Abstract: 【Objective】The Differential Scanning Calorimetry (DSC) was used in this test to scan the meat samples of pork, beef and mutton with different heat treatment temperatures. The purpose of this experiment is to study the relationship between the DSC thermogram and the heat treatment temperature of meat samples, to explore a sensitive and high-efficiency method to detect the EPT, in the hope of providing theoretical foundation for EPT detection during the actual production and circulation.【Method】Different heat treatments (for pork and mutton: 50℃, 60℃, 70℃, and 75℃; for beef: 50℃, 55℃, 65℃, 70℃, and 75℃）were carried out on a certain volume (2.0 cm×1.0 cm×1.0 cm) of meat cuboids. The meat cuboids were cooled to 4℃ after the center temperature reached to the aim temperature. The meat samples at 100.0 mg (the raw samples as control) taken from the center of meat cuboid were put into the thermoanalysis aluminium crucible. The crucible was sealed with lid and then balanced for a night at 4℃. A thermal scan was conducted from 40 to 80℃ at a constant heating rate of 1℃/min. The nitrogen flow was 20 mL·min^-1 and the shielding gas flow was 60 mL·min^-1. Finally, DSC thermograms of the meat samples with different center temperatures were obtained.【Result】The result showed that three peaks which had initial temperatures (pork: 50.83℃, 60.54℃, and 71.02℃; mutton: 50.76℃, 59.82℃, and 70.46℃; beef: 50.25℃, 56.29℃, and 71.92℃) and enthalpy of denaturation (pork: 0.4656 J·g^-1, 0.1394 J·g^-1, and 0.2053 J·g^-1; mutton: 0.0899 J·g^-1, 0.3116 J·g^-1, and 0.3842 J·g^-1; beef: 0.1078 J·g^-1, 0.4151 J·g^-1, and 0.3662 J·g^-1), respectively, were obtained from the raw pork, beef and mutton meat samples. The DSC thermograms of the three kinds of meat showed no significant changes when the heat treatment reached 50℃. The first peek vanished when the heat treatment reached 60℃ (for beef it reached 55℃), while, there were no obvious changes (P＞0.05) in the initial temperatures of the second and third peek but the enthalpy of that changed distinctly (P＜0.05). The second peek also disappeared when the heat treatment reached 70℃ (for beef it reached 65℃ and 70℃) and the initial temperatures of the last peeks changed slightly (P＞0.05), but the relevant enthalpy changed significantly (P＜0.05). All the three peaks of pork, beef and mutton meat samples vanished when the heat treatment temperature reached 75℃. It was concluded that the enthalpy of denaturation of the above meat samples gradually decreased and there were significant differences among the DSC thermograms of meat samples dealing with different temperatures. In this study, a success in EPT detection of the meat samples of different heat treatment temperatures was achieved.【Conclusion】Accordingly, the present study demonstrates that the denaturation of the above three kinds of meat has specificity to temperature and DSC can be used in the detection of EPT.

Key words: pork, beef, mutton, differential scanning calorimetry, endpoint temperature