Cold water, ultra-high pressure cleaning of abattoirs

Abstract

SUMMARYCold water (10° C) at ultra-high pressure (38·5–49 kg/cm2) was compared with (a) hot water (65·6–82·2° C) at low pressure (4·2–5·6 kg/cm2) and (b) hot water containing a detergent (2% (w/v) sodium silicate). Seven sites were examined in a beef abattoir and six in a bacon factory.Three surfaces in the beef abattoir had lower residual colony counts (higher reductions) after hot water/low pressure than after cold water/high pressure. However, the differences were not significant (P> 0·05). The range of the mean log10count/cm2before cleaning was 4·02–5·15, and after cleaning 1·73–2·32 (hot water) and 1·9–2·85 (cold water).On three of the remaining sites, the three methods were compared. The total differences between treatments were not significant (P> 0.05), although there was an effect of surface and an interaction between surface and treatment. The cold water produced lower residual counts on three sites in the bacon factory than the hot water (45–54°C). However, the differences were not significant on the remaining surfaces.