Food preservatives, properly explained.

Sorbic acid works by penetrating microbial cell membranes in its undissociated (protonated) form.

In water-based food environments with a pH below about 6.5, potassium sorbate releases sorbic acid.

Sorbates work by disrupting the ability of mould, yeast, and some bacteria to grow.

It disrupts microbial cell membranes and interferes with essential enzyme systems, preventing mould, yeast and bacterial growth in food and beverages.

Benzoic acid works by crossing into microbial cells in its undissociated (uncharged) form.

It is bacteriostatic and fungistatic in acidic conditions: as the food's acidity lets it enter microbial cells, it lowers the internal pH and stalls the energy production bacteria, yeasts and moulds need to grow.

Benzoate ions disrupt the internal pH regulation of microbial cells, preventing mould, yeast and many bacteria from growing.

Benzoic acid, once released from calcium benzoate in water, moves into microbial cells and disrupts their internal pH, blocking the enzymes they need to produce energy.

Ethylparaben disrupts the cell membranes of bacteria, yeasts and moulds, preventing them from growing and extending the shelf life of food.

Disrupts the cell membranes of bacteria, yeasts and moulds and interferes with their enzyme activity, halting their ability to reproduce.

It works by disrupting the cell membranes of bacteria, moulds and yeasts, preventing them from growing and extending shelf life.

Inhibits the growth of moulds and yeasts by disrupting their cell membranes and interfering with enzyme function.

Methylparaben disrupts the cell membranes of bacteria, moulds and yeasts, preventing them from reproducing.

It works by damaging the outer membrane of microbes, which kills them and slows spoilage.

It works on two fronts.

It acts as a preservative and antioxidant by releasing sulphur dioxide, which inhibits the enzymes that cause browning and kills spoilage bacteria, yeasts and moulds.

Sulphur dioxide released by E222 acts as both an antimicrobial agent and an antioxidant.

Releases sulphur dioxide, which inhibits bacteria, yeasts and moulds and blocks the enzymes responsible for enzymatic browning.

The released sulphur dioxide inhibits the growth of bacteria, yeasts and moulds by disrupting their cellular processes.

Sulphites inhibit microbial growth by disrupting enzyme activity in bacteria, moulds and yeasts.

When calcium sulphite releases sulphur dioxide in food, that gas inhibits the enzymes bacteria and moulds need to reproduce, preventing spoilage.

It preserves food by releasing sulphur dioxide, which kills or slows the growth of bacteria, yeasts, and moulds.

It releases sulphur dioxide, which kills or suppresses bacteria, moulds and yeasts.

Biphenyl inhibits the growth of Penicillium mould and other fungi on the outer peel of citrus fruit during long-distance transport and cold storage.

It kills or inhibits mould fungi and bacteria by disrupting cell membranes.

It works as an antifungal agent by disrupting the cell membranes of mould fungi, particularly Penicillium species that cause green and blue rot on citrus during storage and transport.

Applied to the surface of fruit after harvest, thiabendazole disrupts fungal cell division by interfering with tubulin polymerisation, preventing moulds from forming and extending shelf life during long-distance shipping and cold storage.

Nisin targets a molecule called Lipid II, which Gram-positive bacteria need to build their cell walls.

Natamycin binds irreversibly to ergosterol, a sterol found in fungal cell membranes but absent from bacterial and human cells.

In preservation applications, formic acid inhibits the growth of bacteria, yeasts and moulds by penetrating microbial cell membranes and lowering intracellular pH, disrupting vital enzyme processes.

Acts as a preservative by creating mildly acidic conditions and releasing formate ions that inhibit the growth of bacteria, moulds and yeasts.

As a preservative it works by acidifying its environment, lowering pH enough to inhibit the growth of bacteria, moulds and yeasts.

Under acidic conditions or heat, hexamethylene tetramine breaks down and releases formaldehyde.

This entry is filed under food preservatives in our published E-number A to Z.

It kills or suppresses the growth of a broad range of bacteria, yeasts and moulds by inserting itself into their cell membranes and disrupting the membrane structure, causing the cells to lose their contents and die.

Nitrite ions released from potassium nitrite bind to the myoglobin in meat, producing the stable pink or red colour associated with cured products.

Nitrite ions released from sodium nitrite react with the myoglobin in meat to produce stable nitrosomyoglobin, giving cured products such as bacon and ham their characteristic pink or red colour.

In cured meat, sodium nitrate is reduced to sodium nitrite (E250) over time by bacteria and reducing agents.

In cured meats, bacteria reduce potassium nitrate to nitrite over the course of slow curing.

Propionate lowers the pH of baked goods and creates conditions that inhibit the growth of mould and certain bacteria, particularly rope-forming Bacillus species that cause bread to become stringy and inedible.

It releases propionic acid in food, which lowers the pH inside mould and bacterial cells, blocking the fatty acid synthesis they need to reproduce.

Inhibits the growth of moulds and certain bacteria by disrupting their ability to take up nutrients and reproduce.

Propionic acid disrupts the cell membranes and enzyme systems of mould and certain bacteria, preventing them from reproducing.

It inhibits mould, yeast and bacterial growth by disrupting microbial enzyme function.

Borax inhibits the growth of bacteria, yeasts and moulds, making it effective as a preservative.

Lysozyme kills bacteria by attacking a key structural component of their cell walls, causing the cells to burst.