Natamycin is an antifungal food preservative .It inhabits the  growth of molds andyeasts and at the same time the production of mycotoxins. Comercial Natamycin products contain 50%natamycin .It will be able to advoid food spoilage cased by various molds and yeastat a small disage of natamycin . But it does not affect the growth of bacteria used in the production of yogurt,cheese,fermented ham and sausage.Therefore the fermentation process of these products are not affected by the addition of natamycin