Citric Acid

Citric Acid An acidurant and antioxidant produced by mold fermentation of sugar solution and by extraction from lemon juice, limejuice, and pineapple canning residue. It is the predominant acid in oranges, lemons, and limes. It exists in anhydrous and monohydrate forms. The anhydrous from is crystallized in hot solutions and the monohydrous from is crystallized from cold (below 36.5° C) solutions. Anhydrous citric acid has a solubility of 146 g and monohydrate citric acid has a solubility of 175 g per 100 ml of distilled water at 20 ° C. A 1 percent solution has a pH of 2.3 at 25 ° C. It is a hygroscopic, strong acid of tart flavor. It is used as an acidurant in fruit drinks and carbonated beverages at 0.25 to 0.40 percent, in cheese at 3 to 4 percent, and in jellies. It is used as an antioxidant in instant potatoes, wheat chips, and potatoes sticks, where it prevents spoilage by trapping the metal ions. It is used in combination with antioxidants in the processing of fresh frozen fruits to prevent discoloration.