Showing papers on "Citric acid published in 1980"

Hypocitraturia in patients with gastrointestinal malabsorption.

Abstract: We measured serum and urinary citrate, oxalate, calcium, and magnesium in 22 normal subjects and in 16 patients with malabsorption. The patients had subnormal levels of serum citrate and magnesium during fasting, subnormal 24-hour levels of urinary citrate, magnesium, and calcium, and excessive levels of urinary oxalate. Daily citrate excretion averaged only 15 per cent of normal. The hypocitraturia in the patients resulted from a subnormal filtered load of citrate and abnormally high net tubular reabsorption of the anion. An oral citrate supplement raised both the serum concentration and the filtered load of citrate to normal fasting values, but net tubular reabsorption remained abnormally high and urinary excretion abnormally low. Intramuscular magnesium sulfate, which corrected the hypomagnesemia and hypomagnesuria, had no effect on serum citrate or its filtered load. Nevertheless the injection restored net tubular reabsorption of citrate to normal and partially improved the hypocitraturia. Fu...

Chelating, film‐forming, and coagulating ability of the chitosan–glucan complex from Aspergillus niger industrial wastes

Abstract: Waste mycelia of Aspergillus niger from a citric acid production plant are simply treated with boiling 30-40% NaOH aqueous solutions for 4-6 hr to obtain the insoluble chitosan-glucan complex whose infrared, ESR, and x-ray diffraction spectra are reported. A number of transition- and post-transition-metal ions are chelated and collected by chitosan-glucan with higher yields than by animal chitosan. Immediate flocculation occurs upon mixing chitosan-glucan dispersions with alginate and polymolybdate solutions. Membranes are also obtained from chitosan-glucan dispersions in acetic acid or in chloral and dimethyl formamide mixtures.

Regulation of citric acid production by oxygen: Effect of dissolved oxygen tension on adenylate levels and respiration in Aspergillus niger

Abstract: The mechanism of the control of citric acid accumulation by oxygen was investigated by means of pilot plant fermentation using Aspergillus niger. The critical dissolved oxygen tension (DOT) for oxygen uptake of this fungus was about 18–21 and 23–26 mbar for trophophase and idiophase, respectively. Minimal DOT for citric acid production was about 25 mbar. Citric acid production increased steadily between 40–150 mbar. Short time changes in the DOT produced immediate, irreversible changes in the rate of product formation. Adenine nucleotides paralleled growth but showed no evidence for control function in the oxygen effect on citric acid fermentation. A branched respiratory system was identified by experiments using specific inhibitors (antimycin, cyanide, azide, rotenone, amytal and salicylhydroxamic acid). Growth was sensitive towards inhibitors of the standard respiratory chain, but only slightly sensitive towards salicylhydroxamic acid (SHAM). Citric acid synthesis was highly sensitive towards SHAM during trophophase, but sensitive towards antimycine during idiophase. Interruptions in aeration cause an impairment of the SHAM sensitive oxidase during trophophase, and of the antimycin sensitive oxidase during idiophase.

Infrared study of the adsorption of hydroxycarboxylic acids onα-FeOOH and amorphous Fe (III)hydroxide

Abstract: The adsorption of lactic acid, meso-tartaric acid,l-tartaric acid and citric acid onα-FeOOH and amorphous Fe(III)hydroxide was investigated by i.r. spectroscopy. The results indicate that adsorption is based on partial replacement of the surface hydroxyl groups by carboxylate groups. For meso-tartaric acid onα-FeOOH and for lactic acid andl-tartaric acid on amorphous Fe(III)hydroxide deprotonated alcoholic hydroxyl groups participate in the surface complex formation. A tentative model for the adsorption on the (100) face ofα-FeOOH is presented.

Influence of manganese on morphology and cell wall composition of Aspergillus niger during citric acid fermentation.

Abstract: Morphology and cell wall composition of Aspergillus niger were studied under conditions of manganese sufficient or deficient cultivation in an otherwise citric acid producing medium. Omission of Mn2+ (less than 10-7 M) from the nutrient medium of Aspergillus niger results in abnormal morphological development which is characterized by increased spore swelling, and squat, bulbeous hyphae. Fractionation and analysis of manganese deficient cell walls revealed increased chitin and reduced β-glucan contents as well as reduction of galactose containing polymers, as compared to cell walls from manganese sufficient grown hyphae. Addition of copper induced the same effect as manganese deficiency, both on morphology and cell wall composition. Addition of cycloheximide also produced a very similar type of morphology with increased chitin and reduced β-glucan contents of the cell wall but its effect on galactose was less pronounced.

Determination of serum-phosphate without deproteinization by ultraviolet spectrophotometry of the phosphomolybdic acid complex.

Abstract: Phosphate may be determined in serum without deproteinization as the phosphomolybdic acid complex by UV-spectrophotometry. The rate of complex formation is dependent on the acidity and the concentration of molybdate. The photometric measurements should be performed at a longer wavelength than in maximum absorptivity of the phosphomolybdic acid complex to permit practical high concentrations of molybdate in the reagents. Citric acid will hinder the complex formation, but will not interfere with the stability of the phosphomolydbic acid. The phosphomolybdic complex is determined by adding citric acid to the samples before (blank) and after (test) the molybdate. The analytical procedure has been automated on a Greiner GSA II, Greiner Electronics, Switzerland.

Methods and compositions for removing deposits containing iron sulfide from surfaces comprising basic aqueous solutions of particular chelating agents

Abstract: Methods and compositions for removing deposits containing iron sulfide from surfaces with minimal hydrogen sulfide evolution. A composition comprised of a basic aqueous solution of a chelating agent selected from the group consisting of citric acid, oxalic acid, alkylene polyamine polyacetic acids and mixtures of such chelating agents having a pH in the range of from about 8 to about 10 is brought into contact with the deposits for a period of time sufficient for the deposits to be dissolved therein.

Complex formation of nickel(II) ions with citric acid in aqueous solution: a potentiometric and spectroscopic study

Abstract: From a potentiometric and visible spectrophotometric study of the nickel(II)-citric acid (H3L) system in the pH range 3-6, four complexes, NiL-, NiHL, NiH2L+ and NiL24-, have been characterized. Stability constants for the formation of these complexes have been determined at 25°C in 0.1 mol dm-3 KCl. The results suggest that the hydroxy group of citric acid is coordinated in the nickel-citrate complexes.

Role of nitrite in cured meat flavor: chemical analysis

Abstract: Hams treated with 2.5% salt and varying concentrations of sodium nitrite, butylated hydroxytoluene (BHT), and citric acid were evaluated by means of thiobarbituric acid (TBA) values, formation of fluorescent products, hexanal and 2,4-decadienal, and sensory analyses. Results demonstrate that nitrite significantly reduces (p < 0.05) lipid oxidation in pork stored aerobically at 4°C. Meat treated with 0.02% BHT or 1000 mg/kg of citric acid also reduced TBA values, although these compounds were not as effective as 50 mg/kg of sodium nitrite. A significant relationship (p < 0.05) was established between off-odor/flavor formation and both TBA values and the production of fluorescent products during the first 7 days of storage. However, the relationship between fluorescent products and off-odors/flavors was not significant at 14 days. Significantly lower (p < 0.05) levels of hexanal and 2,4-decadienal were found in meat treated with nitrite, BHT or citric acid compared to samples containing only salt.

Formation constants for magnesium and calcium citrate complexes

Abstract: centration formation constants for magnesium and calcium citrate complexes have been redetermined from pH titrations of citric acid in the absence and presence of the divalent metal ions in aqueous solution at 2° Values for the constants, corrected for the presence of potassium citrate complex, are presented and critically compared with literature values. Values for the formation constants of strontium and barium citrate complexes are also reported.

Sorbic acid inhibition of clostridium botulinum in nitrite‐free poultry frankfurters

Abstract: Chicken and turkey frankfurter emulsions and ground commercial frankfurters were treated with sorbic acid or potassium sorbate together with several acidulating agents. These were inoculated with 400 spores/g of a mixture of 21 strains of C. botulinum (12 of type A, 9 of type B) and canned under vacuum in 208 × 107 aluminum tab cans. The cans were temperature abused at 30°C. Chicken emulsions with sodium acid pyrophosphate (used for commercial frankfurters) showed can swelling in 2 days; turkey emulsion cans swelled in 4 days. The mean swell times for chicken and turkey were, respectively: 7 and 15 days with 0.52% potassium sorbate and 13 and 35 days with 0.40% sorbic acid. Acidification of emulsions with 3PO4 or glucono-δ-lactone to a pH as low as 5.4 did not increase the mean swell times; however, in combination with 0.4% sorbic acid the mean swell times were increased over those of the sorbic acid alone. Citric acid increased mean swell times in turkey but not in chicken emulsions. For poultry emulsions and poultry frankfurters commercially prepared with 0.2% sorbic acid, acidification with H3PO4 to pH 5.7 resulted in appreciable increases in mean swell times; 0.4% sorbic acid without 3PO4 was more effective. Indigenous microflora, causing gas production in the cans, were also inhibited by 0.4% sorbic acid and by 3PO4 acidified 0.2% sorbic acid. Finished frankfurters generally behaved the same as the emulsions in C. botulinum inhibition; however, they gave better protection than the emulsions when both were treated with 0.2% sorbic acid plus 3PO4.

Extraction of organic acids from aqueous solutions

Abstract: Organic acids, such as citric acid, malic acid and lactic acid, can be extracted from aqueous solutions thereof by contacting such solutions with a mixture of a water immiscible amine and a water immiscible organic acid dissolved in a suitable water immiscible solvent

Non-gelling inorganic salt crutcher slurries

Abstract: Gelation and setting of desirably miscible and pumpable crutcher slurries comprising sodium carbonate, sodium bicarbonate and sodium silicate in an aqueous medium are retarded and often prevented by the addition to such medium of a citric material, such as citric acid and/or water soluble citrate, and magnesium sulfate. Alternatively, magnesium citrate may be employed. The addition of the citric material and magnesium sulfate (or magnesium citrate) lengthens appreciably the workable crutcher time before setting, increasing it over such working time for similar crutcher mixes containing the citric material but not containing magnesium sulfate. The improved workability of the crutcher mix permits the making of higher solids content crutcher slurries, thereby resulting in significant energy savings and increases in production rates when the crutcher slurries are subsequently spray dried to free flowing inorganic salt base bead form, from which detergent compositions may be made by post-spraying with nonionic synthetic organic detergent in liquid state.

cAMP concentration, morphological differentiation and citric acid production in Aspergillus niger

Abstract: The possibility that adenosine 3′,5′ monophosphate exerts an effect on citric acid production by Aspergillus niger by influencing pellet morphology has been investigated. The effect of pH and inoculum size on pellet formation, citric acid production, and intracellular and extracellular cAMP levels were studied. High levels of intracellular and extracellular cAMP in the later stages of the fermentation, the period of maximum citric acid formation, were associated with those treatments which gave pellets of intermediate size. The highest cAMP levels were associated with those treatments which gave the highest citric acid titre. It was concluded that high cAMP levels are principally associated with an optimum physiological state for citric acid production and that cAMP levels do not vary directly with pellet size.

[Citric acid excretion in stone-formers and healthy controls on normal and standard diet (author's transl)].

Abstract: The citric acid excretion and concentration in 24 hours urine was measured in 70 stone-formers and 16 normal subjects (controls) on normal food intake followed by 9 days on a standard diet. On days 9 and 10 on the standard diet urine was collected in 3 hours portions and citric acid and calcium was measured. From day 7 to day 10 on standard diet we found only a slight change in the 24-hour excretion of citric acid ("steady state"). The citric acid excretion and concentration is significantly lower in stone-formers than in healthy controls. In both groups there is a sinusoid rhythm in citric acid excretion and concentration throughout the 24 hour period. The calcium concentration is at its maximum when the citric acid concentration is at its minimum.

Stable composition of S-adenosyl-L-methionine

Abstract: A stable composition of S-adenosyl-L-methionine is disclosed which includes a salt of S-adenosyl-L-methionine and a pharmaceutically acceptable, water-soluble salt of a bivalent or trivalent metal. The salt of S-adenosyl-L-methionine is, for example, a salt of S-adenosyl-L-methionine with hydrochloric acid, sulfuric acid, p-toluenesulfonic acid, phosphoric acid, formic acid, acetic acid, citric acid, tartaric acid, or maleic acid; or a double salt of S-adenosyl-L-methionine with the foregoing acids. The salt of a bivalent or trivalent metal is, for example, calcium chloride, ferric chloride, magnesium chloride, or magnesium sulfate. A process for preparing the composition is also disclosed. The composition is suitable for preparing pharmaceutical preparations of S-adenosyl-L-methionine.

Physiology and metabolism of two alkane oxidizing and citric acid producing strains of Candida parapsilosis

Abstract: The activity of enzymes of the tricarboxylic acid (TAC) and glyoxylate (GC) cycles in Candida parapsilosis (wild type KSh 21 and mutant 337) were studied under different physiological and metabolic conditions.

Physiology and metabolism of two alkane oxidizing and citric acid producing strains of Candida parapsilosis: II. Effect of carbon sources on morphology, lipid content, and fatty acid composition, on enzymes of the citric acid- and glyoxylate cycles and catalase

Abstract: SummaryThe study of the effect of different carbon sources reflected the following results:1.Candida parapsilosis (wild type and mutant) could not utilize citrate and glyoxylate and could grow well on pyruvate, acetate and to some extent on α-ketoglutarate, trans-aconitate, isocitrate and succinate.2.Cells grown on tetradecane and pentadecane formed much more pseudomycelium than cells grown on the other tested carbon sources.3.The catalase activities of the cells grown on tetradecane were generally much higher than those of the cells grown on acetate or glucose.4.The tetradecane-grown cells of both organisms contain more lipid than glucose-, acetate- or succinate-grown cells.5.Among the fatty acids found in the cells, the even-numbered dominate. A few odd-numbered were detected.6.Enzymes of the glyoxylate cycle had very high activities on acetate and tetradecane, but very low ones on glucose and succinate medium. The two strains had with all the carbon sources a high citrate synthase activity.7.High concentrations of glucose (2.5% and more) repressed the enzyme activities tested while acetate abolished this effect. Many authors have reported the fermentative production of citric acid from hydrocarbons (Nakanishi et al. 1972; Puklowski et al. 1976; Schröder 1976), the effect of hydrocarbons on the morphology of n-alkane degrading yeasts (Hirai et al. 1972), the effect of substrate on the fatty acid composition of hydrocarbon utilizing microorganisms (Dunlap and Perry 1967; Mishina et al. 1973; Source on enzymes of the tricaboxylic acid- and glyoxylate cycle (Gosling and Duggan 1971; Lozinov et al. 1976; Kleber and Aurich 1973, 1974; Fritsche 1968; Nabeshina et al. 1977), and catalase activity of hydrocarbon metabolizing yeasts (Teranishi et al. 1974a, b). Each author used a different yeast strain and no work has reported these different physiological studies for one organism at a time.In a previous work we reported the effect of pH, temperature, age and trans-aconitate on growth and enzymes of Candida parapsilosis (Omar and Rehm 1980).The following paper deals with experiments on the utilization of various carbon sources and on the comparison of enzyme activities of the TCC and glyoxylate cycle, catalase and fatty acid composition of C. parapsilosis.

Production of acetoin and diacetyl by lactic acid bacteria in skimmed milk with added citrate and pyruvate.

Abstract: Thirty-two strains of starter cultures and lactic acid bacteria belonging to the genera Streptococcus, Leuconostoc and Lactobacillus were studied for their ability to produce acetoin (A) and diacetyl (D) from citrate and pyruvate added separately to skim milk and from pyruvate added to peptone-yeast extract-glucose broth (PYG). The largest amount of A + D was produced from citrate and by the citrate fermenters Streptococcus cremoris AM2, Str. faecalis, Leuconostoc citrovorum ATCC 8082, L. Gasei ATCC 393, L. Gasei ssp. alactosus and L. xylosus. Some strains of Str. cremoris, Str. thermophilus, some strains of L. Gasei, L. plantarum and L. coryniformis on the contrary produced more A + D from pyruvate than from citrate. Str. cremoris AM2 should be designated as Str. diaceticremoris like Str. diacetilactis. PYG was more favourable than skim milk for production of A + D from pyruvate by Str. lactis, some strains of Str. cremoris, Str. faecalis and lactobacilli. Pyruvate as a sole source of carbon gave a poor yield of A + D compared to itself in the presence of glucose in case of most of the streptococci and all of the lactobacilli. The largest amount of diacetyl was produced by 70% of the streptococci from citrate added to skim milk, and by the great most of the lactobacilli from pyruvate in PYG medium.

Contact lens washing agent

Abstract: PURPOSE:To prevent damage by performing physical and chemical washing by the formation of bubbles in a prescribed amount of purified water without rubbing a lens, by using tablets or granules consisting of NaHCO3 organic or inorganic acid, or acid salt and oxygen and a surface active agent. CONSTITUTION:Tablets or granules are prepared which consist of about 10- 70wt% NaHCO3, about 1-30wt% organic or inorganic acid, such as citric acid and boric acid, acid salt, such as NaH2PO4, especially KH2PO4 or citric acid nearly a half the weight of NaHCO3, powdery or flaky nonionic surface active agent (preferably 1,000 average molecular weight of oxyethylene oxypropylene block polymer), and about 0.1-10 total wt% proteolytic enzyme, lypolytic enzyme mucolytic enzyme, and phospholypase. The 1g tablets are dissolved in 100cc purified water and after a contact lens is dipped in it for about 1-5hr, the water is substituted by the physiological salt solution to obtain the clean lens.

Preservative for food

Abstract: PURPOSE: A preservative for foods exhibiting improved controlling effect on the propagation of microorganisms, not deteriorating the taste of foods, and not changing the properties of protein and other ingredients, obtained by blending ethanol with a saccharide, organic acid, etc. in a specific ratio. CONSTITUTION: 100pts.wt. ethanol is blended with 10W30pts.wt. saccharide, e.g., glucose, fructose, etc. and/or sugaralcohol, e.g., mannitol, sorbitol, etc., 0.2W 5pts.wt. organic acid, e.g., malic acid, citric acid and/or its salts, 0.2W5pts.wt. amino acid, e.g., glycine, lysine, etc. and/or its salt, and, if necessary, water and other additives. COPYRIGHT: (C)1982,JPO&Japio

Intracellular Concentrations of Citric and Isocitric Acids in Cultures of the Citric Acid-excreting Yeast Saccharomycopsis lipolytica Grown on Alkanes

Abstract: SUMMARY: The intracellular concentrations of citric and isocitric acids were very low for most of the growth cycle of Saccharomycopsis lipolytica on alkanes. They increased linearly during the phase of acid excretion and the intracellular concentration was similar to the extracellular concentration (for citric acid) or a little below (for isocitric acid). The high ratios of isocitric to citric acid observed in the external medium (0.73) and in the internal pool (0.42) may be explained by compartmentalization of the metabolism of these acids which probably involves a selective transport of isocitric acid from the mitochondrion to the cytoplasm. The results suggest that acid excretion from the cytoplasm to the external medium takes place by diffusion.

Preparing beverage mix containing dextrose hydrate and coated citric acid

Abstract: A dry, free-flowing beverage mix and a process for its preparation are described. The method of preparation comprises coating the particles of a food acid with a desiccating agent and then mixing the coated food acid particles with a saccharide material and other dry beverage mix ingredients.