18 – Carcass chilling

Publisher Summary This chapter presents that to effectively reduce microbial contamination on carcasses, it is essential to control their proliferation on the carcass surface and as such it is imperative to maintain an adequate chilling process. Due to metabolic activity in pre-rigor muscle of carcasses, the average carcass temperature may increase to about 40 °C immediately following slaughter. Carcasses are typically cooled before being further processed; however, the period of time it takes carcasses to cool from temperatures as high as 40 °C to chiller temperatures provides an opportunity for proliferation of spoilage and pathogenic bacteria, especially psychrotrophic organisms. Ideally for the safety of the product the carcass should be chilled as rapidly as possible and, as such, minimize the growth of the microflora on the carcass surface and, although psychrotrophic growth is a certainty on chilled carcasses, the extent to which it occurs must be controlled by ensuring that the chilling process is under control. Alternatively, carcasses may be hot boned; that is, the carcass is boned while hot and the resulting primals are chilled. The advantage of hot boning is more rapid chilling of the meat due to better heat dissipation with the relative increase in surface area of smaller portions; however, the problem with wet cut surfaces is that they are easily contaminated and prone to high rates of evaporative weight loss. Most hot boned carcasses are chilled using batch systems.