Topic
Citric acid
About: Citric acid is a research topic. Over the lifetime, 17745 publications have been published within this topic receiving 277125 citations. The topic is also known as: citrate & H3cit.
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TL;DR: In this paper, an anthocyanin extract was prepared by treating Concord grape filter trim with methanol acidified with 0.01% citric acid, and the extract was concentrated to provide an aqueous extract for testing as a colorant for beverages.
Abstract: An anthocyanin extract was prepared by treating Concord grape filter trim with methanol acidified with 0.01% citric acid. The extract was concentrated to provide an aqueous extract for testing as a colorant for beverages. The concentrate was freeze-dried on a dextran carrier for use with a dry beverage mix. The stability of the anthocyanins in beverages with added glucose or sucrose was not pH dependent over the range from pH 2.8—3.6. Presence of ascorbic acid increased the pigment degradation rate. 5-hydroxymethyl-Zfurfural (HMF) did not accumulate on storage in sufficient amounts to affect appreciably the degradation rate. D2 1 2 and z values were determined under aerobic conditions for several systems. The calorimetric “a/” L' function correlated well with anthocyanin content at higher storage temperatures. The pigment was very stable in carbonated beverages, jelly and dry beverage base mix.
66 citations
TL;DR: Temperature has weak influence both on pure substance and with citric acid adsorbed, as derivatographic analysis has shown, and characterization of hydroxyapatite structure may be carried out by this thermal analysis.
Abstract: The specific adsorption of citric acid ions at hydroxyapatite interface was investigated by the means of radioisotope method (14C) as a function of citric acid ions concentration, NaCl concentration and pH. Application of the hydroxyapatite has become wide in the biomaterial field as the Ca10(OH)2(PO4)6 possess biocompatibility with human hard tissue. Hydroxyapatite was synthesized using three different methods. The physical properties of the resulting powder were characterized by DTA/TG, XRD, AFM and SEM microscopy. Physicochemical qualities characterizing the electrical double layer of the hydroxyapatite/NaCl solution interface were determined. The zeta potential and the adsorption of citric acid molecule were studied as a function of pH. The point of zero charge and the isoelectric point of samples were determined. Electrical double layer parameters of hydroxyapatite/NaCl interface are influenced by a synthesis method. The points pHpzc and pHIEP for sample 1 are pHpzc 7.5 and pHIEP 3; for sample 2 pHpzc 7.05 and pHIEP 3, for smaple 3 pHpzc 6.7 and pHIEP 3. Temperature has weak influence both on pure substance and with citric acid adsorbed, as derivatographic analysis has shown, and characterization of hydroxyapatite structure may be carried out by this thermal analysis. Two phenomena are responsible for citric acid adsorption: phosphate group’s replacement at hydroxyapatite surface by citric ions parallel to intraspherical complexes formation.
66 citations
TL;DR: In this article, a chemically defined medium under anerobic conditions Lactobacillus plantarum grew on glucose, but was unable to grow with mannitol as the carbon source.
66 citations
TL;DR: In this paper, the results of soil washing and flushing experiments indicate that citric acid is highly effective in removing uranium, and that the extraction efficiency increases with increasing acid concentration, especially under slightly acidic to alkaline conditions in systems containing sand coated with secondary minerals.
Abstract: Laboratory bench-scale soil washing (batch) and flushing (column flow) experiments were conducted to determine the efficiency of citric acid as an agent to extract uranium from a synthetically contaminated sandy soil. The results of soil washing and flushing experiments indicate that citric acid is highly effective in removing uranium, and that the extraction efficiency increases with increasing citric acid concentration, especially under slightly acidic to alkaline conditions in systems containing sand coated with secondary minerals (e.g., Fe). The enhanced U(VI) desorption in the presence of citrate may be explained through several processes, including the complexation of U(VI) with citrate and extraction of secondary coatings (e.g., Fe), which results in the liberation of Fe-citrate complexes into solution. In batch washing systems, the presence of 10 -3 M citric acid enhances the extraction of uranium 2.8 times greater than water alone for the conditions of the experiment. A comparison of soil washing and flushing shows that the extraction efficiency is higher in bench-scale washing experiments. A removal efficiency of up to 98% was achieved with 10 mL of 10 -3 M citric acid in batch systems, whereas it required 4 pore volumes (150 mL) of 0.1 M citric acid to accomplish similar extraction efficiencies in column soil flushing systems.
66 citations
TL;DR: The citric acid solution did not impair cell growth and viability, proving to be noncytotoxic in vitro, and EDTA solution was evaluated comparatively the cytotoxicity of a 17%EDTA solution and that of three solutions with different concentrations ofcitric acid on cultured fibroblasts.
66 citations