While the application of natamycin in Europe is limited to cheese and dried sausages, it is widely used in America, e.g. in the bakery sector in the United States, Argentina and Mexico.
Like cheese and cold cuts, bread is a product that is consumed over several days, on successive occasions, and kept at room temperature. The storage of bread before consumption is a sensitive period in terms of contamination.
Sandwich bread is a variety particularly prone to spoiling due to moulds and yeasts.
Natamycin has proven to be an effective preservative for this type of bread, since it lengthens the product’s life by up to three days.
When applied directly in the kneading phase, natamycin interferes with the main fermentation of the yeast, which means it is not advisable.
Furthermore, if it is applied directly onto the bread, a larger dose is required than when it is sprayed, and as such the latter application technique is more recommendable.
Natamycin does not affect either the texture or the firmness of bread when it is applied by spraying.
It has also been shown not to affect the smell or taste of the bread, provided that the application dose is correct.
The advantages mentioned above have been confirmed in a comparison between natamycin and potassium sorbate.
Methods to prevent contamination of bread
Natamycin is permitted in Mexico according to the Official Mexican Standard for bread made after baking.
In the United States, natamycin can be added directly to the dough of tortillas before they are placed in the oven. This is because this dough does not contain any yeast, and so it does not affect the main fermentation.
In the European Union, the traditional preservative for bread is calcium propionate (E282) – which prevents mould from growing on bread and baked foodstuffs. Radiation of bread with UV is also permitted.