Calcium benzoate refers to the calcium salt of benzoic acid. It is the calcium salt of benzoic acid and is used primarily as a preservative in food and cosmetics due to its antimicrobial properties. It is also used in various industrial applications such as in the preparation of certain types of plastics and as an additive in some lubricants.
When used in the food industry as a preservative, its E number is E213 (INS number 213); it is approved for use as a food additive in the EU, USA and Australia and New Zealand. The formulas and structures of calcium carboxylate derivatives of calcium and related metals are complex. Generally the coordination number is eight and the carboxylates form Ca-O bonds. Another variable is the degree of hydration.
Properties
- Chemical formula: Ca(C7H5O2)2
- Molar mass: 282.31 g/mol
- Solubility in water: 2.32 g/100 mL (0 °C), 8.7 g/100 mL (100 °C)
- Appearance: It is a white crystalline powder or solid.
- Stability: It is generally stable under normal conditions but may decompose when exposed to excessive heat or in the presence of strong acids or bases.
- Melting Point: The melting point of calcium benzoate is typically around 240-250°C.
- Reactivity: It can undergo reactions typical of benzoate salts, such as ion exchange reactions in the presence of acids or bases.
Occurrences
- Naturally Occurring Compounds: While calcium benzoate itself is not found naturally in large quantities, benzoic acid (the source of the benzoate ion) occurs naturally in berries, cinnamon, and other plants.
- Synthetic Production: Calcium benzoate is typically synthesized by reacting benzoic acid or sodium benzoate with calcium hydroxide (Ca(OH)₂) in aqueous solutions.
Uses
- It is preferentially used more than other benzoic acid salts or its esters in foods due to its better solubility and safety to humans.
- It is used in soft drinks, fruit juice, concentrates, soy milk, soy sauce and vinegar.
- It is the most widely used preservative in making bread and other bakery products.
- It is used as preservative for water based insecticidal composition which can be sprayed as well as in preparation of calcium formate direct sprayable fertilizers.
- It is used as preservative for mouth wash compositions.
- It is used in water hardness reducers.
Environmental Impact
Biodegradability: Calcium benzoate, like many benzoate derivatives, is relatively biodegradable, though the exact rate can depend on environmental conditions. In large quantities, it might still pose an ecological risk.
