Citricacid is a weak organic acid that occurs naturally in citrus fruits. The dominant use of citricacid is as a flavoring and preservative in food and beverages, especially soft drinks and candies. Citricacid can be added to ice cream as an emulsifying agent to keep fats from separating, to caramel to prevent sucrose crystallization, or in recipes in place of fresh lemon juice. Citricacid is used with sodium bicarbonate in a wide range of effervescent formulae, both for ingestion (e.g., powders and tablets) and for personal care (e.g., bath salts, bath bombs, and cleaning of grease). It has used in culinary applications, as an alternative to vinegar or lemon juice, where a pure acid is needed.
Citricacid is an excellent chelating agent, binding metals by making them soluble. It is used to remove and discourage the buildup of limescale from boilers and evaporators. It can be used to treat water, which makes it useful in improving the effectiveness of soaps and laundry detergents. By chelating the metals in hard water, it lets these cleaners produce foam and work better without the need for water softening. Citricacid is the active ingredient in some bathroom and kitchen cleaning solutions. A solution with a six percent concentration of citricacid will remove hard water stains from glass without scrubbing. Citricacid can be used in shampoo to wash out wax and coloring from the hair.
In industry, it is used to dissolve rust from steel and passivate stainless steel.
