It adds a taste that can be described as sour, or tart, to foods, while also acting as a preservative.
The white power on some sour candies is likely citric acid.
Citric Acid occurs naturally in many fruits and vegetables, and in the metabolism of many living things. It is most concentrated in lemons and limes, being up to 8% of their dry weight.
Most Citric Acid is produced commercially by fermentation, using a mould called “Aspergillus niger ” or yeasts (Candida guilliermondii or Candida lipolytica.)
Over half of the world’s production of Citric Acid is in China (as of 2010.) Of the world’s production, 70% is used in food and beverages, and 30% for non-food usage such as bath fizzies and bath bombs (in combination with baking soda.)
Citric Acid is not the same as ascorbic acid or Vitamin C
Hard-water stains on glasses can be removed with a solution of 6% Citric Acid (that’s about 6g of Citric Acid powder to 100ml of water.) Citric Acid powder can be purchased at your pharmacist or chemist.
A few people believe that they may have an intolerance to citric acid, though many doctors dispute that there is such a condition.
Citric Acid was first isolated in 1784. The Swedish chemist Carl Wilhelm Scheele crystallized it from lemon juice. He was also the first to isolate malic acid, in 1785.
In 1860, commercial production began in England, using calcium citrate (calcium salt of citric acid) imported from Italy.
In 1917, American food chemist James Currie discovered that certain strains of the mould Aspergillus niger can produce it as a by-product of their fermentation.
Pfizer began production of Citric Acid this way in 1919.
E number E330. The molecular formula is C6H8O7.
R.E.D. FACTS: Citric Acid. United States Environmental Protection Agency: Prevention, Pesticides And Toxic Substances. EPA-738-F-92-017. June 1992.