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.

Citric acid production from whey with sugars and additives by Aspergillus niger

Abstract: Citric acid (CA) production by Aspergillus niger ATCC9642 from whey with different concentrations of sucrose, glucose, fructose, galactose riboflavin, tricalcium phosphate and methanol in surface culture process was studied. It was found that whey with 15% (w/v) sucrose with or without 1% methanol was the most favourable medium producing the highest amount (106.5 g/l) of citric acid. Lower CA was produced from whey with other concentrations of sugars and other additives used. Highest biomass ofA. niger was produced with the addition of riboflavins. In general, extension of the fermentation (up to 20 days) resulted in an increase in CA and biomass, and decrease in both residual sucrose and pH values. Key words: Citric acid, Aspergillus niger, whey fermentation, surface culture.

Composition of natural antioxidants for the stabilization of polyunsaturated oils

Abstract: The present invention provides for a composition of natural antioudants comprising tocopherol, ascorbic acid, citric acid and phospholepeds which are useful in oxidation of oils.

Solution Combustion Synthesis and Characterization of Magnetite, Fe3O4, Nanopowders

Abstract: Combustion synthesis of Fe3O4 and properties of the resulted powders have been discussed in relation to reaction atmosphere (in air/in the absence of air) and used fuel (sucrose, citric acid and glucose). Conducting the combustion reactions in air caused the rapid oxidation of Fe2+ to Fe3+ under the influence of the atmospheric oxygen; therefore the final reaction product was a mixture of α-Fe2O3 and γ-Fe2O3. In order to avoid the oxidation of Fe2+ to Fe3+ a simple but efficient solution has been suggested: combustion reactions were carried out in a round bottom flask and the evolving gases were bubbled in a beaker filled with water. This solution allowed the preparation of Fe3O4 nanopowders, with crystallite size varying from 10 nm (glucose) to 18 nm (citric acid). Depending on the used fuel, the specific surface area of the magnetite powders varied between 56 m2/g (citric acid) and 106 m2/g (glucose). The saturation magnetization of Fe3O4 powders prepared in the absence of air ranged between 55.3 emu/g (glucose) and 59.4 emu/g (sucrose).

Study of the organic acids composition of quince (Cydonia oblonga Miller) fruit and jam.

Abstract: The organic acids present in several samples of quince fruit (pulp and peel) and quince jam (homemade and industrially manufactured) were analyzed by HPLC. The sample preparation was simple, involving only extraction with methanol (40 degrees C) and filtration through a Sep-pack C18 cartridge. The chromatographic separation was achieved using an ion exclusion column, Nucleogel Ion 300 OA (300 x 7.7 mm), in conjunction with a column heating device at 30 degrees C. An isocratic elution with H(2)SO(4) 0.01 N as the mobile phase, with a flow rate of 0.1 mL/min, and UV detection at 214 nm were used. These analyses showed that all samples presented a similar profile composed of at least six identified organic acids: citric, ascorbic, malic, quinic, shikimic, and fumaric acids. Several samples also contained oxalic acid. This study suggests that the organic acids levels and ratios may be useful for the determination of percent fruit content of quince jams. The citric acid value can also be used in the differentiation of the type of manufacture of the commercial quince jams (homemade or industrially manufactured).