Location: Warmwater Aquaculture Research UnitTitle: Inactivation of Enterobacter sakazakii by Water-soluble Muscadine Seed Extracts Author
Submitted to: International Journal of Food Microbiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/10/2008
Publication Date: 2/28/2009
Citation: Kim, T.J., Silva, J.L., Weng, W.L., Chen, W.W., Corbitt, M., Jung, Y.S. 2009. Inactivation of Enterobacter sakazakii by Water-soluble Muscadine Seed Extracts. International Journal of Food Microbiology. 129:3295-3299. Interpretive Summary: Muscadines are native to the SE US. They contain high amounts of polyphenols that could be used as natural antimicrobials and antioxidants in foods. Water extracts of muscadine byproducts were found to strongly inhibit Chronobacter sakazaki (formerly known as E. sakazakii)i, a foodborne pathogen affecting babies. This product could be integrated in baby foods to enhance their safety.
Technical Abstract: Hot and cold water-soluble muscadine (Vitis rotundifolia) seed extracts and their polar and polyphenol fractions from two Muscadine cultivars (‘Ison’, purple and ‘Carlos’, bronze) were investigated for their inhibition of Enterobacter sakazakii. The heat treatment on each seed extract not only increased total phenolics and tannic acid but also enhanced antimicrobial activity against two strains of E. sakazakii. Within 1 h, all seed extracts reduced an initial population ( 6 log CFU/mL) of E. sakazakii to a non-detectable level (minimum detection limit, 10 CFU/mL). Regardless of extraction method and cultivar, only the polar fractions which contained malic, tartaric and tannic acids showed antimicrobial activity against two strains of E. sakazakii. The polyphenol fractions which contained gallic acid, catechin, epicatechin, ellagic acid and pigments showed slight inhibition against E. sakazakii. Results showed that water-soluble muscadine seed extracts (pH 3.3–3.78) contained strong antimicrobial inhibitors against E. sakazakii while acidified peptone water (pH 3.3) did not show any antimicrobial activity.