SURVIVAL OF CAMPYLOBACTER, SALMONELLA AND YERSINIA SPP. IN SCALDING WATER USED AT PIG SLAUGHTER

Strains of Campylobacter, Salmonella and Yersinia spp., three strains of each, were tested for resistance to heat in pig scalding vat water pH 8. The campylobacter were tested at 53, 54 and 56-degrees-C, the salmonellae and yersiniae at three temperatures varying from 58 to 62-degrees-C. D values obtained were compared with corresponding D values determined in physiological saline pH 7. The D values for the campylobacter and salmonellae were statistically significantly lower in the scalding water. The difference in pH between the two heating media was considered to be the cause of these differences. For the Yersinia strains, on the other hand, corresponding Dvalues were practically equal. The tolerance of yersiniae to dilute alkali might explain these observations. The results of the work indicate that only small numbers of campylobacter, salmonellae and yersiniae can be expected to survive in scalding water at commonly used temperatures (58-62-degrees-C). To minimize the risk of contamination via the scalding water, however, scalding water temperatures not less than 62-degrees-C are recommended.