Citric acid NEW

Citric Acid: Overview & Uses

Citric acid is a weak organic acid with the chemical formula C₆H₈O₇. It is a natural preservative and a key metabolic intermediate in the citric acid cycle (Krebs cycle) in all aerobic organisms.

• Natural Source: Predominantly found in citrus fruits (lemons, limes, oranges), giving them their characteristic sour taste.

  Commercial Production: Primarily produced via the industrial fermentation of carbohydrate solutions (often from molasses) by the mold Aspergillus niger.

  Key Properties: It is a strong chelating agent (binds to metals), acts as a natural preservative (acidulant), and provides a pleasant, sharp sourness.

Primary Uses & Applications

Citric acid is one of the most versatile and widely used food additives and industrial chemicals.

1. Food & Beverage Industry (Primary Use: ~70% of production)

• Acidulant & Flavor Enhancer: Provides tartness to soft drinks, candies, jams, jellies, and fruit-flavored products (E330 in the EU).

  Preservative: Lowers pH to inhibit the growth of bacteria and molds in canned foods, sauces, and preserves.

  Antioxidant Synergist: Enhances the effect of antioxidants in oils and fats.

  Emulsifier: Helps keep fats dispersed in processed cheeses and ice creams.

  Leavening Agent: In baking powders, it reacts with bicarbonates to produce carbon dioxide gas.

2. Pharmaceutical & Personal Care

• Effervescent: Key ingredient in effervescent tablets and powders (e.g., for vitamins or pain relief).

  Anticoagulant: Used as a chelating agent in blood collection tubes to prevent clotting by binding calcium.

  Cosmetics & Toiletries: Acts as an acidifier, antioxidant, and preservative in creams, gels, and shampoos. Used in skincare for its mild exfoliating properties.

3. Household & Industrial Cleaners

• Descaling Agent: Effectively removes limescale and rust from kettles, boilers, and coffee makers due to its chelating power. A key ingredient in eco-friendly cleaning products.

  Detergent Booster: Used in phosphate-free detergents and dishwashing powders to soften water and improve surfactant efficiency.

4. Other Technical Applications

• Water Softening: In soaps and detergents.

  Photography & Textiles: As a pH adjuster in developing baths and dyeing processes.

  Concrete Retarder: Slows the setting of cement.

Safety & Summary

Citric acid is "Generally Recognized As Safe" (GRAS). While safe in food, the pure powder or highly concentrated solutions can irritate eyes and skin. It is a cornerstone of modern industry due to its multifunctionality, effectiveness, biodegradability, and low cost.