Experimental and mathematical modeling analysis of freeze-drying kinetics for ginger slices with different thickness

In this study, the freeze-drying (FD) behavior of ginger (Zingiber officinale) at thicknesses of 5 and 7 mm was analyzed experimentally and statistically. The drying process was evaluated using ten empirical models to decide which was most proper for predicting weight reduction. Among the evaluated models, the Logarithmic Model was the most correct in describing the drying kinetics for both sample thicknesses, showing the lowest error rates of 8.39% for 5 mm samples and 8.42% for 7 mm samples. The 5 mm samples had statistical parameters of correlation coefficient (R2) = 0.9902, chi-square (X2) = 1.402×10-3 and root mean square error (RMSE) = 0.03211. The 7 mm samples had R2 = 0.9986, X2= 1.153×10-3, and RMSE = 0.03411. Additionally, the calculated effective moisture diffusion coefficient (Deff) values for 5 mm and 7 mm were 2.075×10-7 m2/s and 4.079×10-10 m2/s, respectively, which are in line with the values reported for different food items.