2.3.4. Ultrasonic pretreatment (Variant IV)
Ground waste bread samples (30 g dry matter basis) were
slurred in ca. 150 mL of distilled water preheated to 35 ?C in a
300 mL conical flasks. The flasks were placed in an ultrasonic bath
SONIC-0.5 (Pulsonic, Poland) for 5 min, as described by the
manufacturer the power of the bath was 250W and ultrasonic frequency
was 40 kHz. After this time the experimental procedure
was the same as in Section 2.3.1.