89D-21 |
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V. EDWARDS1, I. Goktepe2, B. Milford3, and M. Ahmedna2. (1) Dept. of Human Environment &Family Sciences, North Carolina A&T State Univ., 161 Carver Hall, Greensboro, NC 27411, (2) Dept. of Human Environment & Family Sciences, North Carolina A&T State Univ., 161 Carver Hall, Greensboro, NC 27411, (3) Food Science & Nutrition Program, North Carolina A&T State Univ., Dept. of Human Environment & Family Sciences, 161 Carver Hall, Greensboro, NC 27411 There has been a growing interest in new antimicrobials that are natural and safe. Plant extracts have been investigated for a variety of purposes, including the existence of antibacterial and medicinal properties. Poke weed (Phytolacca americana) is an American perennial shrub which has been used as folk medicine to treat viral and fungal infections for centuries. It contains triterpenoid saponins, alkaloids, phytolaccic acid, formic acid, lectins, tannin, antiviral protein (PAP), fatty oil, resin, and sugars. Although poke weed has been broadly used as a medicine by American Indians, there is very limited information on its properties against foodborne pathogens. Therefore, this study was carried out to evaluate the antibacterial properties of poke weed's root and berries against common foodborne pathogens. Poke roots and berries were freeze-dried and powdered. The powdered materials were extracted with ethanol/water mixture and/or water. Antimicrobial activity of poke root and berry extracts were tested against 6 species of gram positive and negative bacteria. Screening poke root and berry extracts for their antimicrobial activity was conducted using the Minimum Inhibitory Concentration (MIC) assay. The water extracts of poke root did not show significant antimicrobial activity against bacterial species at the concentrations tested, while alcohol extract was effective on all bacteria tested, except Bacillus cereus. Streptococcus sp. was the most sensitive microorganism to alcohol extract of poke berries with MIC value of 20 mg/mL, followed by S. aureus and E. coli. The MIC values for water extract of poke berries ranged from 40 to 60 mg/mL. Overall alcohol extracts of poke root and berries exhibited more inhibitory effect on the bacteria tested. Although extracts of poke root and berries were effective against pathogenic bacteria, their inhibitory ability in food matrices and the impact on sensory quality of food require more research to ensure safe use in food products.
Session 89D, Food Microbiology: Antimicrobial effects on foodborne microorganisms
2005 IFT Annual Meeting, July 15-20 - New Orleans, Louisiana |