Drying characteristics and mathematical modeling of controlled freezing point drying of grass carp fillets

The ice temperature vacuum drying characteristics of grass carp were examined at different levels of vacuum pressures(600~700,1100~1200 and 1600~1700 Pa)and material thickness(3,5 and 7 mm)respectively. The mathematical modeling of ice temperature vacuum drying of grass carp was established by the changing of moisture ratio. The results showed that vacuum pressure and material thickness all affected the drying rate remarkable. The lower the vacuum pressure and the material thickness were,the shorter the drying time was. The midilli model could better simulate the ice temperature vacuum drying process of grass carp with the correlation coefficient(R²)>0.997,reduced chi-square(χ²)<0.08‰ and root mean square error(RMSE)<0.85%. The predicted values of the model were in good agreement with the experimental values. Therefore,the midilli model could be used to describe the ice temperature vacuum drying of grass carp.