Effects of breed and marination on the sensory attributes of pork from Large White and Hampshire-sired pigs.

The effects of breed and marination were tested for their effects on meat pH, water holding (marinade uptake and losses) and eating quality (tenderness, juiciness and flavour). Loins were removed from one side of 20 Large White-sired and 20 Hampshire-sired pigs after slaughter, cut into four pieces and injected to 112% of their initial weight with water, a polyphosphate-containing marinade (pH 7.7) or a high pH marinade (pH 10.3). An uninjected piece of loin served as control. Samples were left overnight and then frozen before being thawed, cooked and assessed by a trained ten member sensory panel using 1-8 category scales. Hampshires had higher intramuscular fat (0.95%) than Large Whites (0.62%) but otherwise the effects of breed were small compared with marination. Both marinades significantly increased meat pH from 5.5 (control) by 0.2U, significantly reduced the cooking loss and increased the meat yield from about 80% to 90%. Water-injected samples lost large amounts of added water as drip after thawing and had a yield (76%) similar to the control. Marinaded samples retained more water post-cooking. Both marinades significantly increased tenderness (p<0.001) and juiciness (p<0.001) by about 1.0U compared with the control (4.4 for tenderness and 4.2 for juiciness). Pork flavour, however, was significantly reduced (p<0.001) and abnormal flavour was significantly increased (p<0.001) by marination. Tenderness was positively correlated with pH after injection (0.83) and yield (0.75); juiciness was also positively correlated with pH after injection (0.78) and yield (0.87). The absence of any significant difference in eating quality between control and water-injected samples, and the relatively large effects of marination, suggest that retained water (after cooking) is crucial in determining perceived tenderness and juiciness in pork.