خيارات البحث
النتائج 1 - 10 من 26
Diversity of non-starter lactic acid bacteria in Latvian semi-hard cheeses
2009
Mikelsone, A., Latvia Univ. of Agriculture, Jelgava (Latvia) | Ciprovica, I., Latvia Univ. of Agriculture, Jelgava (Latvia)
The most non-starter lactic acid bacteria (NSLAB) isolated from semi-hard cheeses are heterofermentative and handled as one of the reasons of cheese off-flavours and yield defect but at the same time majority of researches argued positive effect of NSLAB on cheese flavour formation and diversification due to rendered compounds of chemical reactions. The amount of NSLAB in cheese varies from 10 at the beginning of ripening to 105 cfu mlE-1 within 6-8 weeks. The aims of this paper were to establish diversity of NSLAB in commercial samples of Krievijas and Holandes cheeses, and to evaluate the effect of ripening temperatures on NSLAB in the trials of Krievijas cheese. A total of 12 commercial cheese samples from seven different Latvian manufacturers and trials from one cheese manufacturer were examined. The trials were ripened for 60 days at different temperatures - 6 deg C and 12 deg C. Serial dilutions of each cheese sample (1:1000 and 1:10 000) in saline were made. NSLAB were cultivated using MRS media. Strain identification was performed by the API 50 CHL system (BioMerieux, Marey l'Etoile, France). In commercial samples of Krievijas cheese dominance of L. curvatus was observed, simultaneously L.plantarum and L.paracasei subsp. paracasei were isolated. Whereas in Holandes cheese samples dominance of L.paracasei subsp. paracasei was noted and L.plantarum, L.curvatus, L.rhamnosus and L.acidophilus were isolated. In the trials ripened at different temperatures prevalence of L.curvatus was noted. Concentration of Lactobacillus spp. varied from 104 cfu mlE-1 on the first day of ripening and reached the highest concentration (106 cfu mlE-1) after 6 weeks of ripening.
اظهر المزيد [+] اقل [-]Changes in quality of parents stock hens meat during chilled storage
2009
Ramane, K., Latvia Univ. of Agriculture, Jelgava (Latvia) | Galoburda, R., Latvia Univ. of Agriculture, Jelgava (Latvia)
The aim was to study changes of chemical composition (fat content, protein content), pH and colour of poultry meat during chilled storage. Various criteria are used for evaluation of bird and carcass quality, while the combination of several indices determines the quality of poultry meat, which has an important role in the following meat processing and quality of end product. Chilled poultry meat is offered in retail and it is used in processing plants for various meat products production. Chemical composition (fat content, protein content), pH and colour are important quality determinants. Hens' meat is cheaper compared to broiler meat; therefore its use in processing is profitable. Parents stock hens of the cross Ross 308 were used for the study. Parent stock hens were fed compound feed. After chilling a hen fillet [musculus pectoralis], hen thighs [musculus biceps] and hen drumsticks [musculus gastrocnemius; musculus fibularis longus] were separated from carcasses. The obtained products were refrigerated at temperature +1+-0.5 deg C. The analyses were performed 1 day after slaughter and on the 5th day of storage. The following parameters were analysed: pH value (3510pH Meter - JENWAY); total protein content (LVS ISO 937:1978); fat content (LVS ISO 1443:1973); colour changes (Color Tec-PCM; software ColorSoft QCW for colour data analysis). The analysed parameters significantly differ in 'white' and 'red' poultry meat, and in various cuts of 'red' meat.
اظهر المزيد [+] اقل [-]Effects of growing location and variety on free tryptophan and mineral nutrient content in wheat
2009
Lundegaardh, B., Swedish Univ. of Agricultural Sciences, Upsala (Sweden). Centre for Sustainable Agriculture | Jastrebova, J., Swedish Univ. of Agricultural Sciences, Upsala (Sweden). Dept. of Food Science | Zhokhov, S., Swedish University of Agricultural Sciences, Upsala (Sweden). Dept. of Chemistry | Maartensson, A., Swedish Univ. of Agricultural Sciences, Upsala (Sweden). Dept. of Soil and Environment | Oeborn, I., Swedish Univ. of Agricultural Sciences, Upsala (Sweden). Dept. of Plant Production Ecology
Tryptophan (Trp) is an essential amino acid for mammals since they cannot synthesise it. Wheat (Triticum aestivum L.) is a major source of dietary Trp, and wheat high in Trp would thus be very beneficial. This study investigated the impact of location and wheat variety on the content of free Trp and mineral nutrients in wheat grain. Four wheat cultivars from national variety tests on wheat with varying protein contents were selected from seven different locations of Sweden representing different climatic zones and soil contents of trace elements. Grain was analysed for Trp content using reversed phase HPLC. Mineral nutrients were analysed using inductively coupled plasma emission spectrometry. Wheat yield and grain content of nutrients and Trp differed significantly between sites. High N content in grain was correlated with a high content of Cu, Fe and S, and also Ca and Mg. However, it was correlated with a low content of K and Na. Trp content was positively correlated with Na and Zn content and negatively correlated with K/Na and K/(Na+Zn) ratio. The varieties differed in Trp content and the two ratios, but there were no significant differences in yields between the varieties at any location. The results indicated salt stress induction of Trp synthesis, which may protect wheat against salt stress and yield losses.
اظهر المزيد [+] اقل [-][Factors that influence the starch content in winter rye]
2009
Poisa, L., Latvia Univ. of Agriculture, Jelgava (Latvia);Agricultural Science Centre of Latgale, Vilani, Rezekne reg. (Latvia)
The EU Directive on the promotion of the use of biofuels or other renewable fuels for transport (CO M 2003/30/EC) states that the proportion of biofuels in 2010 must make 5.75% of non-renewable fuels, but in 2020 - 10%. The only way for Latvia to fulfil the Directive 2003/30/EC is to use winter rye because it is one of the oldest cereals grown in Latvia, and Latvia has a long-lasting experience in growing it. A field trial of winter rye (Secale cereale L.) was arranged in the Agricultural Science Centre of Latgale from 2005 to 2007. The influence of four winter rye varieties and five fertilizer rates on grain yield and starch content was researched for three years. The year (factor A), the varieties (factor B), the fertilizer rates (factor C), and the interaction of factors AB, AC , BC, and ABC significantly influenced the yield of grain and the starch content with 95% probability. It is recommended to use good quality grain with high starch content and low protein content for bioethanol production. The varieties of winter rye 'Kaupo', 'Amilo', and 'Walet' are the most suitable for ethanol production in Latgale region.
اظهر المزيد [+] اقل [-]Baking quality and protein composition of emmer wheat landraces
2008
Konvalina, P., University of South Bohemia, Ceske Budejovice (Czech Republic). Faculty of Agriculture | Moudry, J., University of South Bohemia, Ceske Budejovice (Czech Republic). Faculty of Agriculture | Moudry, J. jr., University of South Bohemia, Ceske Budejovice (Czech Republic). Faculty of Agriculture
Emmer wheat, Triticum dicoccum SCHRANK (SCHUEBL), is an old species of cereal which has been traditionally grown in arid areas. The renewed interest in this variety has its origin in favourable quality parameters of emmer wheat grain and a beneficial effect on human organism. This article deals with a study of quality parameters and storage protein composition of 6 varieties of emmer wheat (which have been chosen from the collection of gene bank at the Research institute of Crop Production in Prague-Ruzyně and in České Budějovice). High crude protein content in grain was proved during the trials. Nevertheless, such a characteristic is not suitable for the classical bakery processing (production of leavened products). The analysed genotypes contain more than 10% of high molecular weight glutenins (HMW glutenins), approximately 70% of low molecular weight glutenins + gliadins (LMW glutenins + gliadins), and almost 20% of residual albumins and globulins. Thanks to high share of albumins and globulins, emmer wheat grain is very valuable raw material for the production of healthy diet. The level of stability of storage proteins composition destines the suitability of emmer wheat for organic and low input farming in Less Favoured Areas.
اظهر المزيد [+] اقل [-]Effect of different plant production methods on yield and quality of winter wheat 'Portal' in 2009
2010
Tein, B., Estonian Univ. of Life Sciences, Tartu (Estonia) | Eremeev, V., Estonian Univ. of Life Sciences, Tartu (Estonia) | Keres, I., Estonian Univ. of Life Sciences, Tartu (Estonia) | Selge, A., Estonian Univ. of Life Sciences, Tartu (Estonia) | Luik, A., Estonian Univ. of Life Sciences, Tartu (Estonia)
The yield and quality (volume weight, 1000 kernel weight, protein content, falling number, gluten content, gluten index, gluten content in dry matter) of winter wheat was studied in variety 'Portal'. The wheat was part of the five-year crop rotation experiment where red clover (Trifolium pratense L.), winter wheat (Triticum aestivum L.), peas (Pisum sativum L.), potato (Solanum tuberosum L.) and barley (Hordeum vulgare L.) were following each other. There were two production variants which followed the crop rotation. In one variant mineral fertilizers and pesticides were used, and the other variant was conversion to organic without any synthetic agrochemicals. In mineral fertilizing variant, on the background of P25 and K95 kg haE-1 the N amount varied from 0 to 150 kg haE-1 and herbicide Mustang (preparation norm 0.5 L haE-1, active substance florasulam, 6.25 g LE-1; 2.4-D, 300 g LE-1), insecticide Fastac 50 (preparation norm 0.2 L haE-1, active substance 50 g LE-1 alphacypermethrin) fungicide Falcon EC 460 (preparation norm 0.4 L haE-1, active substances 167 g tebuconazole, 250 g spiroxamine, 43 g triadimenol) and growth regulator Moddus (preparation norm 0.4 L haE-1, active substance 250 g LE-1 trinexapac-ethyl) were used. In conversion to organic the winter wheat grains which followed the red clovers after effect had higher volume weight, 1000 kernel weight and gluten index compared to the variants where mineral fertilizers were used. The yield, protein content, falling number and gluten content in dry matter increased with increase of the amount of mineral N. The wet gluten content was significantly higher compared to the other variants where the N amount was 50 kg haE-1.
اظهر المزيد [+] اقل [-]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.
اظهر المزيد [+] اقل [-]Evaluation of yield and grain quality of oat cultivars
2013
Brunava, L., Latvia Univ. of Agriculture, Jelgava (Latvia);State Stende Cereals Breeding Inst., „Dižzemes”, Dižstende, Lībagi parish, Talsi municipality (Latvia) | Alsina, I., Latvia Univ. of Agriculture, Jelgava (Latvia)
Oat breeders have improved yielding ability potential of oat (Avena sativa L.) cultivars, but set lower standards for biochemical composition of grain. Nowadays the quality of grain for consumers has become important especially in terms of lipids and β-glucan content. Experiments were carried out at State Stende Cereal Breading Institute in the year 2012 to evaluate the oats yield and grain quality. 15 different cultivars of Stende collection were compared by yield and parameters of productivity (test weight and 1000 kernel weight) as well as biochemical parameters (protein, starch, lipid, β-glucan, content). Biochemical parameters were tested by Infratec Analyser 1241. To obtain an equal research background all cultivars were grown in a plant breeding crop rotation field, with similar growing conditions (sowing-time, fertilizer, plant protection activities), which agree with generally accepted technology of oat cultivation in Latvia. Experiments were done in four replications. Plots were laid randomized. ANOVA procedures were used for data analysis. Yield of experimental cultivars varied between 4.28 ± 0.19 - 5.93 ± 0.22 t haE-1, test weight 46.85 ± 0.99 - 52.75 ± 0.44 kg hLE-1, 1000 kernel weight 33.70 ± 0.24 - 46.34 ± 0.80 g. Significant differences of tested yield parameters among oat cultivars were observed. The highest protein content was observed for local breed cultivars ‘Arta’ and ‘Mara’ 119.5 ± 02.6 and 110.5 ± 1.9 g kgE-1 accordingly. Low starch content, but high β-glucan content is characteristic for all Latvian cultivars.
اظهر المزيد [+] اقل [-]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%.
اظهر المزيد [+] اقل [-]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.
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