Mathematical modeling of apparent specific heat capacity of channel catfish with different microwave heating time

Channel catfish fillets with different microwave heating times were evaluated by differential scanning calorimetry and low-field nuclear magnetic resonance to build suitable modeling of apparent specific heat capacity (C-p) ranging from -60 to 90 degrees C (except the obvious phase change region from -20 to 20 degrees C). The content of bound water (W-b), immobilized water (W-i), and free water (W-f) were weighted and calculated. According to non-linear fitting of experimental data, the obtained empirical equation of C-p, temperature (T), W-b, W-i, and W-f of samples was:C-p = (a + bw(b) + cw(i)+ dw(f) + eT)/(1 + fw(b) + gw(i) + w(f)). The equation was in good correlation (R-2 > 0.95) with the experiment data and could provide a basis for improvement of processing parameters.