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The analytical procedure of thiamine quantification in premixtures and compound feedingstuffs by HPLC method is presented. Thiamine was extracted from feed samples with 0.1M hydrochloric acid at 100°C for 30 min. In the case of compound feedingstuffs, 10% Taka-diastase solution was added to the samples, and then the samples were incubated at 37°C for 17 h. Afterwards, thiamine was oxidised to thiochrom, using 1% alkaline potassium ferricyanide (III). The filtrated solution was analysed by HPLC with isocratic flow of eluent chloroform-methanol 90:10 (v/v). The measurement was done by a fluorescence detector. This method has been applied for the quantification of the total content of thiamine in compound feedingstuffs, as well as added thiamine in the form of hydrochloride or nitrate salt. The limit of the quantification of this method was determined on the level of 1 mg/kg. The coefficient variation of thiamine quantification results in premixţures samples was 3.7%, and in compound feedingstuffs was 5.56%. The Horrat value for premixture samples reached a value of 0.60, whereas in the case of compound feedingstuffs it was 0.63, thus confirming acceptable precision of the procedure. The recovery rate for thiamine added in the form of hydrochloride was 102.3% in premixes and 98.9% in compound feedingstuffs. The recovery rate for thiamine added in the form of nitrate salt to compound feedingstuffs was similar and reached a value equal to 98.7%.
Thiamin (vitamin B1) is an essential molecule for all living organisms. Its major biologically active derivative is thiamin diphosphate, which serves as a cofactor for several enzymes involved in carbohydrate and amino acid metabolism. Important new functions for thiamin and its phosphate esters have recently been suggested, e.g. in gene expression regulation by influencing mRNA structure, in DNA repair after UV illumination, and in the protection of some organelles against reactive oxygen species. Unlike higher animals, which rely on nutritional thiamin intake, yeasts can synthesize thiamin de novo. The biosynthesis pathways include the separate synthesis of two precursors, 4-amino-5-hydroxymethyl-2-methylpyrimidine diphosphate and 5-(2-hydroxyethyl)-4-methylthiazole phosphate, which are then condensed into thiamin monophosphate. Additionally, yeasts evolved salvage mechanisms to utilize thiamin and its dephosphorylated late precursors, 4-amino-5-hydroxymethyl-2-methylpyrimidine and 5-(2-hydroxyethyl)-4-methylthiazole, from the environment. The current state of knowledge on the discrete steps of thiamin biosynthesis in yeasts is far from satisfactory; many intermediates are postulated only by analogy to the much better understood biosynthesis process in bacteria. On the other hand, the genetic mechanisms regulating thiamin biosynthesis in yeasts are currently under extensive exploration. Only recently, the structures of some of the yeast enzymes involved in thiamin biosynthesis, such as thiamin diphosphokinase and thiazole synthase, were determined at the atomic resolution, and mechanistic proposals for the catalysis of particular biosynthetic steps started to emerge.
There is relatively little information concerning the bioavailability of thiamine from food products; nevertheless available data on thiamine show that this vitamin is a significant factor that plays an important role in their nutritional status. The bioavailability of thiamine depends on several factors of which food and diet composition appears to play a paramount importance.
In the study of the concentration of thiamine in the plasma, liver, urine and faeces as indices of its utilisation we found that cellulose enhances the bioavailability of this vitamin in vivo; however, pectin has an opposite effect, that is, it lowers its bioavailability.
The effects of thiamine (vitamin B1) on the level of spontaneous or radia­tion-induced genetic changes in human lymphocytes in vitro were studied. Cul­tured lymphocytes were exposed to increasing concentrations of thiamine (0-500 Ug/ml) and irradiated with X-rays. The DNA damage was estimated as the frequency of micronuclei and apoptotic or necrotic morphological changes in fixed cells. The results show that thiamine alone did not induce genetic changes. A significant decrease in the fraction of apoptotic and necrotic cells was observed in lymphocytes irradiated in the presence of vitamin B1 at concentrations between 1-100 ug/ml compared to those irradiated in the absence of thiamine. Vitamin B1 at 1 and 10 Ug/ml decreased also the extent of radiation-induced formation of micronuclei. Vita­min B1 had no effect on radiation-induced cytotoxicity as measured by nuclear divi­sion index. The results indicate that vitamin B1 protects human cells from radia­tion-induced genetic changes.
In the research the effect of thermal processing in a convection oven on dishes quality was evaluated. The quantitative and qualitative changes of some nutritive values and sensory indices were estimated in comparison with conventional methods of thermal processing. In the study raw materials and dishes of vegetable (sauerkraut and potatoes) and animal origin (cooked and roasted meat, cooked and fried minced meat balls) were investigated. The content of ascorbic acid and neutral detergent fiber (NDF) were used as the nutrition value indices of investigated vegetable dishes. Thiamine and collagen changes in meat dishes and retention of iodine in the products (meat balls) with addition of iodized salt were analyzed. All prepared dishes were sensory evaluated with the triangle test.
Celem pracy było ustalenie stopnia oddziaływania dodatku soli jodowanej jodkiem potasu na zmiany ilościowe i jakościowe tiaminy, w procesie gotowania i późniejszego przechowywania wybranych potraw mięsnych. W badaniach uwzględniono mięso o zachowanej strukturze histologicznej - tzw. „sztukę mięsa”, mięso rozdrobnione (pulpety) oraz mięsny farsz pierogowy. Przygotowane potrawy przechowywano w warunkach chłodniczych przez 7 dni oraz zamrażalniczych przez 30 dni. Przeprowadzone badania wykazały, że najmniejsze ubytki tiaminy ogólnej stanowiące 53% stwierdzono podczas gotowania mięsa w kawałku w obecności chlorku sodu. Mniejszą podatność na degradację termiczną wykazywała tiamina wolna niż związana. Większe straty tiaminy stwierdzono w mięsie rozdrobnionym niż w litym kawałku mięsa. Wprowadzenie soli jodowanej przyspieszało dynamikę rozpadu tiaminy wolnej i związanej. Przechowywanie badanych potraw w warunkach chłodniczych, jak i zamrażalniczych zwiększało straty zarówno tiaminy wolnej, jak i związanej.
The aim of this research was a study of the influence of calcium pantothenate with thiamine and selected mineral compounds on alcoholic fermentation course of rye mash with the density of 19,5°Blg and 25,1°Blg and the quality of raw spirit obtained. The research was conducted with a sweet rye mash made according to Henze technology. Basing on the research it was stated that the additive of a few mineral compounds as ammonium sulfate, potasium biphosphate, magnesium sulfate to rye mash of 19,5°Blg increase the productivity of ethanol obtaining process from starch. Resides there is an improvement of all biotechnological indexes of fermentation and the level reduction of higher alcohols and esters content in raw spirits. However an additive of calcium pantothenate with thiamine to the mash of the same density causes the quality improvement of the obtained raw spirit by reduction of the formed aldehydes and fusel oils without essential influence on fermentation process. At higher density of rye mash up to 25,1°Blg the best biotechnological indexes of fermentation process and the highest reduction of the formed impurities of raw spirit were reached by tests with additive of calcium pantothenate with thiamine.
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