Evolution of hydrophobic polypeptides during the ageing of exudative and non-exudative pork meat

Thirty-six carcasses from 6-month-old pigs were classified in different exu dative groups based on measurements of pH(2h), PH24h, the colour parameter L* and drip loss. A fraction containing polypeptides between 66 and 21 kDa was analysed by reverse phase chromatography at 2-h post-mortem and the evo lution of 8 polypeptide fractions followed during ageing and related to mea t quality. Three polypeptide (fractions P2, P3 and P4) at 2-h post-mortem s howed significant lowest area values in the dark firm and dry class. During ageing, the higher content of P4 in exudative meats at 8-h post-mortem cou ld be due to activation of the cathepsin system. On the other hand, P3 and P4 increased in DFD meats during the first 96-h post-mortem probably due to higher calpain activity. Few differences in polypeptides were related to m eat qualities although they are important as precursors of small peptides a nd free amino acids. (C) 2001 Elsevier Science Ltd. All rights reserved.