Eucalyptus and Oregano Oil Thwart Fungal Disease and Preserve Fruit Longer Than Chemicals

Essential oils from oregano and eucalyptus plants could eliminate fungi that grows on and damages fruits and vegetables, researchers from the National University of Mexico (UNAM) reveal in a recent study. In turn, this could prevent certain fungal diseases from spreading among packaged produce, caused significant economic loss, according to a news release. 

For UNAM's recent study, researchers designed an oregano and eucalyptus oil-based anti-fungal to be used in fruit and vegetable packaging. Essentially, their new packaging allows a controlled release of anti-fungal compounds contained in the oils that ultimately reduce the spread of diseases during storage. This helps keep produce fresh for longer periods and safer to eat.  

"The idea is that the packaging materials incorporate the antimicrobial agent as an additional protective barrier. It is a method of preservation which extends its life and reduces the risk of transmitting pathogens to food," Trejo added.

In their tests, researchers were able to successfully control fungi such as Botrytis cinerea, Fusarium sp. and Colletotrichum sp, which are known to cause diseases in strawberries, raspberries, mangoes, papayas, tomatoes and zucchini. 

"From the encapsulation of these compounds we are looking to have a controlled release to avoid the presence of microorganisms in the fruits and vegetables. However, it will only be effective if attacked by the fungus the essential oils work against," Dr. Andrea Trejo, lead researcher, said in the release.

Oregano is a very popular herb commonly used to flavor food. Aside from culinary applications, the herb also contains antioxidants and anti-bacterial properties and is known to treat respiratory tract disorders, gastrointestinal (GI) disorders, menstrual cramps, and urinary tract disorders. Generally, oregano grows 50 cm tall and has relatively small purple leaves.

Like oregano, eucalyptus also has a distinct flavor and posses several health benefits. It's an anti-inflammatory, decongestant and has anti-bacterial properties. Eucalyptus is native to Australia and grows from the fresh leaves of tall evergreen eucalyptus trees, which are also referred to as a fever tree, blue gum tree or stringy bark tree, depending on where it grows.

The only drawback to this preservation method involves the plants' distinct flavors, which alter the taste of produce.  Currently, researchers are evaluating the use of other less flavorful plant products.