Measurement of freezing point of tilapia fish burger using differential scanning calorimetry (DSC) and cooling curve method

The aim of this work was to determine the freezing point (Tf) of tilapia (Oreochromis niloticus) fish burger using the cooling curve and differential scanning calorimetry (DSC) method. Cooling curves were obtained for two household refrigerators, a freezer with no quick freeze function and another one equipped with a quick freeze compartment. Freezing point, freezing time and freezing rates were determined from the cooling curves. The freezers showed slow freezing rates ranging from 0.10 to 0.40 cm/h. The quick freeze function improved the freezing process, as it significantly reduced the freezing times by significantly increasing freezing rates. Tf of the tilapia fish burger was (−2.7 ± 0.1) °C and no significant difference between freezing rates and the DSC method was observed. This investigation demonstrated that the cooling curve method using a simple experimental apparatus and domestic refrigerators can be used to measure freezing point of high moisture foods.