Surfatech - Citric Acid
Chemistry: Citric acid or 2-hydroxy-1,2,3-propanetricarboxylic acid, is an organic carboxylic acid containing three carboxyl groups ; it is a solid at room temperature, melts at 153°C, and decomposes at higher temperatures.
Use: It is responsible for the tart taste of various fruits in which it occurs, e.g., lemons, limes, oranges, pineapples, and gooseberries. It can be extracted from the juice of citrus fruits by adding calcium oxide (lime) to form calcium citrate, an insoluble precipitate that can be collected by filtration; the citric acid can be recovered from its calcium salt by adding sulfuric acid.
Source: It is obtained also by fermentation of glucose with the aid of the mold Aspergillus niger and can be obtained synthetically from acetone or glycerol.