Kojic acid

Kojic Acid is a chelation agent produced by several species of fungi, especially Aspergillus oryzae, which has the Japanese common name koji. Kojic acid is a by-product in the fermentation process of malting rice, for use in the manufacturing of sake, the Japanese rice wine. It is a mild inhibitor of the formation of pigment in plant and animal tissues, and is used in food and cosmetics to preserve or change colors of substances.

Chemistry

Kojic Acid is a pyrone derivative produced from carbohydrates, particularly glucose, by fermentation. It is a white crystalline powder that is soluble in water, alcohols, and other polar solvents. The chemical name of kojic acid is 5-hydroxy-2-hydroxymethyl-4-pyrone. It has a molecular weight of 142.11 g/mol and a melting point of 153-156 °C.

Uses

Kojic acid is widely used in the cosmetics industry as a skin-lightening agent. It inhibits the activity of tyrosinase, the enzyme responsible for the production of melanin, the pigment that gives color to our skin, hair, and eyes. By inhibiting tyrosinase, kojic acid can prevent the formation of unwanted pigmentation, helping to lighten the skin.

In addition to its cosmetic applications, kojic acid is also used in the food industry as a natural preservative. It has antioxidant properties that can help to prevent the oxidation of foods, thereby extending their shelf life.

Safety and Side Effects

While kojic acid is generally considered safe for topical use, it can cause some side effects, including skin irritation and allergic contact dermatitis. It is recommended to use kojic acid-containing products in moderation and to always perform a patch test before applying them to large areas of the skin.

See Also

• Hydroquinone
• Melanin
• Tyrosinase