Polyphenol oxidase inactivation and vitamin C degradation kinetics of Fuji apple quarters by high humidity air impingement blanching


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In this study, polyphenol oxidase (PPO) and vitamin C were used as the indicators of enzymes and nutrients to evaluate the apple quality during high humidity air impingement blanching (HHAIB) process. The PPO can be completely inactivated within 7 min at 90–120 °C and can retain relatively more vitamin C in the case of PPO fully inactivation. PPO inactivation followed zero-order kinetics model at 90 and 100 °C, and followed first-order fraction model at 110 and 120 °C. Activation energy (Ea) of PPO inactivation was between 11.61 and 13.66 kJ mol−1 by Arrhenius equation. Vitamin C degradation under all processing temperatures was well described by first-order model and its Ea value was 26.69 kJ mol−1. Therefore, the HHAIB process was proved to be an effective pretreatment for Fuji apple quarters to inactivate PPO fast and meanwhile to maintain produce quality.