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Career-related possible selves of rural adolescents
2013
Pavulens, J., Latvia Univ. of Agriculture, Jelgava (Latvia)
The first independent career related decisions are made during the ninth grade of the elementary school when the further educational institution is selected. The concept of possible selves can be used in career education to help students increase self-awareness, explore and generate options, and formulate plans to achieve future goals. The aim of the article is to examine rural adolescents’ ability to generate career-related possible selves and plausible strategies to attain these possible selves. On the basis of the Possible Selves Theory, the open-ended measure was developed by the author. The pilot research was carried out in Latvia in January 2013. Forty six nine-graders from two rural elementary schools and two rural secondary schools participated in the research. Next year and adult possible selves generated by rural adolescents include such domains as education, employment, leisure activities, physical and personal development, as well as interpersonal relationships and lifestyle. The most important ones are domains of education and employment. Statistically significant differences of the results among the gender subgroups are not found in the research, statistically significant differences exist between the possible selves and their attaining strategies generated by rural secondary school students and rural elementary school students.
显示更多 [+] 显示较少 [-]Production of bioethanol from starch based agriculture raw material
2013
Jansone, I., Latvia Univ. of Agriculture, Jelgava (Latvia);State Stende Cereals Breeding Inst., „Dižzemes”, Dižstende, Lībagi parish, Talsi municipality (Latvia) | Gaile, Z., Latvia Univ. of Agriculture, Jelgava (Latvia)
Bioethanol can be used for food production and to partially replace fossil fuel. Bioethanol is mainly produced from renewable biomass that contains sugars, starch or lignocellulose. The main raw materials for production of bioethanol are cereals, maize (Zea mays), sugarbeets (Beta vulgaris sacccharifera) and other plant species. During the trial that took place in State Stende Cereals Breeding Institute during a three year period (from 2009/2010 to 2011/2012) we examined the suitability of grain from winter wheat (Triticum aestivum L.), triticale (×Triticosecale Wittm) and rye (Secale cereale L.) for the production of bioethanol. Three varieties of each species were used in the trial. During the trial period the grain yield, the ethanol outcome (L tE-1) and the ethanol yield (L haE-1) were determined. It was established that during three years wheat and triticale provided the highest starch content (more than 700 g kgE-1) of the grain as well as the highest ethanol outcome (L tE-1). These species provided both high grain yield (more than 9 t haE-1 on average) and the highest ethanol yield (3300 – 4665 L haE-1). The choice of variety was also important as both the grain starch content and the grain yield depend on the genotype of the variety.
显示更多 [+] 显示较少 [-]Goat milk composition variability after kid weaning
2013
Piliena, k., Latvia Univ. of Agriculture, Jelgava (Latvia) | Jonkus, D., Latvia Univ. of Agriculture, Jelgava (Latvia)
The aim of the research was to evaluate the variability of milk yield and composition for goats with different kid suckling periods. The research was carried out in 2011 and 2012 on a farm where goats of Latvian breed were reared. In both years goats kidded in February and March. Each group included 10 animals. In the first group the kids were weaned on the first day of kidding (A1), in the second – on the 30th day (A30) but in the third – on the 60th day (A60) after kidding. The amount of the milk yield was measured in five successive days after the kid weaning. Milk samples were analysed in an accredited milk laboratory. The highest milk yield was obtained from the goats when kids were weaned immediately after the birth, and samples were taken starting with the 6th day of lactation (2.10 + 0.05 kg), but the lowest from the goats with suckling period of 60 days – 1.68 ± 0.03 kg. The average milk fat and protein content of the goats from the group A1 (53.6 ± 0.92 and 41.6 ± 0.66 g kgE-1), was significantly higher than from the groups A30 and A60 (p is less than 0.05). The average variability of milk yield proved to be from 4.9% in the group A1 to 10.5% in the group A30. The lowest fat content variability was observed for goats of the group A1 in both years – 8.9% and 10.7%, but the highest 20.5% in the group A60 in the first year. The highest variability of milk protein content was observed in the group A30 – 14.8%.
显示更多 [+] 显示较少 [-]Estimation of genetic parameters for growth traits of sheep population in Latvia
2013
Puste, A., Latvia Univ. of Agriculture, Jelgava (Latvia) | Kairisa, D., Latvia Univ. of Agriculture, Jelgava (Latvia) | Sarma, R., Latvia Univ. of Agriculture, Jelgava (Latvia)
The aim of the present study was to estimate variance and covariance components and genetic parameters for birth, weaning and yearling weights. The data were collected from lambs who born in period from 2007 to 2010 years and located in 58 pure-bred sheep herds in Latvia. Records of 11310 lambs from 160 rams and 4180 ewes for birth and weaning weight and on 3194 lambs from 134 rams and 2058 ewes for yearling weight were used in this study. The total number of individual pedigree was 18932. The fixed effects in the model were sex and type of birth, birth year and month and age of dam, because all growth traits were significantly affected by these fixed effects (p is less than 0.01, p is less than 0.05). Genetic parameters for growth weights were estimated by Restricted Maximum Likelihood (REML) procedure fitting three animal models including various combinations of maternal and herd effects. Based on the most appropriate fitted model which included additive genetic, maternal additive genetic and herd effect, direct heritability’s were estimated to be 0.26 ± 0.01, 0.29 ± 0.63, 0.29 ± 2.63, but maternal heritability’s 0.14 ± 0.00, 0.04 ± 0.19, 0.04 ± 0.94, respectively for birth, weaning and yearling weights. The results showed maternal and strong herd influence in this study, therefore inclusion of maternal and herd effects into the model for growth traits is necessary.
显示更多 [+] 显示较少 [-]Analysis of conformation of forelegs and hind legs of Latvian warmblood carriage type mares
2013
Orbidane, L., Latvia Univ. of Agriculture, Jelgava (Latvia) | Jonkus, D., Latvia Univ. of Agriculture, Jelgava (Latvia)
The aim of the study was to analyze an occurrence of forelimb and hind limb conformation traits in the population of the Latvian warmblood carriage type broodmares accepted as appropriate for the breed’s genetic resources and an occurrence of these traits depending on the origin. The conformation traits of limbs were analyzed in the population of the Latvian warmblood carriage type’s broodmares accepted as appropriate for the genetic resources from 2004 to 2012 and registered in the Stud Book, the group consisted of 301 mare of which 104 mares had a description of the conformation in Stud Book or database. Based on common female ancestors the broodmares were divided in families, recognized as important for improving the breed, and other related groups. The quality of limbs in the population of broodmares included in genetic resources was compared to the quality of limbs in the population of their female ancestors. Good limb conformation was characteristic to 28.8% of broodmares. The most common conformation faults were toeing-in of forelegs and base-narrow position of forelimbs and hind limbs. The occurrence of conformation faults as sloping pasterns of forelegs and hind legs and sickle-hocks was rarer in nowadays population than in population of female ancestors. The occurrence of toeing-in of forelegs increased from 9.7% to 19.2%, a significant difference between contemporary population and ancestors was found (p is less than 0.05). A significant difference in limb quality between groups with different origins was not found.
显示更多 [+] 显示较少 [-]Sensory evaluation of new bean spreads for vegetarians
2013
Kirse, A., Latvia Univ. of Agriculture, Jelgava (Latvia) | Karklina, D., Latvia Univ. of Agriculture, Jelgava (Latvia) | Strautniece, E.V., Latvia Univ. of Agriculture, Jelgava (Latvia)
Vegetarianism is a growing trend in Latvia but there is a lack of spread-like products for vegetarians. There are about 10 plant protein spreads commercially available in Latvia that differs very much in nutritional value and ingredients. Common beans (Phaseolus vulgaris L.) which are popular among Latvian consumers and rich in important macro- and micronutrients could be a great source of protein for vegetarians in spread-like products, however, are not represented in foreign or Latvian food company products yet. The aim of this research is to develop new vegetarian spreads using commercially available beans in Latvia and to subject the newly developed bean spreads to sensory evaluation. Four bean spreads were developed using white beans: classic, with basil, with curry, and with sun-dried tomatoes. Samples of bean spreads were packed in 200 g polypropylene (PP) containers and after 12 h storage in a refrigerator (3 ± 1 °C) subjected to sensory evaluation. Sensory evaluation was carried out in 3 different groups of panellists using hedonic scale and line scale. The hedonic evaluation showed that bean spread with sun-dried tomatoes has the highest overall preference compared to other bean spreads (p is less than 0.05). Significant differences among four bean spread samples in the intensity of their sensory properties – acidity, bean flavour, saltiness, and colour – were found (p is less than 0.05). Based on sensory evaluation data further research should be continued with classic bean spread and bean spread with sun-dried tomatoes.
显示更多 [+] 显示较少 [-]Different temperature treatment effects on the changes of the functional properties of beans (phaseolus)
2013
Strauta, L., Latvia Univ. of Agriculture, Jelgava (Latvia) | Muizniece-Brasava, S., Latvia Univ. of Agriculture, Jelgava (Latvia)
The experiment was carried out in the Latvia University of Agriculture. The objectives of this research were to study changes of bean (Phaseolus) protein fractions occurring under the thermal treatment conditions and determine the critical temperature for Maillard reactions in beans. In these reactions lignified protein is made from amino acids and sugars, and it decreases the nutrition value of the food. If lignified protein exceeds 50% of crude protein content in food, then food is considered unsuitable for daily diet. In this experiment beans were milled and then heated at 50 ± 3 °C, 75 ± 3 °C, 100 ± 3 °C, 125 ± 3 °C and 150 ± 3 °C temperature in the drying oven for 20 h. As a control sample non heated beans were used, and they all were kept in a plastic jar at room temperature (20 ± 1 °C). Dry matter, crude protein, starch, sugar and lignified protein content were determined in heated beans and control samples. No significant changes of crude protein content were observed due to thermal treatment. It was from 24.3 ± 0.3 g 100 g-1 of dry matter. Similarly, no significant changes were observed in starch content, as it stayed averagely 47.1 ± 0.2 g 100 g-1 of dry matter. Medium high correlation was observed (0.64) between lignified protein content and sugar content for in different temperature treated beans. Lignified protein showed exponential growth if the samples were heated at a temperature of 100 ± 3 °C and higher, giving exponential change.
显示更多 [+] 显示较少 [-]Effect of hydrogen peroxide on the quality parameters of shredded carrots
2013
Augspole, I., Latvia Univ. of Agriculture, Jelgava (Latvia) | Rakcejeva, T., Latvia Univ. of Agriculture, Jelgava (Latvia)
The main purpose of the present experiments was to investigate the effect of various hydrogen peroxide (H2O2) concentrations and for various lengths of treatment on the total carotenoid, β–carotene content, colour intensity and microbiological safety on the fresh shredded carrots. Shredded carrots were dipped in 0.5, 1.0 and 1.5% H2 O2 water solution for 30 ± 1s, 60 ± 1s and 90 ± 1s. Negative effect of H2 O2 on β–carotene content and colour parameters of analyzed shredded carrots samples was not detected. In carrots treated with H2 O2 (p = 0.008) for 60 – 90s the total content of carotenoids significantly decreased during treatment compared to untreated carrot samples. There was significant difference (p is less than 0.05) observed between treated and non–treated shredded carrot samples on the total bacteria count. It was possible to reduce significantly (p is less than 0.05) the content of yeasts and mould up to 99.99% by shredded carrots treatment with 1.5% hydrogen peroxide water solution for 30 ± 1s. In the non–processed carrots E.coli was detected; however, it was possible to destroy E.coli by treating carrots with 0.5% H2 O2 water solution for 30 ± 1s. Considering all experimentally obtained results, we have concluded that fresh shredded carrots could be treated in water with the addition of hydrogen peroxide 1.5% for 30 ± 1s to maintain quality.
显示更多 [+] 显示较少 [-]Total polyphenols, flavonoids and antiradical activity of vegetables dried in convective and microwave-vacuum driers
2013
Priecina, L., Latvia Univ. of Agriculture, Jelgava (Latvia) | Karklina, D., Latvia Univ. of Agriculture, Jelgava (Latvia)
Fruits and vegetables are a major source of antioxidants. The aim of current research was to study and compare the antiradical activity, the total polyphenol content (TPC) and the total flavonoid content (TFC) in dried carrots (Daucus carota), pumpkins (Cucurbita maxima), leeks (Allium ampeloprasum var. porrum) and black radish (Raphamussativus) using a traditional convective drier and a microwave-vacuum drier. For each vegetable steaming as pre-treatment was used. Vegetables were harvested in Latvia in 2012, gathered when ripe and then dried. Analyses were made in Latvia University of Agriculture, Faculty of Food Technology laboratories. The total polyphenol content was determined by the Folin- Ciocalteu method and the total flavonoid content - using spectrophotometric method. The antiradical activity was analyzed by the 2,2-diphenyl-1-picrilhydrazyl (DPPH) assay. The results of experiments demonstrate that the total amount of polyphenols ranged from 98.97 to 623.70 mg gallic acid equivalent (GAE) 100 gE-1 in dry weight and the total amount of flavonoids ranged from 40.32 to 100.23 mg catechin equivalent (CE) 100 gE-1 in dry weight. The value of DPPH antiradical activity for vegetable samples ranged from 6.10 to 45.14 percents.
显示更多 [+] 显示较少 [-]The influence of selenium and copper on microbiological indicators of rye malt
2013
Antonenko, K., Latvia Univ. of Agriculture, Jelgava (Latvia) | Kozlinskis, E., Latvia Univ. of Agriculture, Jelgava (Latvia)
Malt is a natural food product produced by germinating cereal grains. Safety of cereal grains and cereal products is a very important area. Experiments were carried out at the Faculty of Food Technology of the Latvia University of Agriculture. The research object was rye malt. The purpose of the research was to investigate and compare the influence of copper and selenium on microbiological indicators of rye malt. Rye grains of 96% viability were soaked and germinated at temperature +6 ± 2 °C for 4 days, using copper(II) sulphate pentahydrate CuS04*5H2 O solutions (Cu concentration 10 mg LE-1, 50 mg LE-1, 100 mg LE-1) and for 3 days using sodium selenate Na2 SeO4 solutions (Se concentration 3 mg LE-1, 5 mg LE-1, 10 mg LE-1) then the soaked grains dried in the oven for 24 hours. The total plate count and yeast colony forming units were determined in rye malt samples. The obtained results showed that the increasing of copper and selenium concentration in solution significantly changes microflora of rye malt comparing with the control sample.
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