Antimicrobial activities of red wine-based formulations containing plant extracts against Escherichia coli O157:H7 and Salmonella enterica serovar Hadar

Authors: Friedman, Mendel; Henika, Philip; Levin, Carol

Submitted to: Food Control
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/4/2014
Publication Date: 10/5/2014
Citation: Friedman, M., Henika, P.R., Levin, C.E. 2014. Antimicrobial activities of red wine-based formulations containing plant extracts against Escherichia coli O157:H7 and Salmonella enterica serovar Hadar. Food Control. 50:652-658.

Interpretive Summary: In an effort to improve microbial food safety, we initiated studies about 12 years ago designed to define the antimicrobial activities of different categories of food-compatible natural compounds and plant extracts against multiple foodborne pathogens. The first publication on relative activities of more than 100 plant essential oils and their bioactive components published in the Journal of Food Protection seems to have had a significant impact as evidenced by about 370 citations in the Scopus database. The most active compounds were then evaluated for efficacy in apple juice, meat and poultry products, on leafy greens, and as antimicrobial fruit and vegetable films. In the course of these studies, it became apparent that there is a need to determine antimicrobial potencies of combinations of natural antimicrobials, which might act additively or synergistically. This is a largely unexplored area. The objective of the present study was, therefore, to evaluate the antimicrobial activity of oregano oil and a phenolic-rich olive extract in red wine, each of which is known to exhibit antimicrobial properties, against the following four foodborne pathogens: E. coli O157:H7, Listeria monocytogenes, Salmonella enterica, and Staphylococcus aureus. The results suggest that some wine formulations can be used as broad-spectrum antibiotics to protect leafy greens and other food against contamination by pathogenic organisms.

Technical Abstract: We evaluated the bactericidal activities of red wine and red wine solutions containing a commercial olive extract called Hydrox-12, oregano oil, or a mixture of both in red wine against the following foodborne pathogens: Escherichia coli O157:H7, Salmonella enterica, Listeria monocytogenes, and Staphylococcus aureus. The following parameters that were expected to affect activity were evaluated: pH (3.6 and 7.0); temperature (4, 22, and 37°C), and incubation time (0, 5, 30, and 60 min). At pH 3.6, red wine alone was active only against Listeria, but Hydrox-12 protected Listeria against inhibition by red wine. The other formulations inhibited all four pathogens at pH 3.6. At pH 7.0, red wine and red wine plus Hydrox-12 were inactive against all four pathogens, whereas red wine plus oregano and red wine plus Hydrox-12 and oregano oil exhibited the highest inhibition of bacterial growth of all four pathogens. Activities generally increased with incubation temperatures and times. The three-component wine formulations that behave as broad-spectrum antibiotics are strong candidates for evaluation of antimicrobial effectiveness in animal and human food.