Food Additives: Sequestrants, Antioxidants, and Their Uses
Metal Sequestrants and Synergistic Antioxidants
These antioxidants work by sequestering trace metals like copper and iron found naturally in food or introduced during processing. These metals can accelerate oxidation reactions.
Functions of Sequestrants
Some sequestrants also act as acidifiers or preservatives. Additives with other primary functions, such as phosphates and sorbitol, can also exhibit antioxidant activity through this mechanism.
Lactic Acid and Its Salts (E-270, E-325, E-326, E-327)
Produced by microorganisms acting on milk sugar, lactic acid plays a role in blood clotting and acts as a natural preservative and acidifier in fermented products like yogurt. It’s also used in pickle production.
Industrial Production and Uses
Lactic acid is produced industrially using microorganisms like Bacillus acidi lacti and Lactobacillus bulgaricus on byproducts like whey or molasses. Flour and potatoes are also utilized.
- Used as a preservative, especially in baking.
- Acts as an acidity regulator in various products, from soft drinks to meat.
- Calcium lactate serves as a hardener in olive and vegetable production.
Safety
Lactic acid is considered safe for consumption.
Citrates (E-330, E-331, E-332, E-333, E-380)
Citric acid and its derivatives are widely used additives produced through fermentation, often involving mold growth on sugar-rich foods. Pineapple processing byproducts are also a source.
Uses
- Found in most soft drinks (excluding cola, which uses phosphoric acid).
- Used in candy, cakes, ice cream to prevent browning.
- Utilized in pickles, bread, canned fish, and other food preservation.
- Sodium or potassium citrate stabilize sterilized or UHT milk.
Safety
Citric acid is harmless.
Tartaric Acid and Tartrates (E-334, E-335, E-336, E-337, E-353, E-354)
Naturally present in fruit juices like grape juice, tartaric acid precipitates as potassium salt during winemaking. This precipitate is the primary industrial source.
Uses
- Used as a souring agent in soft drinks, enhancing fruit flavors.
- Found in sweets, candies, chewing gum, baked goods, canned vegetables, jams, and more.
- Tartaric acid and potassium sodium tartrate are components of some baking powders.
Safety
Tartaric acid is mostly unabsorbed in the intestine and considered harmless.
Calcium Disodium EDTA (E-385)
This synthetic compound is a powerful metal sequestrant.
Uses
- Approved for use in canned vegetables, fish, and frozen crustaceans and cephalopods.
- Excreted unmetabolized in urine.
Safety
Despite occasional concerns, there’s no evidence of carcinogenic effects.
Phosphates (E-338, E-339, E-340, E-341, E-343)
Derived from phosphate rock, these compounds act as metal sequestrants and antioxidants.
Uses
- Sodium and potassium phosphates are used as stabilizers in meat products, reducing water loss and increasing juiciness.
- Used in dairy products like UHT milk to prevent gelling.
- Used in processed cheese to prevent fat separation.
- Enhance dough properties and yeast growth in bread making.
- Used as processing aids in oil refining and acidity regulators.
- Some phosphates are used as gasifiers in baking powders.