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Changes in poultry meat microstructure during chilled storage
2008
Ramane, K., Latvia Univ. of Agriculture, Jelgava (Latvia) | Klava, D., Latvia Univ. of Agriculture, Jelgava (Latvia) | Galoburda, R., Latvia Univ. of Agriculture, Jelgava (Latvia)
Researchers have found that morphology of muscle structure (original or after processing) is closely related to meat tenderness, which is very important attribute for consumer. The aim of the study was to evaluate changes in microstructure of poultry meat during the chilled storage. In the study, the cross-cut microstructure of parents stock hen and broiler muscles were analyzed during the storage at + 1 +- 0.5 °C temperature. The changes were determined for the following muscles: musculus pectoralis and pars praeacetabularis musculus iliotibialis lateralis in seven hours after slaughter and on the 7th day of storage. Parents’ stock (PS) hens were slaughtered on 61st week, but broilers at the age of 42 days (on the 6th week). The decrease in area of muscle fibres of hens and broilers' musculus pectoralis was found in both types of meat when comparing the sample on 7th hour and 7th day, but the smaller decrease was observed in broilers meat. Comparing muscle fibre area of broiler and hen pars praeacetabularis musculus iliotibialis lateralis [musculus biceps femoris] in hen meat it was reduced in higher proportion, but the distance between the fibres was increased reaching similar values for both sample types.
Afficher plus [+] Moins [-]Effect of storage time, temperature and solvent on the stability of sterigmatocystin standard solutions
2008
Versilovskis, A., Latvia Univ. of Agriculture, Jelgava (Latvia) | Mikelsone, V., Latvia Univ. of Agriculture, Jelgava (Latvia)
The influence of solvent, storage time and temperature on the stability of the mycotoxin sterigmatocystin (STC) was investigated. STC calibrants (1.0 μg mlE-1) in acetonitrile, methanol and mixture of acetonitrile and methanol (50:50, volume/volume) were stored in dark glass bottles at (– 25), 4 and 25 °C for up to 8 weeks. Samples were analysed by high performance liquid chromatography (HPLC) with ultraviolet (UV) detection. Obtained results indicate that more suitable solvents for storage of STC standard solutions at (–25 °C) are acetonitrile and mixture of acetonitrile and methanol (50:50, v/v), but not longer than for one week; for storage at 4 °C more suitable is mix of acetonitrile and methanol, but not longer than for one week.
Afficher plus [+] Moins [-]Nutritional changes in several potato varieties during heat treatment processes
2008
Murniece, I., Latvia Univ. of Agriculture, Jelgava (Latvia) | Karklina, D., Latvia Univ. of Agriculture, Jelgava (Latvia) | Galoburda, R., Latvia Univ. of Agriculture, Jelgava (Latvia)
Processing and cooking methods can greatly affect the nutritional value of fruits and vegetables including potatoes. In human nutrition potatoes before consumption are always prepared by several cooking methods and are one of the central components of warm meals. During treatment processes considerable changes in nutritional composition and nutritional quality of the product are induced. Hence the aim of the study was to determine the amount of basic nutrients (carbohydrate, fat and protein) as well as essential amino acids in five Latvian potato varieties prepared by the following heat treatment methods: baking in oven, shallow frying and deep fat frying and to compare the obtained results with recommended daily intake (RDI). Achieved results show significant differences in total carbohydrate amount within potato varieties (p=0.007) while within the type of heat treatments were no significance (p=0.065). Changes in fat content between heat treatment processes were considerable (p=0.000) whereas significance were discovered between control – pan fried, control – deep fat fried, baked in oven – pan fried, baked in oven – deep fat fried as well as pan fried – deep fat fried samples while no significance found among potato varieties (p=0.391). In protein amount neither within potato varieties nor between heat treatment processes significance was discovered, but the amount of essential amino acids significantly differs per each potato variety and type of heat treatment processes. Results on RDI per each nutrient group (fat, carbohydrates and protein) show significance on % RDI per each basic nutrient.
Afficher plus [+] Moins [-]Evaluation of texture parameters of vacuum and modified atmosphere packed fresh carp (Cyprinus carpio L.)
2008
Kamolina, E., Latvia Univ. of Agriculture, Jelgava (Latvia) | Dukalska, L., Latvia Univ. of Agriculture, Jelgava (Latvia)
Investigations of textural parameters of vacuum, protective gas atmosphere (MAP), and at air ambiance packed fresh carp (Cyprinus carpio L.) farmed in Latvia were carried out. The samples of carp were stored at two different temperatures (0 +- 0.5 and +4 +- 0.5 ºC) applying three different types of packaging – vacuum, MAP, and wrapping at air ambiance. Gas mixture used for MAP consisted of 40% CO2 and 60% N2. Samples were analyzed before packaging (day 0) and after 2, 4, 6, 8, 11 and 14 storage days. Textural parameters – hardness and shear force were evaluated by texture analyzer TA.XT.plus (Stable Micro System Ltd.). Two instrumental methods were applied for evaluation of textural properties. One method was based on compression test, using spherical probe, 25.4 mm in diameter (type P/1S), and measuring the hardness of the fillet and other method was based on cutting the fillet with a blade (type HDP/BSK) and measuring the shear force. The instrumental hardness and shear force of fresh carp fillets decreased during storage time. Texture variables significantly correlate with storage time, respectively, r = -0.723 and r = -0.748, the hardness and shear force. The storage time, temperature and packaging type with probability of 95 % substantially influence the textural parameters of carp fillets (P is less than 0.05).
Afficher plus [+] Moins [-]Influence of pig complex activities on the Šušvė River pollution with nitrogen compounds
2008
Strusevičius, Z., Lithuanian Univ. of Agriculture, Kaunas (Lithuania). Water Management Inst. | Struseviciene, S.M., Lithuanian Univ. of Agriculture, Kaunas (Lithuania). Water Management Inst.
The research was made in the Šušvė river basin fertilized with organic fertilizer in the vicinity of a pig complex 'Litpirma' Ltd (25.0 thousand fattening pigs per year), Šiaulėnai local administration, Radviliškis district, in 2001-2006. This article presents total nitrogen concentrations and its amounts leaching from the complex to the basin, in the field drainage water and the Šušvė River (at a distance of 11.6 km from the pig complex). In the investigated Šušvė section, biologically treated wastewater from Šiaulėnai Township and the areas fertilized with organic fertilizers comes into the river. In total, 11.8 t of nitrogen come into the river, of which 4% (0.49 t) come from the township's wastewater, and the rest major part (96% or 11.3 t) is the drainage water coming from fertilized agricultural fields. The dynamics of nitrogen concentrations both in the river and in the drainage outlet is of a seasonal nature: in winter (January – March) concentrations were higher, and in warm season (April – November) – lower. The Šušvė pollution by total nitrogen, both above and below the pig complex activities range, almost all the research period was exceeding the limit (2 mg lE-1). Due to the pig complex activities and intensive agriculture, the runoff of nitrogen pollutants increases from 14.9 to 29.3% in the Šušvė River. This proves that the processes of spontaneous purification are not intensive enough to neutralize completely the pollution from such size pig complex in this particular section of the river.
Afficher plus [+] Moins [-]Visible and infrared absorption spectra of covering materials for solar collectors
2008
Pelece, I., Latvia Univ. of Agriculture, Jelgava (Latvia)
Use of solar energy increases every year. In Latvia, solar energy is used mainly by solar collectors. The main part of the solar collector is the absorber, but not less important is the covering material which protects the absorber from the cooling impact of the wind. This cover must be transparent for solar radiation, but opaque for thermal radiation of the absorber, which is at greater wavelengths. Therefore it is important to measure absorption spectra of possible covering materials at visible and infrared wavelength ranges. Absorption spectra have been measured for several materials: glass, polythene, Plexiglas, and cells Plexiglas. Absorption spectra for all these materials are measured in three ranges: ultraviolet – visible (UV – VIS): 250 – 1000 nm; near infrared (NIR): 700 – 110 nm; infrared (IR): 1200 – 8000 nm. UV-VIS spectra with the ‘Ocean Optics’ device HR-4000 have been measured, but NIR and IR – with ‘Bruker’ Furje spectrometer EQUINOX 55. Evaluation of absorption spectra showed that the most suitable material (from the considered) for covering of solar collectors is Plexiglas.
Afficher plus [+] Moins [-]Inflammatory factors and apoptosis in the cow's endometrium in postparturition period
2008
Sematovica, I., Latvia Univ. of Agriculture, Jelgava (Latvia) | Jemeljanovs, A., Latvia Univ. of Agriculture, Jelgava (Latvia) | Pilmane, M., Riga Stradins Univ. (Latvia)
Nine multiparous cows were biopsied twice – in the first and fifth week after parturition in winter 2004/2005 on the Research and Study farm Vecauce of Latvia University of Agriculture. The aim of the research was to reveal distribution of inflammatory factors and apoptosis in the cow’s endometrium in post parturition period. Haematoxylin and eosin were used for routine staining of each sample. Tumor necrosis factor α (TNFα, w.d. 1:100, Abcam, England), and interleukin 10 (IL10, w.d. 1:400, Abcam, England) were detected immunohistochemically (IMH), and TUNEL method was used for detection of apoptosis. Distribution of these factors and substances was determined semiquantitatively by counting positive structures in visual fields. A significant increase in the total amount of inflammatory cells, as well as in the amount of the TNFα and apoptotic cells in endometrium between the first and fifth week after parturition (p is less than 0.01) was observed. A significant positive correlation (r=0.41; p is less than 0.01) between infiltration of endometrium with neutrophils and with macrophages was detected in the first week after parturition. A mild positive correlation (r=0.52; p is less than 0.01) between neutrophils and lymphocytes, as well as between lymphocytes and macrophages (r=0.35; p is less than 0.01) was found four weeks after parturition. A mild positive correlation (p is less than 0.05) was observed between amount of inflammatory cells and TNFα (r=0.52), and number of apoptotic cells and TNFα (r=0.58). The research suggests that inflammatory factors and apoptosis intensively act during the process of involution in the cows’ endometrium from the first up to the fifth week after parturition. Intensity, amount and activity of these components show individual variations in each case.
Afficher plus [+] Moins [-]The possibility of application of iodized salt in pickle manufacturing
2008
Ansone, I., Latvia Univ. of Agriculture, Jelgava (Latvia) | Blija, A., Latvia Univ. of Agriculture, Jelgava (Latvia)
Iodine is a mineral that is added to the table salt and found in a variety of foods. It is important for good health and, fortunately, our bodies require it in minute quantities. Iodine is part of a hormone, thyroxin, which is responsible for maintaining a person’s metabolic rate. Iodine is the basic constituent part of the hormone of the thyreoid gland. On the whole, the amount of T3 and T4 correlates with the number of the iodine atoms. Therefore, without iodine the thyreoid gland cannot synthesize hormones and, therefore, cannot function. The role of iodine intake in both of these conditions was recognized in the 20th century, and since they are fully preventable through diet, public health advocates hope to entirely eliminate them at some point. Many things are natural sources of iodine. Saltwater fish and sea vegetables, for example, both contain abundant amounts of iodine. The material can also be found in plants grown on soil which is rich in sea materials, and in animals grazed on such soils. In some regions of Latvia, however, access to iodine is limited, and conditions like goiter, is realistic of iodine deficiency situations. In Latvia, some fear exists for manufacturers of food who use iodized salt. They are afraid that it will collide with changes of colour or taste of their products and will infringe on interests of the consumer. The main question for such problems is: is it a myth or the truth? In Latvia, starting using iodine salt in manufacturing, the most important question is: ‘What quantity of iodine remains after the technological processing?‘
Afficher plus [+] Moins [-]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.
Afficher plus [+] Moins [-]The structure of rural economy in Zemgale intra-regions
2008
Liscova, A., Latvia Univ. of Agriculture, Jelgava (Latvia)
Zemgale planning region divides into two intra-regions (Zemgale 1 and Zemgale 2) by natural, soil and other agricultural resources. Each intra-region has different size of farms. The aim of the research was to find the structure of rural economy in different size farms or rural enterprises of Zemgale 1 and Zemgale 2 intra-regions. The research showed that very small farms dominate grow-plant sectors production. Medium size farms and enterprises have solid high proportion of grow-plant sector production in total production value. This proportion is even higher in biggest agricultural enterprises and companies (100 is less than or equal 250 ESU). In general author has stated that in Zemgale 1, which is the biggest agricultural production territory in Latvia, grow-plant production sectors dominate.
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