Wine Kills Several Types of Foodborne Pathogens
|Wine drinking gets
another boost--researchers find that it has antimicrobial
activity. (Photo © Fred Lyons/Cole Group/Getty Images.)
Folk advice that wine with raw oysters wards off food poisoning may
have merit. Mark Daeschel, a microbiologist and food scientist at Oregon
State University in Corvallis, who plans to develop a marketable
disinfectant based on the antibacterial properties of wine. He notes
that wine already is widely praised for its heart-healthy antioxidants.
Former graduate student Jessica Just and Daeschel tested wines
against bacterial pathogens such as Escherichia coli O157 or Salmonella
enterica serovar Typhimurium in a model stomach system, which
consists of a bag containing otherwise sterile synthetic gastric fluids
and food materials. Within 60 minutes after adding either a chardonnay
(white) or pinot noir (red) wine to the mix, E. coli was
inactivated. Under similar conditions, Salmonella was inactivated
within 10 to 30 minutes. Other experiments indicate that such wines also
kill Staphylococcus aureus, Pseudomonas aeruginosa, and Klebsiella
pneumoniae. A report of this study is scheduled to appear in the Journal
of Food Science later this year.
Several components in wine that are not present in grape juice appear
essential for the antibacterial activity. For example, the same bacteria
survived for up to 16 days in unfermented juice from the same chardonnay
or pinot noir grapes. To further identify the active ingredients, the
researchers distilled the wines into nonvolatile fractions containing
acids and volatile fractions containing alcohol. The acid fractions kill
bacteria faster and more efficiently than do the alcohol-containing
fractions, and the chardonnay acid fraction kills bacteria better than
does the pinot noir acid fraction.
These results suggest that the antimicrobial activity of wine depends
more on its acids (mainly malic and tartaric) than alcohol content. In
general, ``white wines are more acidic than red wines,'' says Daeschel.
The findings also suggest that people who drink wine with meals may
protect themselves from food poisoning.
Daeschel is seeking funds to harness wine's antimicrobial
capabilities. He and undergraduate student Joy Waite formulated a
wine-based spray disinfectant and tested it on pieces of Formica coated
with the nonpathogenic test organism Pediococcus pentosaceus.
Their experimental disinfectant kills these bacteria as well as does a
commercial cleaner containing hydrogen peroxide. A wine-based
disinfectant could offer consumers a biodegradable, natural alternative
that is environmentally safe--so long as it is used as directed, not
consumed. ``That appeals to people concerned about their exposure to
chemical residues,'' says Daeschel.
He plans to produce the wine-based disinfectant from waste wine.
Typically, wineries discard 1-3% of wine that they produce when it does
not meet quality or flavor specifications. The environmental
consequences of dumping waste wine are largely unknown, but probably tax
the biological oxidation demands of the local environment. Although some
waste wine is fermented to vinegar, the wine industry would welcome
additional outlets for discarded batches.
Carol Potera is a freelance writer in Great Falls, Mont.