LACTIC-ACID DECONTAMINATION OF FRESH PORK CARCASSES - A PILOT-PLANT STUDY

Lactic acid decontamination (LAD) was carried out in an abattoir on po rk carcasses, artificially contaminated with Salmonella typhimurium in faeces suspensions. The surface contamination with S. typhimurium ran ged from 1-2 log(10) cfu/cm(2). Before cold and hot LAD was undertaken , the inoculum was allowed to adhere to the meat surface for 20 min. C old LAD consisted of treatment for 60 s with 2% (pH 2.3) or 5% (pH 1.9 ) lactic acid (LA); for hot LAD the exposure times were 30, 60, 90 and 120 s. The spray nozzle temperatures were 11 degrees C and 55 degrees C, and that of the treated meat surface 16-18 degrees C and 36-38 deg rees C, respectively. Treatment with cold 2% and 5% LA for 60 s elimin ated S. typhimurium from pork carcasses inoculated with ca. 1 log(10) cfu/cm(2), but not from those inoculated at ca. 2 log(10) cfu/cm(2). H owever, this could be achieved by hot 2% and 5% LA sprayed for 60-120 s. Also exposures of at least 30 s using these hot LA solutions elimin ated S. typhimurium consistently from carcasses inoculated with ca. 1 log(10) cfu/cm(2). Rinsing-off contributed only marginally to contamin ation reduction. Application of 2% or 5% LA for 120 s led to an unacce ptable deterioration of the organoleptic qualities of the meat. Additi on of nicotinic and ascorbic acid as colour stabilisers to the sprayin g solutions reduced these changes to just acceptable levels when 2% LA was used.