According to Lewicki, the growth of most fungi, molds and bacteria is inhibited when
water activity value is less than 0.7 (Lewicki, 1999).
Results from water activity examination are shown in Fig. 8. Water activity valuesare similar for both the convection process sample and the ultrasound assisted process
sample. The aw value is high compared to e.g. Nowacka, but it is within the safe
limit (Nowacka et al., 2010).