INITIAL POSTMORTEM PORCINE MUSCLE PH EFFECT ON HEAT-INDUCED GELATION PROPERTIES

Heat-induced gelation properties of the semimembranous muscle from induced DFD (dark, firm and dry) and normal pigs were characterized to evaluate the effect of muscle pH on strength and cooking loss of gels induced by a heating at 0.7C/min. The pH of muscle slurries (10% protein with 2% Nacl) were adjusted to 5.5, 6.0, 6.5, or 7.0 with 1 M 2-[N-Morpholino] ethanesulfonic acid buffer. Muscle with a high initial pH (DFD) had lower cooking losses at all adjusted pHs. Force required to penetrate the gel (Pf), force required to move plunger through the gel (Fp), and viscosity index of the gel were consistently higher for DFD muscle at each adjusted pH except pH 5.5. These results indicate that ultimate pH influences the thermal gelation properties of a meat product if the pH is ≥ 6.0. DFD muscle had desirable protein functionality and cooking yield.