title: An alternative process for cleaning knives used on meat slaughter floors.
abstract: Traditionally on slaughter floors operator knives are cleaned by rinsing in hand wash water at 20-40 degrees C followed by brief immersion in baths termed "sterilisers" which contain water no cooler than 82 degrees C. Under Australian legislation, both domestic and export, it is possible for a meat processing establishment to apply to the Controlling Authority for permission to implement an alternative procedure providing that it is at least the equivalent of that legislated. No firm evidence appears to exist for the 82 degrees C requirement and the possibility of replacing this element of the knife cleaning procedure with an alternative procedure using 60 degrees C water and a longer immersion time was investigated at an abattoir slaughtering cattle and sheep. Knives were tested at a range of work stations located along beef and mutton slaughter floors for Aerobic Plate Counts (APCs) and E. coli. For knives used on the beef chain the mean log APC/cm(2) was 2.18 by the current knife cleaning process and 1.78 by the alternate procedure (P<0.001). Using the current system E. coli was isolated from cleaned knives on 20/230 (8.7%) occasions compared with 21/230 (9.1%) occasions using the alternative system. The mean log E. coli of positive knives was 0.43/cm(2) and 0.61/cm(2) from the current and alternative systems, respectively. On the mutton chain the mean log APC/cm(2) was 1.95 using the current knife cleaning process and 1.69 by the alternative procedure (P=0.014). Using the current system E. coli was isolated from cleaned knives on 24/130 (18.5%) occasions compared with 29/130 (22.3%) occasions using the alternative system. The mean log E. coli of positive knives was 0.90/cm(2) and 0.76/cm(2) from the current and alternative systems, respectively. It is concluded that using two knives alternatively, rinsing them in hand wash water, then immersing them between uses in 60 degrees C water provides a microbiological outcome equivalent to rinsing them and momentary dipping in 82 degrees C water.
authors.affiliation: Food Science Australia, PO Box 3312, Tingalpa DC, QLD 4170, Australia. Ian.Eustace@csiro.au
authors.forename: Ian
authors.initials: I
authors.lastname: Eustace
authors.forename: Jocelyn
authors.initials: J
authors.lastname: Midgley
authors.forename: Charles
authors.initials: C
authors.lastname: Giarrusso
authors.forename: Chris
authors.initials: C
authors.lastname: Laurent
authors.forename: Ian
authors.initials: I
authors.lastname: Jenson
authors.forename: John
authors.initials: J
authors.lastname: Sumner
mesh_terms: D000818:Animals; D001315:Australia; D002417:Cattle; D015169:Colony Count, Microbial; D004926:Escherichia coli / Q000254:growth & development / Q000302:isolation & purification; D005506:Food Contamination / Q000032:analysis / Q000517:prevention & control*; D005511:Food Handling / Q000295:instrumentation*; D005516:Food Microbiology; D005525:Food-Processing Industry / Q000295:instrumentation / Q000592:standards*; D006920:Hygiene; D008460:Meat / Q000382:microbiology*; D012499:Sanitation / Q000379:methods / Q000592:standards; D012756:Sheep