Impact of Carcass Chilling System on Carcass Characteristics and Biochemical Changes in Beef Carcasses

Effective and efficient chilling of beef carcasses will directly influence meat quality and consumer acceptance. Over the past century the United States’ meat industry has evolved, and spray chilling system have become common practice utilized by the beef industry. However, many of the chilling systems presently in use were designed to chill carcasses averaging lighter than the average beef hot carcass weight of today. Beef hot carcass weight has increased 68 kilograms from 1991 to 2019. The increase in beef hot carcass weight could result in longer chilling periods and present possible challenges for chilling systems used by the beef industry and impact meat quality. The impact of carcass chilling system on protein degradation postmortem has not been heavily investigated, however; the degradation of desmin early postmortem has been found to play a vital role in tenderness development. The objective of this thesis was to determine the impact of air and spray chilling systems on carcass characteristics, instrumental color, and biochemical changes (temperature and pH decline of round, loin, and chuck primal, and protein degradation) in beef carcasses. Temperature decline was recorded by data loggers that were inserted into the round, loin, and chuck at varying positions and remained during the 24-hour chilling period. At 24 hours postmortem, a single 2.54 cm steak was removed from the longissimus lumborum to be utilized for protein degradation analysis. There was no impact of chilling treatment on carcass characteristics, instrumental color, pH decline, or protein degradation. Spray chilling beef sides enhanced temperature decline in the round, loin, and chuck. Internal temperature decline differed at data logger position in the round and chuck. Tissues closer to the surface reached lower temperatures and chilled faster in both treatments. Additional research is needed to fully understand the impact of spray chilling systems on protein degradation postmortem in beef carcasses