TRICALCIUM PHOSPHATE

Introduction

Tricalcium Phosphate (TCP), also known as tribasic calcium phosphate or E341(iii), is a calcium salt of phosphoric acid. In the food industry, it is a versatile additive used as a free-flowing agent, anticaking agent, mineral supplement, and buffering agent. Its chemical formula is Ca₃(PO₄)₂, but commercially, it often exists in a complex, hydroxyapatite-like form.

One of its most valuable properties is its ability to absorb and retain oil while maintaining a dry powder feel. This makes it a key ingredient in dry mixes like powdered soups, spices, and baking powders. It is also a widely used source of supplemental calcium in fortified foods and beverages, valued for its high calcium content and low cost.

CAS Number

7758-87-4 (β-form)

Synonyms

• Tribasic calcium phosphate
• Calcium orthophosphate
• Hydroxyapatite (when in the form Ca₅(PO₄)₃(OH))
• Precipitated calcium phosphate
• E341(iii)
• Tertiary calcium phosphate

Topic Headings

1. Primary Food Applications (list form)

• Anticaking agent — Added to powdered and granulated foods (e.g., table salt, baking powder, powdered sugar) to absorb moisture and prevent clumping.
• Mineral supplement (calcium fortification) — Used to fortify various foods like plant-based milks, fruit juices, flour, breakfast cereals, and infant formulas.
• Dough conditioner — Improves texture and machinability in baked goods, particularly in bread and tortillas.
• Buffering agent — Helps maintain a stable pH in processed foods, which is crucial for flavor and texture.
• Yeast nutrient — Provides a source of phosphorus for yeast in baking applications.
• Polishing agent — Used in the polishing of some confectionery products.

2. Mechanism of Action as an Anticaking Agent (paragraph form)

Tricalcium phosphate prevents caking through a process of physical absorption. In its preferred fine particle form, it coats the surface of larger salt or sugar crystals. The porous structure of TCP absorbs excess moisture from the environment, thereby preventing the formation of a liquid film on the surface of the host crystals. Without this film, the crystals cannot bridge together and form hard lumps when they dry. The powder remains free-flowing.

3. Physical and chemical properties (list form)

• Appearance — White, odorless, tasteless powder.
• Molecular weight — 310.18 g/mol (for Ca₃(PO₄)₂).
• Solubility — Very low in water (approx. 0.002 g/100mL).
• pH (10% slurry) — Approximately 7.5-8.5.
• Density — Approximately 3.14 g/cm³.
• Calcium content — About 38-40% calcium by weight.
• Phosphorus content — About 20% phosphorus by weight.
• Particle size — Available in various grades, including fine powders (e.g., 30-100 mesh and F-6000 type) and granular forms.

4. Safety and Regulatory Status (paragraph form)

Tricalcium phosphate is considered a very safe and widely approved food additive. It is on the FDA's GRAS list and is permitted as a direct food additive under 21 CFR 182.8217. In the EU, it has been re-evaluated by EFSA as E341(iii) and is considered safe at current permitted levels. JECFA has established an ADI of "not limited" for phosphates from all dietary sources, as long as the total phosphorus intake is within acceptable levels. Since it is a normal component of the human diet, it is not an allergen and has no known toxic effects at typical usage levels.