Effects of Early Post-Mortem Rate of pH fall and aging on Tenderness and Water Holding Capacity of Meat from Cull Dairy Holstein-Friesian Cows

Abstract

Fast or slow muscle pH fall may give unacceptable purge losses or tough meat, depending much on concomitant evolution of muscle temperature early post-mortem, costing millions of euros to the meat industry. Tenderness and purge losses of Longissimus thoracis/lumborum ( LTL) and Gluteus medius ( Gm) sampled from cull dairy cows differing in production status (10 lactating vs. 22 dried off) and aging time, were evaluated regarding different rates of pH 2 fall. Shear force related to pH 2 was dependent on muscle and aging time. The intermediate glycolysis led to lower shear force in LTL, while the faster produced best quality in Gm. Purge was influenced by pH 2 (P=0.0077), aging (P<0.0001) and muscle*pH 2 interaction (P<0.0001). Aging affected thawing (P<0.0001), grilling (P=0.0004) and overall losses (P<0.0001). Under the ruled chilling regime, the fast pH fall in Gm and the slow pH fall in LTL approached out of the ideal pH6/temperature limits, being compatible with heat and cold shortening, respectively.