Citric Acid

About This Product

Citric acid is the most widely used food acidulant and is authorised as additive E330 in the EU and UK. It is supplied in two crystalline forms: anhydrous citric acid (CAS 77-92-9, C6H8O7, 192.12 g/mol) and citric acid monohydrate (CAS 5949-29-1, C6H8O7·H2O, 210.14 g/mol). Both are white, odourless crystals with a clean, sharp, fruity sourness, produced commercially by fermentation of carbohydrate followed by purification and crystallisation. Each form is offered in granular, fine granular and powder grades.

Citric acid lowers pH, adds sourness and chelates trace metals, which slows oxidation and supports antioxidants such as ascorbic acid and tocopherols. It is used in carbonated and still soft drinks, juice drinks and squashes, sugar and gelatine confectionery, sour sanding, jams and fruit preparations where it sets the pH for pectin gelling, sauces and dressings, canned fruit and vegetables, frozen fruit, dairy desserts and effervescent products. The dose is set by the target pH and sourness rather than a fixed rate; soft drinks typically contain around 0.1 % to 0.3 %, and high-methoxyl pectin jams are adjusted to roughly pH 3.0 to 3.3.

The choice of form is practical. Anhydrous citric acid is preferred for dry mixes, powdered drinks, effervescent tablets and confectionery sanding, because water from the monohydrate can cause caking or premature reaction with bicarbonates. Monohydrate is widely used in liquid applications. When switching, 1 kg of anhydrous equals about 1.094 kg of monohydrate. Particle size matters in dry blends: fine granular grades mix evenly with powders, while coarser granules flow and dissolve without dusting. Sodium citrate is often added alongside to buffer pH and soften the sourness.

Typical specification points are the form and assay (calculated on the anhydrous basis), water content, particle-size range or mesh, sulphated ash, oxalate, sulphate, lead and readily carbonisable substances, together with conformity to the E330 purity criteria in Regulation (EU) No 231/2012 and its GB equivalent. Where an export market or a pharmaceutical application requires it, specify the FCC, JECFA or relevant pharmacopoeia monograph.

Citric acid is authorised in a wide range of food categories, often at quantum satis, but not everywhere, and some categories restrict acids. Check Annex II of Regulation (EC) No 1333/2008 and the UK retained equivalent for your product. It is declared as acid: citric acid, or as acidity regulator where that is its function, or by its E-number. It is not classed as a preservative, although lowering pH makes preservatives more effective.

Store sealed bags in a cool, dry place with a stable temperature; humidity and temperature cycling cause caking, especially with monohydrate. The dust irritates eyes, so use eye protection and dust control. Keep it away from carbonates and bicarbonates, and check that tanks and dosing lines resist concentrated acid solutions. When you enquire, specify anhydrous or monohydrate, the mesh or particle range, the purity standard, pack size, annual volume and destination, and the documents you need.