10 May 2002

Stress detector for higher meat quality

PIGMEAT quality could be improved by using a technique which measures the acidity of the muscle to identify pigs which have suffered stress, says Jeff Wood of Bristol Vet School.

The continuing integration and co-operation between all partners in the chain of supply from farmers to retailers has lead producers and processors to seek ways of guaranteeing a more uniform product for the consumer.

"Variation in meat quality has been linked to colour and water retention in muscle. Both of these factors have been tied to muscle acidity, pre and post slaughter," says Prof Wood.

"Significant falls in acidity (pH) after slaughter, due to either poor handling or because pigs are carrying the stress gene, will lead to muscle becoming pale and wet. This will lower meat yield and meat will be tough when eaten."

Stress over a longer period prior to slaughter causes pH to remain high with muscle being unattractively dark, he adds.

Measuring pH should aid the identification of meat quality problems and will lead to improvements in both the eating quality of pig meat and the yield of cuts from carcasses, according to Prof Wood.

Simon Jennings, technical manager at processor Bowes of Norfolk, believes regular monitoring of pH is a key quality indicator in pig meat. "While not used as a routine production tool in the UK, it is common overseas in areas such as Europe and Japan," adds Mr Jennings, who suggests that perhaps higher welfare conditions in the UK make it less of a problem here.

"It should be possible, with regular pH testing, to trace problem batches of meat back to farm of origin and identify and eliminate problems causing either high or low pH."

One way to reduce pig stress at slaughter is to handle them regularly on farm says Mr Jennings. "Pigs which are handled routinely load easily and are less stressed on arrival at the abattoir."

A factsheet on pig meat quality will be available from the KT stand, 151, at the Pig & Poultry Fair or by phone (01970-823028, fax 01970-828357). &#42