Researchers in Brazil have found a way to preserve bread kept at room temperature for up to 15 days without growing mold, and they have done it using natural preservatives rather than chemicals.

Their report, “Edible Films from Methylcellulose and Nanoemulsions of Clove Bud (Syzygium aromaticum) and Oregano (Origanum vulgare) Essential Oils as Shelf Life Extenders for Sliced Bread,” was completed by Caio G. Otoni, Silvania F. O. Pontes, Eber A. A. Medeiros, and Nilda de F. F. Soares of the Laboratory of Food Packaging, Department of Food Technology, Federal University of Viçosa, in Brazil, and was published in the Journal of Agricultural and Food Chemistry.

natural bread preservativesThe University of Viscosa team found two ways of preserving bread, using plant-based essential oils and using natural preservatives.

Natural preservatives, such as oregano and clove–which have natural antimicrobial properties–were added to the packaging of bread to keep airborne microbes, fungi and yeast from developing into green mold on the surface of bread.

In another test, essential oils were mixed with water and a plant-based thickener and applied to the bread as an “edible film.” The bread was then placed inside a plastic bag for storage.

Both tests had similar results. Bread kept at room temperature could store bread mold free for over two weeks–rather than the usual few days.

This natural method is being proposed by the Brazilian team as an alternative to the chemicals that are usually added to fresh bread to preserve it from mold.

The team also suggested that the technique could be used on a larger scale, and are currently experimenting with using the edible films to fruits, mean products and dairy.

By Heidi Woolf