Alternative procedures are permitted if the efficacy is proved to be equivalent.
In the present study,
various time–temperature combinations together with pure water,
water with lactic acid (2 %),
and the use of ultrasound with and without lactic acid (2%) were investigated.
Steel plates were covered with fat and protein and then inoculated with a standardized bacterial contamination assembled according to the composition of bacterial contamination found in a previous field trial conducted with regard to the slaughter
of pigs.
Several combinations with diverse temperatures and time intervals were tested until no microbial load was detectable by using a wet–dry-swab technique that had previously been tested to ensure maximum bacterial recovery.
The following were effective in bringing the tested bacterial flora below the detection limit: