E234 - Nisin

Origin

Nisin is a polycyclic antibacterial peptide produced by certain strains of *Lactococcus lactis*. It is a naturally occurring antimicrobial substance, specifically a bacteriocin, which means it is a protein produced by bacteria to inhibit the growth of other bacteria. Commercial nisin is typically produced by fermentation of *L. lactis* strains in a suitable medium, followed by extraction and purification.

Usage

Nisin is primarily used as a food preservative, particularly effective against Gram-positive bacteria, including *Bacillus* and *Clostridium* species, which are common causes of spoilage in processed foods. It is widely used in the dairy industry to prevent spoilage in cheese, processed cheese products, and dairy desserts. Nisin can also be found in canned goods, processed meats, and beverages to extend shelf life and prevent the growth of spoilage organisms and pathogens. Its effectiveness is pH-dependent, working best in acidic conditions. The typical usage levels range from 3 to 25 ppm, depending on the food product and the target microorganisms.

Side Effects

Nisin is generally considered safe for consumption. It is rapidly digested in the small intestine by proteases, breaking it down into amino acids. Due to this rapid degradation, nisin is unlikely to cause systemic toxicity or allergic reactions. Extensive toxicological studies have not revealed any significant adverse effects at levels used in food. However, as with any food additive, some individuals may exhibit sensitivity. No ADI (Acceptable Daily Intake) has been specified by JECFA or EFSA, indicating its low toxicity. While rare, hypersensitivity reactions are theoretically possible, though not well-documented.