Natamycin (CAS No.: 7681-93-8), nearly white or cream yellow crystalline powder. It is an odorless, tasteless, low-dose and highly safe food preservative. Natamycin is a white to milky white odorless and tasteless crystalline powder prepared by controlled fermentation of Streptomyces natata, usually in the form of an enol structure. Its mechanism of action is to combine with fungal ergosterol and other sterol groups to inhibit the biosynthesis of ergosterol, thereby causing cell membrane distortion, eventually leading to leakage and cell death. Surface treatment of dough with natamycin in bakery foods can significantly extend the shelf life.
Natamycin is a polyene macrolide antifungal agent with fungicidal effect. It is equally effective against yeast and mold, but has no effect on bacteria. Many countries have approved its use in various foods. For more than 50 years, natamycin has been used to extend the shelf life of various foods by eliminating yeast and mold and inhibiting the development of mycotoxins.
Natamycin kills yeasts and molds on contact, and is effective at very low levels (3-10ppm). Since natamycin is only slightly soluble in aqueous systems, it tends to stay on the surface of the food to which it is applied, so it is very effective in preventing the growth of yeast and mold on the surface of the food. On cheese, natamycin can be applied to the surface by spraying or dipping an aqueous suspension, or as part of a milky cheese coating. Natamycin does not affect the sensory quality of food, nor does it inhibit the culture of starter in fermented food.
Its medical use is now limited to the topical treatment of fungal corneal infections and the prevention of such infections in contact lens users. Natamycin is used topically in veterinary medicine to treat fungal infections, such as ringworm in cattle and horses. Previously, it was used topically to combat fungal infections of human skin and mucous membranes.