title: Antibacterial effect of monocaprylin on Escherichia coli O157:H7 in apple juice.
abstract: The antibacterial effect of low concentrations of monocaprylin on Escherichia coli O157:H7 in apple juice was investigated. Apple juice alone (control) or containing 2.5 mM (0.055%) or 5 mM monocaprylin was inoculated with a five-strain mixture of E. coli O157:H7 at approximately 6.0 log CFU/ml. The juice samples were stored at 23 or 4 degrees C for 14 or 21 days, respectively, and the population of E. coli O157:H7 was determined on tryptic soy agar plates supplemented with 0.6% yeast extract. At both storage temperatures, the population of E. coli O157:H7 in monocaprylin-supplemented juice samples was significantly lower (P < 0.05) than that in the control samples. The concentration of monocaprylin and the storage temperature had a significant effect on the inactivation of E. coli O157:H7 in apple juice. Monocaprylin at 5 mM was significantly more effective than 2.5 mM monocaprylin for killing E. coli O157:H7 in apple juice. Inactivation of E. coli O157:H7 by monocaprylin was more pronounced in juice stored at 23 degrees C than in the refrigerated samples. Results of this study indicated that monocaprylin is effective for killing E. coli O157:H7 in apple juice, but detailed sensory studies are needed to determine the organoleptic properties of apple juice containing monocaprylin.
authors.affiliation: Department of Animal Science, Unit 40, University of Connecticut, 3636 Horsebarn Hill Road Extension, Storrs, Connecticut 06269, USA.
authors.forename: Manoj Kumar Mohan
authors.initials: MK
authors.lastname: Nair
authors.forename: Hanem
authors.initials: H
authors.lastname: Abouelezz
authors.forename: Thomas
authors.initials: T
authors.lastname: Hoagland
authors.forename: Kumar
authors.initials: K
authors.lastname: Venkitanarayanan
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001628:Beverages / Q000382:microbiology* / Q000592:standards; D002210:Caprylates / Q000494:pharmacology*; D015169:Colony Count, Microbial; D004305:Dose-Response Relationship, Drug; D019453:Escherichia coli O157 / Q000187:drug effects* / Q000254:growth & development; D005516:Food Microbiology; D005519:Food Preservation / Q000379:methods*; D027845:Malus; D013649:Taste; D013696:Temperature; D013997:Time Factors
chemical_list: D000900:Anti-Bacterial Agents; D002210:Caprylates; C031492:octanoic acid