New antimicrobial coating lets cheese last longer

Researchers have developed an edible coating with antimicrobial capacity that can increase the lifespan of cheese.
Researchers at the Universitat Politecnica de Valencia (UPV) in Spain have developed the new coating to apply to soft cheese.
These films incorporate oregano and rosemary essential oils as antimicrobial agents, and chitosan, a by-product that comes from crustacean shells.
According to Chelo Gonzalez, a researcher at the Institute of Food Engineering for Development of the UPV, the lifespan of commercial soft cheese treated with pimaricin is about 21 days in cold storage.
"The most common causes of deterioration are excessive surface dehydration and the growth of micro-organisms such as fungus or yeasts, which produce a strange flavour or odour, a slimy texture and a significant visual alteration," said Gonzalez.

The edible coating can act as an alternative to pimaricin and polyvinyl, commonly used on commercial cheese.

Another possible application in mature cheese is to decrease the growth of fungus on the surface of the cheese during the maturing process, which can enter into the pieces when they have pressing faults or fissures.
"In this case, applying the coatings that we have developed will reduce the proportion of product losses in the cheese factories and therefore the important economic losses that this implies," researchers said.
Of the oils the study used, oregano oil was the most effective, inhibiting the fungal growth in a similar way to a conventional pimaricin treatment, researchers said.

The study will be published in the International Journal of Food Studies.