3.4. Evaluation of optimal drying conditions
Synthetic evaluation index (S, Eq. (4)), considering the relative product colour, rehydration rate, rehydration ratio and dehydration rate, was calculated for each of the drying methods examined (Table 3). The dehydration rate constant (kd) was calculated by the product of Page constants kpand n. In terms of drying time, rehydration time and colour, the drying method that gave the highest S value was the combination drying, i.e.MW = 300 W, T = 80◦C. The optimal drying method at this level produced an acceptable final product in terms of colour and moisture content, with relatively fast rehydration properties and within a relatively short processing time.