The effect of temperature on the drip,denaturation and extracellular space of pork longissimus dorsi muscle

Pork longissimus dorsi muscles were cut across the muscle into slices as soon as possible after slaughter. The slices were held at temperatures ranging from 10 to 37°C during the first 24 h post-mortem. 1–2% drip was obtained from slices held at 10°C and increased to 10–14% at 37°C. As the amount of drip increased, the protein concentration of the drip fell from about 150 mg/ml to 100 mg/ml. Some of this decrease could be attributed to the denaturation of sarcoplasmic protein, which amounted to a maximum of 19% in the samples with the highest drip. It is also suggested that diffusion of fluid from the myofilaments or sarcoplasmic reticulum could dilute the sarcoplasm. Denaturation of the myofibrillar proteins, as measured by their ATPase activity, was also observed but this was measurable only at holding temperatures above 30°C. The extracellular space which was 2–5% of the muscle section when the holding temperature was 10°C and drip was low, increased to a maximum of 16–25% at 37°C when drip was high. It is suggested that this is a contributory factor to the increase in drip with increasing temperatures.