it can effectively protect the contents from oxidation and prolong storage period; Its transparency corresponds to animal , so that the filled contents are clearly visible; It doesn't contain animal protein and fat, so that it is hard to breed microorganism and with stable quality; it doesn't contain animal ingredients, and is free of worries for bovine spongiform encephalopathy, foot-and-mouth disease and other zoonoses; It is made by nature vegetal materials so that it is with no limit in religion or vegetarian diet. Natamycin,also known as pimaricin and sometimes sold as Natacyn, is a naturally occurring antifungal agent produced during fermentation by the bacterium Streptomyces natalensis, commonly found in soil. Natamycin has a very low solubility in water. Natamycin is a kind of natural antifungal compound produced by Streptomyces fermentation. It belongs to polyene macrolide. It can not only inhibit the growth of various molds and yeasts, but also inhibit the production of mycotoxins. It can be widely used in food preservation and antifungal treatment. Natamycin has no inhibitory effect on bacteria, so it does not affect the natural ripening process of yoghurt, cheese, raw ham and dry sausage.