Influence of commercial deep chilling processes on early postmortem events in muscle that affect ultimate fresh pork tenderness and processing quality

Recent observations and evidence have supported the conclusion that rapid chilling (deep chilling) of pork carcasses in commercial processing plants has the potential to decrease pork tenderness. This is of concern because a loss in quality experienced by the consumer will have a detrimental impact on pork demand in global and domestic markets. The current experiment took an approach to carefully dissect the impact of deep chilling on pork carcasses by evaluating the effect of chilling protocol on pork quality within carcasses. This experiment was designed to investigate the direct effect of rapid on the quality of the center cut loin, and also on cuts from the ham, tenderloin, and shoulder. A second objective centered on determining the explanation for difference in tenderness. Finally, an experiment was conducted to determine the effect of the deep chilling process on quality characteristics of a cured and cooked ham.

The results of the study confirm observations that deep chilling of pork carcasses has the potential to decrease tenderness in fresh pork. The results do point out that this effect is not consistent with other muscles. In fact, no other cuts evaluated (from ham, tenderloin, and shoulder) were negatively affected by deep chilling. No consistent alterations in other quality features were observed with deep chilling. The effect of chilling on pork loin tenderness appears to be related to a tendency for the deep chilling method to slow down the normal “aging” process in the loin. Deep chilling of pork carcasses in this study had no consistent or significant effect on cured and cooked ham yields or ham color. In conclusion, deep chilling of pork carcasses does result in less tender center loin chops, but few consistent or meaningful differences in quality or processing parameters of other cuts in the pork carcass. The results suggest that processors should monitor the effects of chilling processes on center loin chop tenderness and consider methods to mitigate the observed consequence of decreased tenderness. Future investigations should address how features of pigs, carcasses and muscles (weight, fat content, metabolic profile) that make this outcome less likely to affect consumer perceived value and eating experience.