Cold induced toughening in excised pork as affected by pH, R value and time at boning

Porcine M. longissimus dorsi from paired sides of 87 carcasses representing a wide range of post-mortem glycolic rates were obtained to study the cold toughening potential in early excised cuts (right sides) as compared to a conventional, cold boning procedure (left sides). The pH, R value and time at boning were measured and evaluated for their effect on tenderness. The early excised cuts were chilled by two different chilling rates: fast chilling in ice water or chilling by air at 2-4°C in a conventional chilling room. The cold toughening potential for excised fast chilled cuts was significantly (P < 0.001) affected by pH, R value and time at boning, the latter parameters however being significantly correlated (P < 0.001). From partial regression analysis, the R value appeared to be the main factor involved in tenderness variations. Thus the R value as measured at time of boning was found to be the parameter showing the highest predictive value for estimating the risk of cold toughening in early excised cuts. When early excised cuts were chilled in air at 2-4°C, the results from the present study showed tenderness levels comparable to the conventional cold boning procedure, irrespective of pH, R value and time at boning.