The inactivation kinetics of polyphenol oxidase in mushroom (Agaricus bisporus) during thermal and thermosonic treatments

• Published in: Ultrasonics sonochemistry 2013-03, Vol.20 (2), p.674-679
• Main Authors: Cheng, X.-f., Zhang, M., Adhikari, B.
• Format: Article
• Language: English
• Subjects: Agaricales - enzymology; Catechol Oxidase - antagonists & inhibitors; Catechol Oxidase - metabolism; Chemistry; Enzyme Stability; Exact sciences and technology; General and physical chemistry; Hot Temperature; Inactivation; Kinetics; Mushroom; Physical chemistry of induced reactions (with radiations, particles and ultrasonics); Polyphenol oxidase; Thermal; Thermodynamics; Thermosonic; Ultrasonic chemistry; Ultrasonics; Ultrasound
• ISSN: 1350-4177; 1873-2828
• DOI: 10.1016/j.ultsonch.2012.09.012

► Sonication and its background. ► Effect of temperature on mushroom PPO thermal stability. ► Thermal inactivation kinetics of mushroom PPO. ► The inactivation kinetics of PPO during thermosonication. ► Mechanisms of enzyme inactivation by ultrasound. The effect of thermal and thermosonic treatments on the inactivation kinetics of polyphenol oxidase (PPO) in mushroom (Agaricus bisporus) was studied in 55–75°C temperature range. In both the processes, the inactivation kinetics of PPO followed a first-order kinetics (R2=0.941–0.989). The D values during thermal inactivation varied from 112±8.4min to 1.2±0.07min while they varied from 57.8±6.1min to 0.88±0.05min during thermosonic inactivation at the same temperature range. The activation energy during thermal inactivation was found to be 214±17kJ/mol, while it was 183±32kJ/mol during thermosonic inactivation. The inactivating effect of combined ultrasound and heat was found to synergistically enhance the inactivation kinetics of PPO. The D values of PPO decreased by 1.3–3 times during thermosonic inactivation compared to the D values of PPO during thermal inactivation at the temperature range. Therefore, thermosonication can be further developed as an alternative to “hot break” process of mushroom.