Postmortem changes in adductor muscles from Aulacomya ater ater (Molina) stored at 2-4 degrees C. A differential scanning calorimetric study

Postmortem thermal behavior of Aulacomya striated adductor muscles stored at 2-4 degrees C was investigated by differential scanning calorimetry (DSC). The exothermal peak present in prerigor muscles from different species was not evident in DSC thermograms of either fresh or cold-stored adductor muscles. ATP content and pH of the muscles fell sharply in the first 8 h of storage. At this time the greatest increases in both total denaturation enthalpy and denaturation enthalpy related with the first transition were observed. The addition of exogenous ATP to whole muscle after 18 h of storage (low endogenous ATP level) produced a decrease in total enthalpy as a result of a decrease in the peak I enthalpy. These results support the idea that the exothermal peak is not evident in DSC thermograms because it coincides with the first endothermal transition