Translocation of surface-inoculated Escherichia coli into whole muscle nonintact beef striploins following blade tenderization.
Academic Article
Overview
Research
Identity
Additional Document Info
Other
View All
Overview
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.
