Natamycin, also known as pimamycin or natamycin, was first isolated from Streptomyces natale in 1955 and its activity is much better than that of sorbic acid. In June 1982, the US FDA officially approved Natamycin as a food preservative.

Antibacterial mechanism
Natamycin relies on its lactone ring structure to interact with sterol compounds on the fungal cell membrane, forming antibiotic sterol compounds, thereby disrupting the structure of the fungal cell membrane. The hydrophilic part (polyol part) of macrocyclic lipids forms water pores on the membrane, damaging the permeability of the cell membrane, leading to the leakage of amino acids, electrolytes, and other substances within the bacteria, resulting in bacterial death. When certain microbial cell membranes do not contain sterol compounds, natamycin has no effect on them. Therefore, natamycin only inhibits fungi and does not have antibacterial activity against bacteria and viruses.

Scope of use of Natamycin
GB 2760-2014 National Food Safety Standard Guide for the Use of Food Additives stipulates that Natamycin can be used in 11 kinds of food, including cheese, processed cheese and its analogues, cakes, meat products with soy sauce, smoked and barbecued meat, fried meat, western ham, meat sausage, fermented meat products, mayonnaise and salad dressing, fruit and vegetable juice (pulp) and fermented wine.

Natamycin cannot be applied to foods other than the above food categories. It should be noted that in the food classification of GB 2760-2014, pastry and bread are two types of products. That is to say, natamycin cannot be used as a preservative on bread. And if natamycin is added during the bread making process, it will inhibit yeast fermentation and cause the bread to not rise.

Application of Natamycin in the Food Industry
Due to the rich nutritional content of food, it is highly susceptible to contamination by some bacteria and fungi. Some fungi also produce toxins, such as penicillic acid and aflatoxin, which pose great harm to human health. Natamycin, as a food preservative, can effectively inhibit the growth and reproduction of mold and filamentous fungi, thereby controlling some harmful toxins that contaminate food. However, Natamycin does not have an inhibitory effect on some probiotics such as sodium lactate bacteria, so it will not affect the processing, production, and flavor characteristics of fermented food.