Effects of electrical stimulation on early postmortem muscle pH and temperature declines in pigs from different genetic lines and halothane genotypes

Abstract

The objective of this study was to determine if electrical stimulation (ES) early postmortem is an effective method to generate PSE-like meat. One hundred and thirty-eight gilts (85–125 kg) from heavy muscled (HM), normal muscled (NM), and light muscled (LM) porcine genetic lines were subjected to one of two treatments: ES (26 pulses of 500 V, 60 Hz) at 3 min postmortem or non-stimulated (NS). Pigs from HM line were further characterized as halothane (HAL) carriers (Nn) or non-carriers (NN). ES carcasses had lower ( P<0.0001) pH values and higher ( P<0.0001) temperature than NS carcasses during the first 56 min postmortem. ES carcasses had lower ( P<0.0001) a*-values, and color and firmness scores, as well as higher ( P<0.0001) drip loss and L*-values. No significant interactions were found between treatment and genetic line or HAL gene status with regard to pH, temperature, or quality characteristics. Temperature and pH declines within the first hour postmortem were not affected by genetic line, but slight ( P<0.01) quality differences were observed. Nn and NN did not differ in pH or temperature within the first hour postmortem, but Nn carcasses had lower ( P<0.01) color and firmness scores, and higher ( P<0.05) drip loss. These results show that ES early postmortem is an effective method for simulating PSE development in pigs of different muscling and HAL gene status, and suggest that pH and temperature decline alone cannot explain all aspects of pork quality.