Showing papers on "Citric acid published in 1975"

Metabolic changes in the cerebral cortex of the rat induced by intravenous pentothalsodium.

Abstract: The effects of thiopental on cerebral metabolism were evaluated by means of measurements of cerebral metabolic rate for oxygen (CMRo2) and of tissue levels of organic phosphates, glycolytic substrates, citric acid cycle intermediates and selected amino acids. Shortly after the beginning of thiopental administration, CMRo2 was reduced to half the normal value, and there were signs of retardation of glycolytic flux at the phosphofructokinase step. Inhibition at this regulatory enzymatic step could be related to an increase in phosphocreatine and a fall in inorganic phosphate concentration. The rise in phosphocreatine, and the unchanged levels of ATP, ADP and AMP demonstrate that induction of anaesthesia with thiopental is unrelated to energy failure. Changes in citric acid intermediates included a fall in malate, and probably also in citrate, α-ketoglutarate and fumarate, with a tendency towards reduction in the pool of citric acid cycle intermediates; and the amino acid changes were dominated by a progressive rise in aspartate. It is suggested that these changes are secondary to a reduced rate of pyruvate delivery, and to a decrease in malate/oxaloacetate ratio.

Citrate utilization in milk by Leuconostoc cremoris and Streptococcus diacetilactis.

Abstract: Citrate utilization and diacetyl, acetoin and acetaldehyde production by 2 strains each of Leuconostoc cremoris and Streptococcus diacetilactis in milk were studied. With the leuconostoc bacteria no growth and little citrate utilization occurred unless a stimulant (yeast extract) was present, when complete utilization of citrate without concomitant production of diacetyl or acetoin was obtained. The addition of Mn2+ stimulated growth and citrate utilization in the presence of yeast extract. Addition of citric acid after 65-h growth resulted in diacetyl and acetoin production. Destruction of diacetyl and acetoin occurred when the citric acid level fell to c. 1000 and 600 μg/g in the case of Leuc. cremoris FR8-1 and CAF1, respectively. Only strain FR8-1 produced acetaldehyde. In contrast, Str. diacetilactis produced diacetyl, acetoin and acetaldehyde concomitant with citrate utilization.

Synergistic flavor enhancing coatings for cat food compositions comprising citric and phosphoric acids

Abstract: A cat food composition of improved acceptability to cats is provided as well as a process for generally enhancing the palatability of dried or intermediate moisture cat foods wherein the cat food composition is coated with a synergistically effective flavor enhancing mixture comprising between about 87 to 13 parts by weight of phosphoric acid to 1 part by weight of citric acid wherein said coating is applied on the composition to provide a level of phosphoric acid in the cat food product of at least about 0.5% by weight. Cat food compositions containing the synergistically effective coating are significantly more palatable to cats than compositions which contain only citric or phosphoric acid as palatability enhancers.

Solutions for cleaning surfaces of copper and its alloys

Abstract: of the Disclosure SOLUTIONS FOR CLEANING SURFACES OF COPPER AND ITS ALLOYS A solution for pickling copper and its alloys contains one or more of such mineral acids as sulphuric acid or phosphoric acid in combination with hydrogen peroxide and such a hydroxy acid as citric acid or gluconic acid together with a nitrogen combination of the type substituated tria-zole and/or a tertiary amine of the general formula in which R is an aliphatic carbon chain containing less than 24 carbon atoms and the sum of n1 and n2 is less than 30.

Utilization of brewery spent grain liquor by Aspergillus niger.

Abstract: Aspergillus niger was found capable of rapidly converting about 97% of the sugar from brewery spent grain liquor to fungal mass. The yield of dry mycelium, based on the sugar consumed, was approximately 57%. This fungus produced 1.10% titratable acid calculated as citric acid and reduced the biochemical oxygen demand by 96%.

Arginine deficiency and orotic aciduria in mammals.

Abstract: Dietary arginine deficiency in rats causes significant increases in urinary excretion of urea, citric acid and orotic acid independently of feed intake. Urea excretion during arginine deficiency depends upon the diet, sex, age, and species. Thus urea excretion has limitations as an indicator of arginine availability. Although elevated urinary citric acid during arginine deficiency is more consistently observed, it may be influenced by citric acid in natural dietary ingredients. Orotic acid excretion, however, appears to be a reliable indicator of available dietary arginine based upon studies in rats, mice, hamsters, guinea pigs, rabbits, and dogs.

Thermal Inactivation of Conidia From Aspergillus flavus and Aspergillus parasiticus

Abstract: Conidiospores from one strain of Aspergillus flavus and two of Aspergillus parasiticus were thermally inactivated in menstrua at pH values of 3.5, 4.5, 5.5, and 6.0. These values were obtained with the following buffering systems: sodium acetate and acetic acid, citric acid and Na2HPO4, potassium acid phthalate (KHP)-HCl and KHP-NaOH, and KH2PO4 and NaOH. Heating of conidia in a menstruum adjusted to pH 7.0 with KH2PO4 and NaOH served as the control. Use of the sodium acetate and acetic acid buffering system resulted in an increase in the rate at which conidia were inactivated when the pH was decreased. Use of the citric acid and Na2HPO4 buffering system resulted in increased thermal resistance for the conidia as the pH was decreased; however, the degree of increased thermal resistance was strain dependent. When the KHP-HCl and KHP-NaOH buffers were used, conidia were inactivated more rapidly than in the control at the higher pH values and more slowly than in the control at the lower pH values. An increas...

Antimicrobial compositions employing certain betaines and certain amine oxides

Abstract: There is provided an antimicrobial composition of low toxicity having enhanced gram positive and gram negative activity and comprises: (a) an acyl-N-betaine (0.1 part - 40.0 parts, by weight), (b) an alkyl-N,N-dimethylamine oxide, an alkyl-N,N-dihydroxyethylamine oxide, or an acylamido t-amine oxide (0.1 part - 40.0 parts, by weight), and (c) a protonating agent, such as hydrochloric acid, acetic acid or citric acid in an amount sufficient to adjust the pH of the overall composition to about 5.5 or below. The composition exhibits deodorizing properties and, particularly, its use exhibits long term inhibition of body odor.

Effervescent dipeptide sweetener tablets

Abstract: Combining a readily soluble form of L-aspartyl-L-phenyl methyl ester (APM) with an effervescent calcium carbonate system and citric acid, when compressed into tablet form, produces an effervescent APM tablet having superior solubility and stability and is devoid of characteristic lingering sweet aftertaste.

Antimicrobial compositions employing certain substituted alanines and certain t-amine oxides

Abstract: There is provided an antimicrobial composition of low toxicity having enhanced gram positive and gram negative activity and consists essentially of: A. An alkylsubstituted alanine (0.1 part - 40.0 parts, by weight), B. an alkyl-N,N-dimethylamine oxide, an alkyl-N,N-dihydroxyethylamine or an acylamido t-amine oxide (0.1 part - 40.0 parts, by weight), and C. a protonating agent, such as hydrochloric acid, acetic acid or citric acid, in an amount sufficient to adjust the pH of the overall composition to about 5.5 or below. The composition exhibits skin degerming, cleansing, and deodorizing properties and, particularly, its use exhibits long term inhibition of body odor.

Partial Purification of a Growth Factor from Orange Juice Which Affects Citrus Tissue Culture and Its Replacement by Citric Acid

Abstract: Orange ( Citrus sinensis L. Osbeck) tissue cultures required a supply of orange juice to the medium for their vigorous growth. The growth-promoting activity of juice seemed to involve both cell division and cell enlargement. Juice had no promotive activity in bioassays for auxins, gibberellins, and cytokinins. The growth promoting activity of juice was mostly transferred into 1-butanol upon partition at pH 2. Gas chromatographic analysis of this acid 1-butanol fraction revealed large amounts of citric acid and negligible amounts of other organic acids. Supply of pure citric acid to the medium, alone or in combination with different concentrations of juice, indicated that citric acid replaces most of the requirement for juice. It seems that citric acid, which is a natural component of citrus juice, is responsible for the major part of the growth-promoting activity of the juice. The significance of citric acid as a growth factor in tissue cultures and the reasons for the dependence of citrus tissue cultures on external supply of citric acid are discussed.

Process of separating citric acid and/or isocitric acid or their salts from aqueous solutions

Abstract: The process of separating citric acid and/or isocitric acid and their salts from aqueous solutions containing said acids or their salts, and especially from fermentation solutions, consists in contacting said solutions under pressure with a permselective membrane. The material composing said membrane has introduced thereinto acid or basic groups so as to yield membranes of predetermined swelling power. Preferred membranes are those consisting of polyimide or polyamide polycondensation products which are modified by acid or basic groups, of polysulfones modified by acid groups, or of vinyl polymers modified by acid or basic groups. Adjustment of the starting solutions to a pH lower than 3.0 is advantageously effected by means of polyvinylsulfonic acid.

Calcium oxalate and the von Kossa method with reference to the influence of citric acid.

Abstract: Crystals of calcium oxalate in pathological material and artificially precipitated in the absence or presence of citric acid in gelatin models were examined by polarized light and treated with silver nitrate under a variety of conditions. It was found that the intensity of the staining reaction was largely proportional to the strength of the silver solution, and was enhanced in in vitro studies by the presence of citric acid. Staining was also influenced by the crystal form, which was itself related to the absence or presence of citric acid.

Complex Formation between the Uranyl Ion and Citric Acid

Abstract: A method to facilitate the analysis of the complex formation by a polybasic acid has been applied to the study of uranyl citrate complexes. The amount of the uranyl ion in equilibrium with the complexing agent was determined by the cation-exchange method. In this experiment, the uranyl-ion concentration was kept within a 105–106 M range in order to eliminate polymeric species. By using a series of solutions prepared so as to keep [H3Cit−] nearly constant and to vary [H2Cit2−] and [HCit3−] in the 2.2–2.9 pH range, it has been found that three kinds of complexes, UO2H3Cit+, UO2H2Cit, and UO2HCit−, were present in the solution. Approximate values of their formation constants were obtained.

The complete ionization scheme for citric acid

Abstract: The microacidity constants for citric acid have been redetermined from pH titrations of citric acid and selected methyl esters in aqueous solution at 25°C and at two ionic strengths. The results obtained differ from those previously published. Calculated acidity constants, derived from a careful consideration of the empirical substituent effect, are also given and are in reasonable agreement with the experimental acidity constants.

Vacuum treating fruit pieces in aqueous solutions consisting of sodium bisulfite or sodium sulfite and citric acid

Abstract: Fruit is prepared for refrigerated storage by cutting the fruit into convenient pieces, and then subjecting the fruit to soaking under vacuum in a solution containing sodium bisulfite or sodium sulfite and citric acid in definite ranges. These ranges are preferably inversely related in a substantially straight-line relationship, so that the high end of one range is used in conjunction with the low end of the other. The fruit pieces are also preferably immersed in a preliminary holding solution containing sodium bisulfite or sodium sulfite and table salt prior to the soaking. Fruit prepared in this way can be held indefinitely under ordinary refrigeration without freezing. The process is particularly suitable for apples.

Process of suppressing odors employing deodorants containing esters of citric acid

Abstract: A process of suppressing body odor comprising applying a substantially anhydrous cosmetic preparation for suppressing body odor containing as a deodorant an ester of citric acid or acetylcitric acid with an aliphatic alcohol having from 1 to 6 carbon atoms or an alicyclic alcohol having 5 to 6 atoms.

Process and bath for the metallization of synthetic-resin

Abstract: A process for the chemical coating of synthetic-resin bodies with nickel or copper utilizing an activation step in which the bath comprises: 0.1 to 20 g gelatin or gum arabic as the protective colloid, 1 to 5 g tartaric acid or citric acid, 1 to 5 g sulfuric acid or hydrochloric acid, 0.1 to 5 g palladium sulfate, 1 to 20 g maleic acid or 1 to 6 g fumaric acid as poly basic carboxylic acids, and water to a volume of 1 liter. The subsequent treatment with the chemical plating bath is carried out without an intervening acceleration treatment.

Ascorbic acid and blood lipid and uric acid levels of students.

Abstract: Serum lipid and uric acid levels were investigated in two groups of healthy young students. Each member of the control group was given 1 g of citric acid, and each member of the experimental group 4 g of L-ascorbic aicd daily for 4 months. Blood samples were drawn every month and leucocyte ascorbic acid, serum ascorbic acid, cholesterol, free fatty acids, triglycerides and uric acid were determined. The ascorbic acid did not cause dramatic changes in lipid parameters, and no evidence could be found that ascorbic acid raises serum uric acid levels.

Kinetic studies on citric acid production by Aspergillus niger. I. Phases of mycelium growth and product formation.

Abstract: The physiology and growth kinetics of Aspergillus niger B-64-5 in shaken culture were studied, five successive phases of citric acid fermentation being distinguished. Growth was found to be diauxic, spore germination being followed by an exponential growth phase, then a period of growth disturbance, and last of all a phase of secondary growth, characterized by a constant coefficient of growth decline appeared. The citric acid production started in the phase of growth disturbance. The chief increase in citric acid concentration took place in the production phase, i.e. in the last fermentation phase.

The effect of inorganic salts and some biologically important compounds on the incorporation of 1-14C acetate into aflatoxins by resting mycelia of Aspergillus parasiticus.

Abstract: Zn++, Mg++, and Mn++ ions at certain concentrations, stimulated the incorporation of [1-34C] acetate-into aflatoxins by resting mycelia ofAspergillus parasiticus suspended intris-HC] buffer of pH 7.2. Ba++ gave consistant stimulation over a wide range of concentrations. Ethanol markedly inhibited the incorporation. Of the tricarboxylic acid cycle intermediates, citric acid gave the maximum stimulation.

Effect of minor constituents and additives upon peroxidation of oil in peanut butter

Abstract: Metalloproteins and ionic iron and copper salts are major catalysts of fatty acid peroxidation, but chelating agents, such as ethylenediaminetetraacetic acid and citric acid in water, can retard or reduce this catalytic effect. To extend shelf-life and retain the high quality of peanut butter, methods to prevent or decrease the catalytic effect of these metalloproteins and salts were conducted. Chelating agents suspended in inert solvents (mineral oil) were not as effective as when they were added in water. Depending upon the concentration, water can act as a prooxidant or an antioxidant in peanut butter.