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Results 251 - 300 of 1130
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Pinheiro Eloi Sa Rovaris - - 2008
A central composite design was employed to optimize the extraction of pectin with citric acid. The independent variables were citric acid concentration (0.086-2.91% w/v) and extraction time (17-102 min). The combined effect of these variables on the degree of esterification was investigated. Results have shown that the generated regression models ...
Yılmaz Serkan - - 2008
Clastogenic properties of the food additive citric acid, commonly used as an antioxidant, were analysed in human peripheral blood lymphocytes. Citric acid induced a significant increase of chromosomal aberrations (CAs) at all the concentrations and treatment periods tested. Citric acid significantly decreased mitotic index (MI) at 100 and 200 mug ...
Robert Michaud M - - 2008
The midge, Belgica antarctica Jacobs, is subjected to numerous environmental stressors during its 2-year life cycle on the Antarctic Peninsula, and in response it has evolved a suite of behavioral, physiological, and life-cycle modifications to counter these stressors, but thus far only a limited number of biochemical adaptations have been ...
Solar Tina - - 2008
Glucosamine-6-phosphate (GlcN6P) deaminase seems to be the main enzyme in Aspergillus niger cells responsible for rapid glucosamine accumulation during the early stages of growth in a high-citric-acid-yielding medium. By determining basic kinetic parameters on the isolated enzyme, a high affinity toward fructose-6-phosphate (Fru6P) was measured, while in the reverse direction ...
Hayes John E - - 2008
Polymorphisms in the TAS2R38 gene provide insight to phenotypes long associated 6-n-propylthiouracil (PROP) and phenylthiocarbamide bitterness. We tested relationships between TAS2R38 genotype, taste phenotype, and fungiform papillae (FP) number in 139 females and 59 males (age range 21-60 years), primarily of European ancestry. DNA was analyzed for 3 polymorphic sites, ...
Mosqueda-Melgar Jonathan - - 2008
The effect of high-intensity pulsed electric field (HIPEF) combined with citric acid (0.5-2.0%, w/v) or cinnamon bark oil (0.05-0.30%, w/v) against populations of Escherichia coli O157:H7, Salmonella Enteritidis and Listeria monocytogenes in melon and watermelon juices were evaluated. Microbiological shelf-life and sensory attributes were also determined. Populations of E. coli ...
Djokić Stojan - - 2008
Formation of silver citrate/citric acid complexed solutions was investigated. Although, silver citrate is minimally soluble in water, it can successfully be dissolved in citric acid solutions. The maximum concentration of Ag(I) in solution is estimated at 23 to 25 g/L if the concentration of citric acid is at least 4 ...
Hemingway C A - - 2008
Hydroxyapatite is the main constituent of the dental hard tissues, and in vivo its dissolution in acids leads to the pathological condition of dental erosion. Food proteins which inhibit hydroxyapatite dissolution may find application as erosion-reducing agents in food and drink products. The aim of this study was to investigate ...
Anastassiadis Savas - - 2008
Current Review article summarizes the developments in citric acid production technologies in East and West last 100 years. Citric acid is commercially produced by large scale fermentation mostly using selected fungal or yeast strains in aerobe bioreactors and still remains one of the runners in industrial production of biotechnological bulk ...
De Silva Veronica - - 2008
Loblolly pine (LP, Pinus taeda) is the primary commercial species in southern forests of the US. Somatic embryogenesis (SE) is an effective technique to implement clonal tree production of high-value genotypes from breeding and genetic engineering programs. Unlike angiosperm embryos with attached cotyledons as seed storage organs, the diploid conifer ...
Lan Yeqing - - 2008
The influence of clay minerals on the reduction of Cr6+ by citric acid was investigated at pH values 4.0, 4.5 and 5.0 at 25 degrees C. The results indicate that montmorillonite and illite greatly accelerate the reduction reactions at pH 4.0 and 4.5, but their effects are dramatically reduced at ...
Andrews Gavin P - - 2008
The aim of this highly novel study was to use hot-melt extrusion technology as an alternative process to enteric coating. In so doing, oral dosage forms displaying enteric properties may be produced in a continuous, rapid process, providing significant advantages over traditional pharmaceutical coating technology. Eudragit L100-55, an enteric polymer, ...
Noordover Bart A J - - 2007
Citric acid (CA) was evaluated as a functionality-enhancing monomer in biobased polyesters suitable for coating applications. Model reactions of CA with several primary and secondary alcohols and diols, including the 1,4:3,6-dianhydrohexitols, revealed that titanium(IV) n-butoxide catalyzed esterification reactions involving these compounds proceed at relatively low temperatures, often via anhydride intermediates. ...
Mariño Faleh Tamimi - - 2007
In this study we have compared the effect of using acetic, glycolic, and citric acids on the brushite cement setting reaction and the properties of the resultant cement. The cement solid phase was made by mixing beta-tricalcium phosphate (beta-TCP), monocalcium dihydrogen phosphate anhydrate (MCPA), and sodium pyrophosphate, whereas the cement ...
López María-Isabel - - 2007
A study was made of the effects of irrigation management strategies during ripening on the quality of Spanish field-grown grapevine (Vitis vinifera L.) cultivars (Baladi, Airén, Montepila, Muscat Blanc à Petits Grains and Pedro Ximénez) grown under the "Montilla-Moriles" Appellation of Origin in Cordoba, Spain. From 1999 to 2002, two ...
Pecova R - - 2007
Different inhalation methods are used for cough reflex sensitivity (CRS) measurement. The single-breath method of tussigenic agent aerosol inhalation is widely used now. Comparison of two tussigenic agents--citric acid and capsaicin--in cough reflex sensitivity measurement was used in healthy volunteers. In 17 healthy volunteers (7 M, 10 F; mean age ...
Nishino Takashi - - 2008
The aim of this study was to clarify whether coughing elicited by airway irritation can modulate the sensation of air hunger. Using a visual analog scale (VAS), we measured air hunger for 30 s following breakpoint of a breath-hold in healthy young subjects who were asked to resume their breathing ...
Sugino Tomohiro - - 2007
We examined the effects of citric acid and l-carnitine administration on physical fatigue. In a double-blind, placebo-controlled, 3-way crossover study, 18 healthy volunteers were randomized to oral citric acid (2,700 mg/day), l-carnitine (1,000 mg/day), or placebo for 8 days. The fatigue-inducing physical task consisted of workload trials on a cycle ...
Imandi Sarat Babu - - 2008
Statistical experimental designs were applied for the optimization of medium constituents for citric acid production by Yarrowia lipolytica NCIM 3589 in solid state fermentation (SSF) using pineapple waste as the sole substrate. Using Plackett-Burman design, yeast extract, moisture content of the substrate, KH(2)PO(4) and Na(2)HPO(4) were identified as significant variables ...
Dotson Cedrick D - - 2007
In taste bud cells, two different T1R heteromeric taste receptors mediate signal transduction of sugars (the canonical "sweet" taste receptor, T1R2 + T1R3) and L-amino acids (the T1R1 + T1R3 receptor). The T1R1 + T1R3 receptor is thought to mediate what is considered the fifth basic taste quality "umami." However, ...
Trevino Lucia - - 2007
The influence of the physical structure of polyurethane matrix as a support in a solid state culture in tannase production and gallic acid accumulation by Aspergillus niger Aa-20 was evaluated. Three different polyurethane matrices were used as the support: continuous, semi-discontinuous and discontinuous. The highest tannase production at 2479.59 U/L ...
Min J S - - 2007
The effect of irradiation or organic acid treatment of raw chicken breast and thigh meat to control inoculated microorganisms and the production of biogenic amines (BA) was studied. Bacillus cereus, Enterobacter cloacae, and Alcaligenes faecalis were selected and inoculated into raw ground chicken breast and thigh meat at approximately 10(7) ...
Mollineau W M - - 2008
This study was conducted to identify the levels of fructose and citric acid, and sperm morphologies in agouti (Dasyprocta leporina) semen. These parameters may be important in identifying highly fertile semen from the agouti. The objectives were: (1) to investigate spermatozoal abnormalities in agouti semen and (2) to determine the ...
Li Hui - - 2008
An ultrasonically assisted extraction (UAE) technique was developed for the extraction of manganese from electrolytic manganese slag using a sulfuric acid-hydrochloric acid mixture (4:0.3, v/v) as solvent. The UAE conditions were optimized and the significance of variables affecting UAE tested. The determination of manganese was carried out by atomic absorption ...
Tasistro A S - - 2007
1. In a pen study, NH(3) flux estimates were performed when clean wheat straw or wood shavings were used as bedding materials in combination with two NH(3) control amendments: sodium bisulphate and a commercial premix of phosphoric + hydrochloric + citric acids. 2. Ammonia emissions from wood shavings were 19% ...
Benoit Isabelle - - 2007
The full-length gene that encodes the chlorogenic acid hydrolase from Aspergillus niger CIRM BRFM 131 was cloned by PCR based on the genome of the strain A. niger CBS 513.88. The complete gene consists of 1,715 bp and codes for a deduced protein of 512 amino acids with a molecular ...
Papanikolaou Seraphim - - 2008
Yarrowia lipolytica ACA-DC 50109 cultivated on olive-mill wastewater (O.M.W.)-based media, enriched with commercial-industrial glucose, presented an efficient cell growth. Parameters of growth were unaffected by the presence of O.M.Ws in the growth medium. In diluted O.M.Ws enriched with high glucose amounts (initial sugar concentration, 65 g l(-1)), a notable quantity ...
Zhou Feng - - 2007
To identify synergistic combinations of different food additives, the antimicrobial effects of thymol and carvacrol against Salmonella Typhimurium were assessed alone and in combination with various other preservatives including EDTA, acetic acid, lactic acid, and citric acid. Overall, growth of Salmonella Typhimurium was significantly inhibited in Mueller-Hinton broth containing thymol, ...
Candan Mehmet - - 2007
The antimicrobial activity of the acetone, chloroform, diethyl ether, methanol, and petroleum ether extracts of the lichen Parmelia sulcata and its salazinic acid constituent have been screened against twenty eight food-borne bacteria and fungi. All of the extracts with the exception of the petroleum ether extract showed antimicrobial activity against ...
Sierra V - - 2008
The intramuscular fat content and composition influence consumer selection of meat products. A study predicting the fatty acid (FA) profile of ground beef from the Longissimus thoracis of yearling bulls (n=100) using near infrared transmittance spectroscopy (NIT) was conducted. The samples were scanned using an Infratec 1265 Meat Analyzer which ...
Michaud M Robert - - 2007
Flesh flies can enhance their cold hardiness by entering a photoperiod-induced pupal diapause or by a temperature-induced rapid cold-hardening process. To determine whether the same or different metabolites are involved in these two responses, derivatized polar extracts from flesh flies subjected to these treatments were examined using gas chromatography-mass spectrophotometry ...
Nesci A - - 2007
Natural phytochemicals may be an alternative to synthetic chemicals for controlling fungal growth and mycotoxin production in stored maize. A key to progress in this field is to select the best natural maize phytochemicals to be applied in a storage maize ecosystem. This research was undertaken to evaluate the effects ...
Kalapos Miklós Péter - - 2007
The chemoautotrophic theory concerning the origin of life postulates that a central role is played in the prebiotic chemical machinery by a reductive citric acid cycle operating without enzymes. The crucial point in this scenario is the formation of pyrite from hydrogen sulfide and ferrous sulfide, a reaction suggested to ...
Amaral K F - - 2007
AIM: To assess the ex vivo cytotoxicity of EDTA and citric acid solutions on macrophages. METHODOLOGY: The cytotoxicity of 17% EDTA and 15% citric acid was evaluated on murine macrophage cultures using MTT-Tetrazolium method [3-(4,5-dimethylthiazol-2-yl)-2,5 diphenyl tetrazolium bromide]. A total of 5 x 10(5) cells were plated in medium culture ...
Eschenmoser Albert - - 2007
Encouraged by observations made on the course of reactions the HCN-tetramer can undergo with acetaldehyde, I delineate a constitutional and potentially generational relationship between HCN and those constituents of the reductive citric acid cycle that are direct precursors of amino acids in contemporary metabolism. In this context, the robustness postulate ...
Karbouj Rim - - 2007
In this work, we study aluminium (Al) leaching using three chelating agents (lactic acid, oxalic acid, and citric acid) that are commonly found in foods and beverages. We test acids, sodium, potassium and lithium salts of these three chelating agents. Aluminium concentrations are determined by using Graphite Furnace Atomic Absorption ...
Taguchi Tetsushi - - 2007
A novel glue consisting of human serum albumin (HSA) and citric acid derivative (CAD) was developed where the glue is named as CAD-A glue. In this adhesive, CAD works as a crosslinking reagent of HSA. For preparing crosslinking reagent CAD, using citric acid as a starting material, three carboxyl groups ...
Hoppu Pekka - - 2007
The purpose of this study was to characterise physically stable amorphous blends that were sticky (low glass transition temperature) in ambient conditions. The effects of composition, melting time and melting temperature were evaluated with respect to physical and chemical property. Citric acid anhydrate and paracetamol were melt-quenched as binary mixtures ...
Arnao Marino B - - 2007
Melatonin is a well-known animal substance, which has recently been detected in plant tissues. However, there are only a few studies concerning its possible physiological role in plants. In this paper, we investigate the possible effect of melatonin on the regeneration of lateral and adventious roots in etiolated hypocotyls of ...
Lotfy Walid A - - 2007
In this work, sequential optimization strategy, based on statistical designs, was employed to enhance the production of citric acid in submerged culture. For screening of fermentation medium composition significantly influencing citric acid production, the two-level Plackett-Burman design was used. Under our experimental conditions, beet molasses and corn steep liquor were ...
Qin Ruijun - - 2007
We studied the effects of a 2-day exposure to aluminum (Al), copper (Cu) and zinc (Zn) stress on root exudates and root apices of aseptically grown poplar (Populus tremula L.) cuttings. Aluminum induced root exudation of oxalate and citrate, Cu induced root exudation of oxalate, malate and formate, and Zn ...
Barrington Suzelle - - 2008
Aspergillus niger NRRL 567 was grown in an inert support material for citric acid production. Optimization of the medium components, including ethanol, methanol, phytate, olive oil and surfactant was carried out using "one-factor-at-a-time" and central composite design (CCD) methods. Optimization using "one-factor-at-a-time" was performed and the supplement of ethanol and ...
Vinaud Marina C - - 2007
Taenia crassiceps cysticerci is used as an experimental model to cysticercosis studies; however there are subcutaneous cases of cysticercosis caused by these cysticerci. It remains unclear in the literature the energetic and fatty acid metabolism in cestodes. Its metabolic study may provide knowledge of pathways that may serve as potential ...
Chatterjee Indranil - - 2007
The mechanisms underlying the persistence of the Staphylococcus aureus small-colony variant (SCV) are not fully elucidated. In this study, clinical thymidine-dependent SCVs displayed altered expression of citB, clpC, and arcA genes, reduced acetate catabolization, and enhanced survival. These results implicate the importance of changes in tricarboxylic acid cycle and acetic ...
Papagianni Maria - - 2007
Citric acid is regarded as a metabolite of energy metabolism, of which the concentration will rise to appreciable amounts only under conditions of substantive metabolic imbalances. Citric acid fermentation conditions were established during the 1930s and 1940s, when the effects of various medium components were evaluated. The biochemical mechanism by ...
Lotfy Walid A - - 2007
Ultraviolet-irradiation (UV), ethyl methane sulfonate (EMS) and acridine orange (AO) were used to induce citric acid overproduction mutations in Aspergillus niger UMIP 2564. Among 15, eight of the mutant derivatives, were improved with respect to citric acid production from sucrose in batch cultures. Maximum product yield (60.25%) was recorded by ...
Vali Anahita
<b>Background and Aims:</b> Treatment of plane warts is problematic, methods such as cryotherapy and cauterization is associated with high recurrence rate, risk of scar, pain and high cost. Topical tretinoin causes irritant contact dermatitis that limited its use. Citric acid was used in treatment of warts in traditional medicine of ...
Cai F - - 2007
Casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) has been shown to remineralize enamel subsurface lesions in situ. The aim of this study was to investigate the effects of CPP-ACP in a fruit-flavoured sugar-free chewing gum containing citric acid on enamel remineralization, and acid resistance of the remineralized enamel, using an in situ ...
Pakdil N B - - 2007
This paper reports on the effects of inorganic acids (sulphuric acid, hydrochloric acid, nitric acid) and organic acids (citric acid, oxalic acids) for phosphorus recovery from sludge and struvite precipitation results. It was observed that both inorganic acid and organic acids were effective at phosphorus release. The studies on precipitation ...
Berovic Marin - - 2007
Citric acid is a commodity chemical produced and consumed throughout The World. It is used mainly in the food and beverage industry, primarily as an acidulant. Although it is one of the oldest industrial fermentations, its World production is still in rapid increasing. Global production of citric acid in 2007 ...
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