Definition

1. Noun:
   • A weak, water-soluble organic acid: A naturally occurring compound with a sour taste, found in high concentrations in many fruits, particularly citrus fruits like lemons, limes, oranges, and grapefruits. It is a key intermediate in the metabolic cycle of living organisms.
   • A commercial additive: A widely used substance in the food and beverage industry as an acidulant, flavoring agent, and preservative. It is also used in cleaning products, cosmetics, and pharmaceuticals.

Usage Examples

• Noun:
  • The tartness of a lemon comes primarily from citric acid.
  • This soft drink contains citric acid to enhance its flavor and act as a preservative.
  • Scientists study the role of citric acid in cellular energy production.

Advanced Usage

• In Biochemistry: Refers specifically to the compound involved in the citric acid cycle (also known as the Krebs cycle or TCA cycle), a central metabolic pathway in all aerobic organisms for generating energy.
  • The citric acid cycle is fundamental to cellular respiration.
• In Cleaning: Used for its chelating properties to bind minerals and its effectiveness as a descaling agent.
  • A solution of citric acid can be used to remove limescale from kettles.

Variants and Related Words

• Citrate (noun): A salt or ester of citric acid.
  • Potassium citrate is sometimes used as a dietary supplement.
• Citric (adjective): Pertaining to or derived from citric acid or citrus fruits.
  • The recipe calls for a citric flavor profile.

Synonyms

• E330: Its code as a food additive.
• 2-Hydroxypropane-1,2,3-tricarboxylic acid: Its systematic IUPAC chemical name.

Related Phrases/Compounds

• Citric acid cycle: The series of chemical reactions used by all aerobic organisms to release stored energy.
• Citric acid solution: A common preparation for culinary or cleaning purposes.

Noun

1. a weak water-soluble acid found in many fruits (especially citrus fruits); used as a flavoring agent