WHITE PAPER These events can lead to subsequent cross- contamination of neighbouring carcasses and equipment by splash and handling, and cross- contamination via contact with infected surface after scalding and singeing. • At the cutting stage through to retail – To the pork via cross-contamination from hands, equipment and surfaces, and as a result of slow or inadequate chilling that allows bacterial proliferation. A study in a small slaughterhouse in Ireland measured the number of Salmonella on pig carcasses (Bolton et al., 2002). The sampling was performed at different stages of pig processing. Salmonella spp. on pigs at the farm was 27%, decreasing to 10% after pre-slaughter washing, but increasing again to 50% following stunning and bleeding. Hair removal (i.e. scalding, de-hairing and singeing) resulted in a significant decrease in viable bacterial counts but significant increases were observed after pre- evisceration washing and final chilling. CONTROL OF SALMONELLA WITHIN PIG PROCESSING Following the introduction of a Salmonella control program in Denmark in 1995, extensive research into the risk factors associated with Salmonella in pig processing has been conducted, and a series of intervention factors have been developed. In particular: • The separation of Salmonella-free and infected animals, and the thorough cleaning and disinfection of the environment and equipment used between rearing, transport, lairage, slaughter and butchering of these two groups, at all stages is recommended. • The adoption of Hazard Assessment of Critical Control Points (HACCP) procedures. • The hygienic design (clean ability) of transport vehicles, buildings and equipment used for pig processing – these should allow easy and practical access to all contaminated areas and be made of smooth, washable, impermeable, chemical resistant, non-toxic durable materials. • Staff hygiene training - the skills and attitude of the butchers, slaughter men and meat handlers can impact considerably on the overall quality of the product and they should be provided with the facilities and training to ensure adherence to personal hygiene and proper slaughtering and meat transport. Figure 2: Enterobacteriaceae isolated from pig carcasses by swabbing at each stage of processing (Berends et al., 1997; Bolton et al., 2002; Pearce et al., 2004). Enterobacteriaceae CFU/cm2 Enterobacteriaceae numbers on pig carcasses at different stages of processing 4.5 4 3.5 3 2.5 2 1.5 1 0.5 0 Sticking Scalding Dehairing Singeing Polishing Evisceration Vikan A/S - Department of Research & Development 03 Copyright © 2013 Vikan A/S · All Rights Reserved
Download PDF file