Citric acid anhydrous, known as the water-free form of citric acid, is a white, odorless crystalline compound with the chemical formula C₆H₈O₇. With a molar mass of 192.12 g/mol, this compound contains no water molecules in its structure. Notable physical properties include a density of 1.665 g/cm³, a melting point of 156°C, and a boiling point of 310°C .

Production Method and Chemical Properties

Anhydrous citric acid is produced by crystallizing hot solutions of citric acid monohydrate or by heating the monohydrate form at 78°C. Due to the absence of water molecules, this form exhibits greater thermal stability than the hydrated variant and is preferred in industries requiring controlled solubility.

Citric acid, also known as "sour salt" or "lemon acid", is a weak organic acid with the chemical formula C₆H₈O₇. It exists in two forms: anhydrous (dry) and monohydrate (hydrated), each with distinct characteristics. The anhydrous form, lacking water molecules, appears as a white crystalline powder with a melting point of 156°C, while the monohydrate form contains one molecule of crystallization water and has a slightly higher molecular weight.

Broad Applications in the Food Industry

In the food industry, citric acid is widely used as a multi-purpose additive identified by the code E330. It functions as an acidity regulator, flavor enhancer, and natural preservative in products such as soft drinks, fruit juices, candies, and dairy items. Its antioxidant properties help prevent discoloration and spoilage of food. In cheese production, it acts as a coagulating agent, and in confectionery, it improves texture and shelf life.

Applications in Pharmaceuticals and Cosmetics

In the pharmaceutical industry, citric acid is used in the production of effervescent tablets and dietary supplements. In cosmetic and personal care products, it serves as a pH regulator, skin brightening agent, and a chelating agent for heavy metals. Its mild exfoliating property makes it beneficial in formulations for acne and blemish treatments.

Industrial and Agricultural Uses

In the detergent industry, citric acid serves as an eco-friendly alternative to phosphates. In agriculture, it is used to adjust soil pH and enhance nutrient uptake by plants. Its chelating ability also makes it useful in irrigation systems. In the oil industry, it is employed in well acidizing, and in textile manufacturing, it helps regulate pH during the dyeing process.