What is Natamycin Natamycin is a natural compound used as a natural preservative in many food products. It stops mold and yeast from growing, keeping food fresh longer. This natural preservative is key in the food world. It keeps food quality high without risking safety. With Natamycin, food makers can keep their products fresh for longer. Key Takeaways It is a natural preservative used in food products. It has antifungal properties that prevent mold and yeast growth. It extends the shelf life of food items.