3.2. DSC method
The DSC method can be used to obtain the freezing point, heat of fusion (DH) and apparent specific heat. Fig. 3 shows a typical endothermic curve of the tilapia fish burger illustrating the peak and onset points. The onset of melting was considered as the freezing point (Bai et al., 2001). Tf and DH of tilapia fish burger was (_2.8 ฑ 0.4) _C and (136.4 ฑ 16.6) J/g, respectively. Tf was not significantly different from the Tf (_2.7 ฑ 0.1 _C) obtained by the cooling curve method using household freezer. This result validated that both methods can be used to determine freezing points of high moisture foods, such as fish burger. Apparent specific heat (Cpapp) between temperature range _20 to 0 _C, where phase change happened, increased rapidly from 0 to 30 J/g _C. Matuda et al. (2011) found that Cpapp of bread dough increased sharply from 2 to 15 J/g _C between the temperature range from _20 to 0 _C. Chen and Pan (1995) found