Olive and Grape Extracts Work Better as Food Preservatives than Synthetic Antioxidants

Email this article to a friend

Printable Version

Articles Related to This Article: • The Honest Food Guide empowers consumers with independent information about foods and health • Interview with "Kevala" Karen Parker, master raw foods chef • Cigarettes, Lies, and Pet Food Advertising NaturalNews Store Specials: • Raw organic Vanilla powder at 40% off • SunWarrior Ormus Greens at 20% off (3-pack) • Revolutionary new Hurom Slow Juicer at the lowest price on the 'net + FREE shipping! • Certified Organic Nutiva Hemp Seeds at a huge discount (+ FREE bottle of hemp oil) See more at the NN store...

(NaturalNews) Olive and grape extracts derived as byproducts of oil and wine manufacturing proved to be more effective food preservatives than pure antioxidant chemicals in a new study conducted by Portuguese researchers and published in the journal "Innovative Food Science and Emerging Technologies."

"We can assume that the natural extracts grape extract and olive extract are promising natural preservatives, with application in food industry," lead author Ana Teresa Serra said.

Researchers derived the extracts from the residue left behind as a byproduct of pressing grapes for wine and olives for olive oil. These extracts, along with three antioxidant chemicals, were tested against three bacteria species and two yeast species. The bacteria were E. coli, S. Poona, and B. cereus, while the yeasts were S. cerevisiae and C. albicans.

The three antioxidants tested were quercetin, hydroxytyrosol and oleuropein.

Of the five substances tested, the grape extract proved most effective. It inhibited growth among all three species of bacteria, with inhibition increasing along with the dose applied. Quercetin also suppressed all three bacteria species, although not as effectively as grape extract.

Olive extract, hydroxytyrosol and oleuropein were less effective still. Olive extract proved more effective against Gram–positive bacteria than Gram-negative bacteria.

Both olive and grape extracts suppressed the yeast species more effectively than quercetin or hydroxytyrosol at similar concentrations. The suppressing effects of the extracts against the yeasts were also dose-dependent.

While quercetin, hydroxytyrosol and oleuropein are all naturally occurring antioxidants, the higher effectiveness of the extracts suggests that antioxidants are not as effective when isolated from the other plant components they occur with. The researchers hypothesized that the extracts might be more effective because of "a positive synergetic effect within the constituents of grape extract, that reinforce the response and/or, the presence of other components in the matrices with antimicrobial activity."

Share

Get articles like this delivered to you FREE in our popular email newsletter

Related CounterThink Cartoons:

Related Articles: • The Honest Food Guide empowers consumers with independent information about foods and health • Interview with "Kevala" Karen Parker, master raw foods chef • Cigarettes, Lies, and Pet Food Advertising	Take Action: Support NaturalNews.com Email this article to a friend Share this article on: NewsVine | digg | del.icio.us Permalink to this article: http://www.NaturalNews.com/023328_food_food_preservatives_bacteria.html Reprinting this article: Non-commercial use OK, cite NaturalNews.com with clickable link. Embed article link: (copy HTML code below): <a href = "http://www.NaturalNews.com/023328_food_food_preservatives_bacteria.html">Olive and Grape Extracts Work Better as Food Preservatives than Synthetic Antioxidants</a>