title: Translocation of surface-inoculated Escherichia coli into whole muscle nonintact beef striploins following blade tenderization.
abstract: Translocation of Escherichia coli among beef loins processed with a mechanical tenderizer was evaluated. Two beef striploins were inoculated on the lean side with 6.4 to 7.2 ml of a nalidixic acid-resistant E. coli at 8.2 to 10.1 log CFU/ml. Total E. coli inoculated onto striploins ranged from 1.12 × 10(9) to 9.10 × 10(10) CFU. Striploins were passed once (lean side up, anterior end first) through a mechanical blade tenderizer. After the inoculated striploins had been tenderized, uninoculated beef striploins (n = 5) were passed once (lean side up, anterior end first) through the same mechanical tenderizer. This procedure was repeated twice for a total of 12 striploins. Six core samples were taken from each striploin starting with the anterior end. Each core was cut into six sections; sections 1 through 4 represented the top 4 cm of the core sample, and sections 5 and 6 represented the remaining part of the core split in half. After tenderization, E. coli levels were highest (P < 0.05) in loin 1. Loin 2 had higher levels (P < 0.05) than did loins 4, 5, and 6. No differences in E. coli levels (P > 0.05) were found among loins 3, 4, 5, and 6, for which levels were below the limit of detection. Levels of E. coli from section 1 were higher than those for all other sections. Section 2 had higher levels (P < 0.05) than did sections 3, 4, 5, and 6. E. coli recovery from section 6 was higher (P < 0.05) than that from sections 3, 4, and 5. No differences in E. coli recovery (P > 0.05) were found among sections 3, 4, and 5. Data indicate that even after inoculation of E. coli a high initial levels, contamination from one loin to another is quickly reduced to < 10 CFU/g.
authors.affiliation: Freedman Meats, Dallas, Texas 75237, USA.
authors.forename: Daniel F
authors.initials: DF
authors.lastname: Johns
authors.forename: Christy L
authors.initials: CL
authors.lastname: Bratcher
authors.forename: Chris R
authors.initials: CR
authors.lastname: Kerth
authors.forename: Thomas
authors.initials: T
authors.lastname: McCaskey
mesh_terms: D000818:Animals; D018988:Bacterial Translocation; D002417:Cattle; D015169:Colony Count, Microbial; D003257:Consumer Product Safety; D004866:Equipment Contamination; D004926:Escherichia coli / Q000502:physiology*; D005506:Food Contamination / Q000032:analysis / Q000517:prevention & control; D005511:Food Handling / Q000295:instrumentation* / Q000379:methods*; D005516:Food Microbiology; D006801:Humans; D008460:Meat / Q000382:microbiology*