Preserving bread longer: A new edible film made with essential oils

Jun 04, 2014
Preserving bread longer: A new edible film made with essential oils

Essential oils have boomed in popularity as more people seek out alternatives to replace their synthetic cleaning products, anti-mosquito sprays and medicines. Now scientists are tapping them as candidates to preserve food in a more consumer-friendly way. A study from ACS' Journal of Agricultural and Food Chemistry reports the development of new edible films containing oils from clove and oregano that preserve bread longer than commercial additives.

Nilda de F. F. Soares and colleagues note that the search for new ways to keep packaged food from spoiling has led some scientists to , which can keep bacteria and mold at bay. Oils from clove and oregano had already been incorporated into . But scientists still needed to optimize the effectiveness of these films and test them under real-life conditions for other uses. So Soares's team decided to test how well different edible films with clove and oregano essential oils could maintain bread's freshness and see how they measured up against a commercial antimicrobial agent. Bread is a common staple around the world and is often kept fresh with calcium propionate. Though naturally occurring, some research suggesting negative side effects have tarnished its popularity.

The scientists bought preservative-free bread and placed slices in plastic bags with or without essential oil-infused edible films. To some slices, they added a commercial preservative containing calcium propionate.

After 10 days, the latter additive lost its effectiveness, but the edible films made with small droplets of the continued to slow mold growth.

Explore further: Antimicrobial edible films inhibit pathogens in meat

More information: "Edible Films from Methylcellulose and Nanoemulsions of Clove Bud (Syzygium aromaticum) and Oregano (Origanum vulgare) Essential Oils as Shelf Life Extenders for Sliced Bread" J. Agric. Food Chem., 2014, 62 (22), pp 5214–5219. DOI: 10.1021/jf501055f

Abstract
Consumers are increasingly demanding foods with lower synthetic preservatives. Plant essential oils are natural compounds with remarkable antimicrobial properties and may be incorporated as emulsions into water-soluble polymers to form antimicrobial films. Coarse emulsions (diameters of 1.3–1.9 μm) and nanoemulsions (diameters of 180–250 nm) of clove bud (Syzygium aromaticum) and oregano (Origanum vulgare) essential oils were produced through low-speed mixing and ultrasonication, respectively. Methylcellulose was added for film-forming purposes. Both essential oils reduced the rigidity and increased the extensibility of the methylcellulose films, effects that were even more pronounced for nanodroplets. Both essential oils lessened the counts of yeasts and molds in sliced bread during 15 days, and droplet size reduction provided a further improvement in antimicrobial properties. Due to increased bioavailability, less preservative content might be used and still deliver the same antimicrobial efficiency if encapsulated in smaller particles.

add to favorites email to friend print save as pdf

Related Stories

Antimicrobial edible films inhibit pathogens in meat

May 01, 2014

Antimicrobial agents incorporated into edible films applied to foods to seal in flavor, freshness and color can improve the microbiological safety of meats, according to researchers in Penn State's College ...

Oregano oil may help sunflower seeds keep longer

Dec 13, 2013

Sunflower seeds and sunflower oils have been shown to decrease risk of cardiovascular disease as well as have potential beneficial effects on obesity, bone health, and blood pressure. However their high protein and fat content ...

Edible flowers may inhibit chronic diseases

Apr 21, 2014

A new study in the Journal of Food Science, published by the Institute of Food Technologists (IFT), found that common edible flowers in China are rich in phenolics and have excellent antioxidant capacity.

Edible films to kill E. coli on tap

Aug 30, 2007

Scientists at New Jersey's Rutgers University and in other labs are developing edible films and powders that kill E.coli and Salmonella.

Edible coatings for ready-to-eat fresh fruits and vegetables

Sep 10, 2013

The scientist who turned fresh-cut apple slices into a popular convenience food, available ready-to-eat in grocery stores, school cafeterias and fast-food restaurants, today described advances in keeping other foods fresh, ...

Recommended for you

Smartgels are thicker than water

Sep 19, 2014

Transforming substances from liquids into gels plays an important role across many industries, including cosmetics, medicine, and energy. But the transformation process, called gelation, where manufacturers ...

Separation of para and ortho water

Sep 18, 2014

(Phys.org) —Not all water is equal—at least not at the molecular level. There are two versions of the water molecule, para and ortho water, in which the spin states of the hydrogen nuclei are different. ...

User comments : 0