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 (T-f) 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. T-f of the tilapia fish burger was (-2.7 +/- 0.1) degrees 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. (C) 2015 Elsevier Ltd. All rights reserved.