting lipid oxidation. High concentration of residual solvents limits the usage of egg oil in food or in cosmetics due to the health risks. The aim of this study is to purify egg yolk oil obtained by solvent extraction from liquid egg yolk. Results show that it is possible to decrease the water content in egg oil from 14.26 ± 1.29% to 0.88 ± 0.13% by eliminating lecithin from egg oil. Solvent evaporation in the rotary film evaporator under the vacuum cannot remove solvents completely from the extract, but nitrogen streaming through the extract as a last step in evaporation process removes solvent residues, leaving behind high quality egg yolk oil suitable for food application.
Afficher plus [+] Moins [-]Corticosteroid-induced alteration in liver function in dogs and its decrease possibilities
2014
Kondratjeva, J., Latvia Univ. of Agriculture, Jelgava (Latvia) | Birgele, E., Latvia Univ. of Agriculture, Jelgava (Latvia)
Nowadays excessively used corticosteroids in veterinary medicine induce steroid hepatopathy in dogs (Canis lupus familiaris). The objective of this study was to determine the possibility of the hepatoprotectants to decrease the corticosteroid-induced alteration in such dogs’ blood serum enzymes as alaninaminotransferase (ALAT), gammaglutamyltranferase (GGT), alkaline phosphatase (AP) and corticosteroid-induced thermostable alkaline phosphatase (cAP). The study took place in private veterinary clinics in Riga, Latvia, during 2013, with the permission of dogs’ owners. Twenty eight animals, which received corticosteroids due to present diagnosis, were divided into two groups. In the first group long-lasting corticosteroid methylprednisolone acetate injection was used once, while in the second group the hepatoprotectants were used after the injection of corticosteroids. It was discovered that after 14 and after 30 days of hepatoprotectants use, blood enzymes were significantly lower (p is less than 0.05) than in dogs that did not receive hepatoprotectants. In both groups the enzyme values did not reach the reference limits. The study is set to investigate further if and when the values reach the reference limits.
Afficher plus [+] Moins [-]Factors affecting productivity and cost of solid biofuel in mechanized forest ditch cleaning
2014
Lazdins, A., Latvian State Forest Research Inst. Silava, Salaspils (Latvia) | Kaleja, S., Forest Sector Competence Centre, SIA, Riga (Latvia) - MNKC | Zimelis, A., Latvian State Forest Research Inst. Silava, Salaspils (Latvia)
The study represents results of productivity studies of mechanized ditch cleaning using Ponsse Fox harvester adapted to multi-tree handling H6 head in forest drainage systems managed by Joint stock company “Latvia state forests”. The aim of the study is to evaluate productivity of extraction of biomass from ditches depending on working method and to estimate factors affecting prime-cost of biofuel in mechanized harvesting. The study results demonstrate that the 2nd method (mechanized extraction of roundwood and following motor-manual cleaning of remaining vegetation) is the most efficient solution for mechanized cleaning of ditches. Benefits of the 2nd method are smaller costs of undergrowth removal and bigger output of solid biofuel. Ponsse Fox harvester demonstrated sufficient work quality and productivity in the trials; however, it would be wise to use heavier harvesters or caterpillar excavator based harvesters in ditch cleaning. Using the 2nd method, a harvester can extract about 227 ha of ditches (23,000 m3 ) annually.
Afficher plus [+] Moins [-]Evaluation of cumulative air pollution in Riga and Liepaja with cumulative pollution index method
2014
Kalnins, V., Latvia Univ. of Agriculture, Jelgava (Latvia) | Straupe, I., Latvia Univ. of Agriculture, Jelgava (Latvia) | Sudars, R., Latvia Univ. of Agriculture, Jelgava (Latvia)
Cumulative air pollution – synergy between different pollutants and environmental factors is one of the hardest to evaluate factors in the air quality monitoring field. The evaluation of cumulative effects is hindered by a lack of verified analytical frameworks. Currently used methods are relatively simple and use statistical models with small fixed number of pollutants in association with different factors. There is almost no one solution for direct, on-site cumulative effect measurements. The alternative is the use of Cumulative Pollution Index (CPI) method – solution designed for cumulative effect calculation from bioindication and air quality measurement data. However, this method is completely new and has never been used in the air pollution evaluation activities. Therefore, the objective of this study was to evaluate the opportunity to use CPI method as a cumulative pollution evaluation tool in air quality monitoring by doing measurements of cumulative effect in several air quality measurement stations in two cities of Latvia – Liepaja and Riga. Results show that Cumulative Pollution Index method is not only usable in air quality monitoring as a tool for cumulative effect evaluation, but can reveal new facts about air pollution and ways how it affects human and ecosystem health, – such climatic and environmental factors as humidity and temperature are more important than interactions between individual pollutants and can be considered main elements in forming of cumulative pollution impact.
Afficher plus [+] Moins [-]Metal uptake from contaminated soils by some plant species - radish, lettuce, dill
2013
Stapkevica, M., University of Latvia, Riga (Latvia) | Vincevica-Gaile, Z., University of Latvia, Riga (Latvia) | Klavins, M., University of Latvia, Riga (Latvia)
Plants are components of ecosystem that transfer elements from abiotic to biotic environments. Several elements, such as As, Cd, Hg, Pb, can be considered as food chain contaminants. Simultaneously, some essential micronutrients (e.g., Cu, Cr, Ni, Zn) at high concentrations may become toxic to both, plants and animals. To secure the aim to describe the uptake of metals by food crop species such vegetables, as radish Raphanus sativus L., leafy lettuce Lactuca sativa L. and dill Anethum graveolens L., were grown in soils of various grading composition and type. There were five soil types selected. A part of soils was contaminated with copper sulphate solution at different target concentrations, while another part was contaminated with mixture of metal (Pb, Cd, Cu, Zn) compounds. In half of treated soil samples the solution of humic substances was added. Harvested vegetables were dried, and after wet digestion with nitric acid quantitative analysis of metal concentrations was performed by use of atomic absorption spectrometry. The highest concentration of copper was detected in vegetable samples grown in soils with less organics, thereby indicating the importance of soil organic matter to metal transfer routes and accumulation rates in plants. Analysis of lettuce grown in soils contaminated with the mixture of metal compounds revealed that zinc was a metal absorbed more intensively, but metal uptake and accumulation was less intensive from peat if compared with other soils.
Afficher plus [+] Moins [-]Evaluation of butter oil oxidative stability and nutritional value affected by cow feeding
2013
Antone, U., Latvia Univ. of Agriculture, Jelgava (Latvia) | Sterna, V., Latvia Univ. of Agriculture, Jelgava (Latvia) | Zagorska, J., Latvia Univ. of Agriculture, Jelgava (Latvia)
Nutritional value and shelf life of milk and dairy products depend on the composition and stability of their constituents. The aim of the present study was to evaluate the effects of carrots as cow feed carotenoid source on butter oil fatty acid (FA) composition and oxidative stability. Milk was obtained from one trial group (TG; n=5) and one control cow group (CG; n=5) in a conventional dairy farm in Latvia. TG cows received carrots 7 kg per cow per day; the length of the supplementation period was 39 days. The stability of butter oil exposed to sunlight (3h) and held for 14 days in the temperature of 60 °C was analyzed by peroxide value method. The changes of the FA content and ratios in TG milk fat were more positive with respect to the fat nutritional value as observed in CG – stronger increase in the content of polyunsaturated FA (p is less than 0.05), and in the ratio between stearic and palmitic acids (p is less than 0.05); also a tendency was seen of increasing content of short and monounsaturated FA, as well as decreasing the ratio between ω6 and ω3 FA groups. Oxidative stability of the carrot supplemented cow group’s milk butter oil samples that were collected after 25- day trial period, exposed to sunlight (3h) and stored at a temperature of 60 °C was significantly (p is less than 0.05) higher compared to CG samples. After the 39-day long trial period stability difference was not significant, despite the tendency that average polyunsaturated FA content in TG samples was higher compared to the control.
Afficher plus [+] Moins [-]Investigation of physically-chemical parameters of conventional and organic hull-less barley harvested in Latvia
2013
Kalnina, S., Latvia Univ. of Agriculture, Jelgava (Latvia) | Rakcejeva, T., Latvia Univ. of Agriculture, Jelgava (Latvia) | Kunkulberga, D., Latvia Univ. of Agriculture, Jelgava (Latvia)
The main purpose of the research was to investigate the physically-chemical parameters of organic and conventional hull-less barley (Hordeum vulgare) harvested in Latvia. In the experiment the following hull-less barley harvested in 2012 from the State Priekuli Plant Breeding Institute (Latvia) was used: ‘Irbe’, PR4651, PR3808.21 and PR5099. The following quality parameters of grain – protein, starch, the bulk density and β-glucan content – were measured by standard methods – Infratec™ 1241 Grain Analyser (Denmark) corresponding to ISO 12099; thousand-grain weight (TGW) (ISO 520:2010); the falling number (ISO 3093:2009); moisture content (LVS 272:2000) were also determined. In the present experiments no significant differences in protein, moisture, starch, β-glucan content and TGW were detected, however, significant differences in the bulk density of all analyzed hull-less barley samples were established. The lower analyzed parameter value of 780 ± 1 g LE-1 was obtained for the conventional and organic hull-less barley PR 5099. However, the higher bulk density value of 821 ± 1 g LE-1 was obtained in the conventional hull-less barley variety ‘Irbe’. No significant differences in the bulk density of conventional and organic hull-less barley ‘Irbe’, PR4651 and PR3808.21 were found. Significant differences in the falling number were detected in the analyzed hull-less barley samples harvested in the conventional and organic farming. The lower falling number value was obtained in the organic hull-less barley line PR 5009 – 81 ± 4 s, the higher in the conventional and organic hull-less barley line PR 3808.21 as 362 ± 5 s and 373 ± 2 s, respectively.
Afficher plus [+] Moins [-]Nutritional value and sensory properties of yoghurt enriched with barley grains and malt extract
2013
Beitane, I., Latvia Univ. of Agriculture, Jelgava (Latvia) | Straumite, E., Latvia Univ. of Agriculture, Jelgava (Latvia) | Cinkmanis, I., Latvia Univ. of Agriculture, Jelgava (Latvia)
Growing interest of consumers in healthy eating has provided the development of new range of food. Therefore the task of research was to determine the nutritional value, calculate energy value and investigate the sensory properties of yoghurt samples enriched with flakes from biologically activated hull-less barley grains and malt extract. Results showed that by adding flakes from biologically activated hull-less barley grain and malt extract it was possible to improve the nutritional value of yoghurt, i.e., increased protein, carbohydrate and decreased fat content. The energy value of yoghurt samples enriched with flakes from biologically activated hull-less barley grain and malt extract ranged between 65.96 and 75.72 kcal 100 gE-1, which is significantly lower comparing with mean energy value of commercial yoghurts. The changes of sensory properties were affected by the amount of added malt extract in yoghurt samples. The optimal amount of added malt extract for sensory evaluation in yoghurt samples was determined as 2%. The content of carbohydrate in yoghurt sample enriched with 5% of biologically activated hull-less barley grain and 2% of malt extract was two times lower than commercial yoghurts therefore its energy value was significantly lower. Yoghurt enriched with flakes from biologically activated hull-less barley grain and malt extract could be competitive.
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