The magnitude of the effects of ultrasound on the drying rate
also depends on the ultrasonic power level applied. As can be seen
in Fig. 4, an ultrasonic intensity threshold can be achieved to find
some evidence of the effect of ultrasound on the kinetic parameters
of the process. Above this threshold, the more power is applied, the
higher the values of diffusivity and mass transfer coefficient that
can be obtained and, therefore, the faster the drying process
(García-Pérez et al., 2009). Above the threshold, the relationship
between the kinetic parameters and the applied ultrasonic power
was linear for the whole range tested.