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Acid Formation (acid + formation)
Selected AbstractsThe role of taurine in diabetes and the development of diabetic complicationsDIABETES/METABOLISM: RESEARCH AND REVIEWS, Issue 5 2001Svend Høime Hansen Abstract The ubiquitously found ,-amino acid taurine has several physiological functions, e.g. in bile acid formation, as an osmolyte by cell volume regulation, in the heart, in the retina, in the formation of N -chlorotaurine by reaction with hypochlorous acid in leucocytes, and possibly for intracellular scavenging of carbonyl groups. Some animals, such as the cat and the C57BL/6 mouse, have disturbances in taurine homeostasis. The C57BL/6 mouse strain is widely used in diabetic and atherosclerotic animal models. In diabetes, the high extracellular levels of glucose disturb the cellular osmoregulation and sorbitol is formed intracellularly due to the intracellular polyol pathway, which is suspected to be one of the key processes in the development of diabetic late complications and associated cellular dysfunctions. Intracellular accumulation of sorbitol is most likely to cause depletion of other intracellular compounds including osmolytes such as myo -inositol and taurine. When considering the clinical complications in diabetes, several links can be established between altered taurine metabolism and the development of cellular dysfunctions in diabetes which cause the clinical complications observed in diabetes, e.g. retinopathy, neuropathy, nephropathy, cardiomyopathy, platelet aggregation, endothelial dysfunction and atherosclerosis. Possible therapeutic perspectives could be a supplementation with taurine and other osmolytes and low-molecular compounds, perhaps in a combinational therapy with aldose reductase inhibitors. Copyright © 2001 John Wiley & Sons, Ltd. [source] Effects of hydrogenation parameters on trans isomer formation, selectivity and melting properties of fatEUROPEAN JOURNAL OF LIPID SCIENCE AND TECHNOLOGY, Issue 3 2008Anar Musavi Abstract Effects of hydrogenation conditions (temperature, hydrogen pressure, stirring rate) on trans fatty acid formation, selectivity and melting behavior of fat were investigated. To this aim, soybean oil was hydrogenated under various conditions and fatty acid composition, trans isomer formation, slip melting point (SMP), solid fat content (SFC) and iodine number (IV) of the samples withdrawn at certain intervals of the reactions were monitored. A constant ratio (0.03%) of Nysosel 222 was used in the various combinations of temperature (150, 165 and 180,°C), stirring speed (500, 750 and 1000,rpm) and hydrogen pressure (1, 2 and 3,bar). Raising the temperature increased the formation of fatty acid isomers, whereas higher stirring rates decreased this formation, while changes in hydrogen pressure had no effect or slightly reduced it, depending on other parameters. Results also indicated that the trans fatty acid ratio increased with IV reduction, reached the highest value when the IV was about 70 and decreased at IV < 70 due to saturation. Selectivity values (S21) at that point ranged between 5.78 and 11.59. Lower temperatures and higher stirring rates decreased not only the trans isomer content but also the S21 values at significant levels. However, same effects were not observed with the changes in hydrogen pressure. It was determined that a high SMP does not necessarily mean a high SFC. Selective conditions produced samples with higher SFC but lower SMP, which is possibly because of higher trans isomer formation as well as lower saturation. [source] Aging of transformer insulating materials under selective conditionsEUROPEAN TRANSACTIONS ON ELECTRICAL POWER, Issue 5 2007I. Fofana Abstract In today's economic climate, it is important to know the condition, by means of suitable diagnostic tests, of the oil impregnated paper usable as primary insulation in equipment such as transformers, switchgear, bushings, cables, and their accessories. The aim of this paper is regarded as a main task to study the parameters that mostly influence the ageing process of oil/paper insulation used in transformers with preset moisture levels. A comparison is made between the performances of cellulose and Aramid papers. It is shown that Aramid paper is much less sensitive to water than cellulose paper. However, the addition of air (oxygen), via acid formation and oxidation in the oil, has a direct influence on the increase of the loss factor for both papers. The catalysts, that represent the metallic components in the transformer, accelerate the ageing process of the cellulose papers, while no influence on the ageing process of Aramid was observed. Oil ageing without a solid partner is insignificantly influenced by water, but accelerated by air-oxygen, via the moisture and acid formation, and oxidation processes. A direct influence on the increase of the loss factor and the decrease of electric strength particularly at low temperatures is to be noted. Copyright © 2006 John Wiley & Sons, Ltd. [source] Effect of carrot on quality improvement of sweet syrupy cheese ball (Rasgulla)INTERNATIONAL JOURNAL OF DAIRY TECHNOLOGY, Issue 3 2008MAHUYA BANDYOPADHYAY To evaluate the effect of carrot on the quality improvement of the sweet syrupy cheese ball known as Rasgulla, six types of Rasgulla samples containing carrot paste in the proportions of 0, 10, 20, 30, 40 and 50% were prepared and stored in closed containers at 25°C for 40 h. With increasing storage time the acidity of syrup, free fatty acid formation, absorptivity value and colour of all Rasgulla samples increased. The addition of carrot to chhana (analogous to cottage cheese) decreased acid and free fatty acid formation in Rasgulla syrup, decreased absorptivity, and also gave colour stability. Carrot concentration up to 30% improves the quality of Rasgulla. More than a 30% concentration of carrot reduced the oxidative stability of Rasgulla, while a more than 40% carrot concentration reduced its colour stability. Thus, the use of carrot up a concentration of 30% is suggested to increase the oxidative stability as well as the colour stability of Rasgulla. [source] Tyrosine metabolism in pigment-forming Yarrowia lipolytica strains isolated from English and European speciality mould-ripened cheese exhibiting a brown discolouration defectINTERNATIONAL JOURNAL OF DAIRY TECHNOLOGY, Issue 3 2007ALAN G WILLIAMS Yarrowia lipolytica s4fd was isolated from a UK-manufactured speciality mould-ripened cheese as the causative micro-organism of a brown surface discolouration spoilage defect. Comparative studies utilizing Y. lipolytica isolates indicated that inter-strain variations in pigment accumulation were attributable to differences in tyrosine uptake and metabolism to homogentisic acid. The range and activity profiles of proteolytic enzymes involved in tyrosine release and turnover in isolates that differed in pigment formation were, however, similar. Homogentisic acid formation was affected by physiological parameters, and approaches that may be developed by the cheesemaker to prevent spoilage losses associated with the development of the brown discolouration defect are discussed. [source] Evaluation of the fermentability of oat fractions obtained by debranning using lactic acid bacteriaJOURNAL OF APPLIED MICROBIOLOGY, Issue 4 2008G. Kedia Abstract Aims:, The overall kinetics of the fermentation of four oat fractions obtained by debranning using three potentially probiotic lactic acid bacteria were investigated. The main objective was to study the suitability of these fractions as fermentation media for the growth and the metabolic production of bacteria isolated from human intestine. Methods and Results:, The cell growth, lactic acid production and substrate uptakes of the three lactobacilli was monitored for 30 h. An unstructured mathematical model was used to describe and fit the experimental data. In the medium from fraction B (1,3% pearlings or ,-glucan-rich fraction) all strains reached the highest cell populations, maximum growth rates and maximum lactic acid productions. This could be because of the high levels of total fibre and ,-glucan of this fraction. Limited growth and lactic acid formation was found in medium A (0,1% pearlings or bran-rich fraction). Conclusions:, Medium B (1,3% pearling fraction) is the most suitable for fermentation and produces considerably higher probiotic cell concentrations. Significance and Impact of the Study:, Debranning technology could be used to separate fractions from cereal grains for the production of functional formulations with higher probiotic levels than the ones that were obtained with the whole grain. [source] Hydrothermal conversion of carbohydrate biomass to lactic acidAICHE JOURNAL, Issue 10 2010Xiuyi Yan Abstract We investigated the hydrothermal conversion of the carbohydrates including glucose, cellulose, and starch to lactic acid using NaOH and Ca(OH)2 as alkaline catalysts. Both catalysts significantly promoted the lactic acid formation. The highest yield of lactic acid from glucose was 27% with 2.5 M NaOH and 20% with 0.32 M Ca(OH)2 at 300°C for 60 s. The lactic acid yields from cellulose and starch were comparable with the yield from glucose with 0.32 M Ca(OH)2 at 300°C, but the reaction time in the case of cellulose was 90 s. The mechanism of lactic acid formation from glucose was discussed by identifying the intermediate products. Lactic acid may be formed via the formation of aldoses of two to four carbons including aldose of three carbons, which are all formed by reverse aldol condensation and double bond rule of hexose. This implies that carbon,carbon cleavage occurs at not only C3C4 but also at C2C3. © 2010 American Institute of Chemical Engineers AIChE J, 2010 [source] Phosphatidic acid formation is required for extracellular ATP-mediated nitric oxide production in suspension-cultured tomato cellsNEW PHYTOLOGIST, Issue 4 2010Daniela J. Sueldo Summary ,In animals and plants, extracellular ATP exerts its effects by regulating the second messengers Ca2+, nitric oxide (NO) and reactive oxygen species (ROS). In animals, phospholipid-derived molecules, such as diacylglycerol, phosphatidic acid (PA) and inositol phosphates, have been associated with the extracellular ATP signaling pathway. The involvement of phospholipids in extracellular ATP signaling in plants, as it is established in animals, is unknown. ,In vivo phospholipid signaling upon extracellular ATP treatment was studied in 32Pi -labeled suspension-cultured tomato (Solanum lycopersicum) cells. ,Here, we report that, in suspension-cultured tomato cells, extracellular ATP induces the formation of the signaling lipid phosphatidic acid. Exogenous ATP at doses of 0.1 and 1 mm induce the formation of phosphatidic acid within minutes. Studies on the enzymatic sources of phosphatidic acid revealed the participation of both phospholipase D and C in concerted action with diacylglycerol kinase. ,Our results suggest that extracellular ATP-mediated nitric oxide production is downstream of phospholipase C/diacylglycerol kinase activation. [source] | |||||||||||||