Tricalcium Citrate

Introduction

The most commonly used calcium salt of citric acid is tricalcium dicitrate tetrahydrate, hereinafter referred to as tricalcium citrate. In some countries such as the USA, tricalcium citrate is simply denominated calcium citrate. It is produced by complete neutralisation of citric acid with a high purity calcium source.

With its high calcium content of 21%, tricalcium citrate is the most economic calcium salt among the commonly used organic calcium salts.

Tricalcium citrate is supplied as a white, odourless, crystalline powder or fine powder. It is slightly soluble in water and freely soluble in diluted hydrochloric acid. In contrary to other salts, tricalcium citrate is better soluble at lower temperatures (so-called ‚inverse solubility‘). It is practically insoluble in alcohol.

During heat treatment, it is less reactive than other calcium salts due to its inverse solubility. With regard to its significantly better bioavailability, tricalcium citrate is preferred over inorganic calcium sources such as calcium carbonate or calcium phosphate.

Functions

This ingredient offers you the following excellent functions.

• Bioavailability/improved mineral absorption​
• Buffering agent
• Chelating agent
• Chelation​
• Direct compression​
• Gelling
• Improved flowability​
• Increased tablet hardness​
• Mineral fortification​
• pH-Regulation​
• Phosphate replacement​
• Stabilisation
• Stabiliser
• Tablet binder
• Tablet or capsule diluent

Specifications

Tricalcium citrate is specified to meet the requirements of the latest edition of the United States Pharmacopeia (USP), the Food Chemicals Codex (FCC), and the Commission Regulation (EU) No 231/2012.

The following granulation types are available:

• Micronised powder
• Powder
• Granular

Tricalcium citrate is supplied in PE-bags, polyethylene lined paper bags and big bags. Net quantity of bags ranges from 10kg to 25kg, depending on the individual bulk density of the desired granulation. Big bag net weight is 500kg.

Legal aspects

In Europe, tricalcium citrate is listed as a generally permitted food additive (E333) and may be added to all foodstuffs, following the ‚quantum satis‘ principle as regulated in EU Regulation (EC) No 1333/2008 (Annex 2), as long as no special regulation restricts the use. In addition to existing national allowances in some countries, tricalcium citrate is on the positive list of Regulation (EC) No 1925/2006 on food fortification and is allowed in food supplements (Directive 2002/46/EC). It is listed as mineral salt in the EU Regulation (EC) No 609/2013 on food intended for infants and young children, food for special medical purposes, and total diet replacement for weight control.

The US Food and Drug Administration (FDA) affirmed tricalcium citrate as Generally Recognized as Safe (GRAS) and permitted the use in food with no limitation other than current good manufacturing practice (21CFR §184.1195).