What is natamycin, and what is its mechanism of action?
Natamycin or pimaricin appears naturally as a result of the fermentation of bacteria in the Streptomyces natalensis genus. It was discovered more than 50 years ago, and is mainly used for the preservation of food in both its liquid and powder form.
Natamycin protects food from mould and yeast growth using a mechanism that destabilises ergosterol in its cell wall. Ergosterol is responsible for the intracellular transport of nutrients and is therefore crucial for their survival. As ergosterol is not present on the outer membranes of the bacteria, they are unaffected.
Why is natamycin used?
Natamycin is one of the food preservatives permitted worldwide to protect products such as cheeses, fermented/dried sausages, yoghurts, beverages, wines, and baked goods against contamination by fungi and/or yeasts.
Thanks to natamycin’s benefits as a natural and efficient method of preserving food, its application has enormous potential to extend shelf life and prevent spoilage.
Natamycin and shelf life
The main and most extensively approved areas for the application of natamycin are cheese and dried/fermented sausages. Both food categories need preservation against fungi and yeast, but need to allow cultures (i.e. bacteria) to remain active.
It is also used in crops and as external protection for fruit against contamination by moulds and yeasts that can lead its condition to deteriorate.
Effective at low doses and stable over a wide pH range
Natamycin is stable over a wide pH range (3 to 9), which means it is highly versatile. For prevention, natamycin is very active at low doses of between 3 to 20 ppm (i.e. 3 to 20 mg/kg of the end product).
Natamycin has been approved as a food preservative suitable for human consumption by the European Food Safety Authority (EFSA), the World Health Organization (WHO) and the Food and Drug Administration (FDA).