29F-5 |
Antimicrobial activity of Origanox on the growth of Escherichia coli 0157:H7 |
S. R. K. DHARMAVARAM1, S. A. Ibrahim2, C. W. Seo2, and A. Shahbazi3. (1) Food Science and Nutrition, North Carolina A&T State University, 171-B Carver Hall, Greensboro, NC 27411-1064, (2) Dept. of Human Environment & Family Sciences, North Carolina A&T State Univ., Food Microbiology & Safety Lab., 171-B Carver Hall, Greensboro, NC 27411-1064, (3) Dept. of Agricultural & Biosystems Engineering, North Carolina A&T State Univ., Greensboro, NC 27411-1064 Origanox is used as a natural antioxidant in many food products. Origanox acts as a radical scavenger and prevents the development of lipid oxidation in foods. Research have shown that many spices have the ability to act as antimicrobial agents. The objective of this study was to evaluate the effect of origanox on the growth of Escherichia coli (E. coli) 0157:H7 in Brain Heart infusion (BHI) broth. E.coli 0157:H7 (380-94) and (7927) were inoculated (final inoculum level of 2.0 log CFU/ml) into BHI broth containing various concentrations of origanox (0.0, 0.1, 0.2, 0.3, 0.4, 0.5, 1.0, 1.5, 2.0 % W/V). Samples were allowed to grow at 37° C for 8 hrs. At seven one-hour intervals, One milliliter of treated sample was withdrawn, diluted with peptone water. 100ml of appropriate dilution was surface plated on BHI agar plates. Inverted plates were then incubated at 37° C for 24hr for bacterial enumeration. Results showed that addition of origanox caused a significant reduction in the growth rate of the pathogenic bacteria (P<0.05). Concentration as low as 0.5% was effective in inhibiting the growth of E.coli in BHI broth. During the 8 hr storage period, populations of bacteria increased by 6.0 log CFU/ml in control samples while populations increased by 2.0 log CFU/ml in treated samples (0.5%). The results indicate that origanox is an effective antimicrobial agent in controlling the growth of E.coli in food. This natural preservative could be used by the food industry to improve the food safety.
Session 29F, Food Microbiology: Control of foodborne microorganisms by antimicrobials
|