The effect of ultrasound and photosonication treatment on polyphenoloxidase (PPO) activity, total phenolic component and colour of apple juice

摘要

In conclusion, ultrasound and photosonication processes are appropriate for the mass production of apple juice, either alone or with other processes. They could be applied either combined with other nonther-mal processes or with high temperature. Otherwise, browning could occur in apple juice, because PPO enzyme could not be completely inactivated.