ANSWER

Natamycin is active against all known yeasts and molds but not against bacteria. This is because bacteria are insensitive to polyene antibiotics as their membrane lacks sterols (EFSA, 2009).

Nisin is extensively used to protect a wide range of food products against spoilage bacteria. It can be used in milk and milk products application such as ice cream (Baines & Seal, 2012). However, Nisin was less active against ice cream with increasing fat concentrations. This was probably due to the binding of Nisin to fat globules (Zeuthen & Bogh-Sorensen, 2003).

References

EFSA. (2009). Scientific Opinion on the use of natamycin (E 235) as a food additive. EFSA Journal, 7(12), 1412. https://doi.org/10.2903/j.efsa.2009.1412

Zeuthen, P., & Bogh-Sorensen, L. (2003). Food preservation techniques (p. 17). Cambridge: Woodhead Publising Limited.