Effect of different post mortem temperatures on carcass quality of suckling lamb

Abstract

The effect of post mortem treatment on microbiological lamb carcass quality was studied. Suckling lambs carcasses were assigned to three different post mortem treatments: conventional (2 ℃ for 24 h), ultra-rapid (−20 ℃ for 3.5 h then 2 ℃ until 24 h post mortem) and slow (12  ℃ for 7 h then 2 ℃ until 24 h post mortem). Carcass pH and temperature were measured at 0, 3.5, 7 and 24 h post slaughter. Lamb carcasses were sampled for total aerobic viable and Enterobacteriaceae counts just after dressing and 24 h post mortem. A significant effect (p < 0.05) of post mortem treatment on carcasses temperature and pH was found corresponding the faster pH fall to slowly chilled muscles. However, no differences were found at 24 h post mortem among treatments in both parameters. Regarding microbiological results, carcasses of ultra-rapid treatment had the lowest total aerobic viable and Enterobacteriaceae counts and those belonging to conventional treatment had the highest total aerobic viable counts. From 0 to 24 h post mortem, an increase of total aerobic viable was observed in conventional and slow treatments whilst Enterobacteriaceae counts remained constant in all cases. From a microbiological point of view, the ultra-rapid treatment was the only one allowed to maintain the hygienic carcasses quality. However, according to pH and temperature results the carcasses subjected to this treatment may be susceptible to cold shortening.