Dipartimento di Scienze degli Alimenti, Univ. di Udine, via Sondrio 2/A, 33100 Udine, Italy.
J Food Sci. 2013 Aug;78(8):E1183-7. doi: 10.1111/1750-3841.12216.
The effect of pulsed light on the inactivation of polyphenoloxidase (PPO) in model solutions was investigated focusing on the effect of enzyme concentration and total energy dose of the treatment. PPO inactivation increased with the dose of the treatment. Complete enzyme inactivation was achieved by pulsed light doses higher than 8.75 J cm(-2) . At low PPO concentrations (4 to 10 U), the enzyme resulted highly inactivated by pulsed light treatment. Further increase in enzyme units determined a progressive decrease in PPO inactivation. The latter was attributed to protein structural modifications including cleavage and unfolding/aggregation phenomena. PPO amounts higher than 10 U probably favoured enzyme conformations that were less prone to intermolecular rearrangements leading to inactivation.
研究了脉冲光对模型溶液中多酚氧化酶（PPO）失活的影响，重点研究了酶浓度和处理总能量剂量的影响。随着处理剂量的增加，PPO 的失活率增加。脉冲光剂量高于 8.75 J/cm(-2) 可实现完全酶失活。在低 PPO 浓度（4 至 10 U）下，脉冲光处理可使酶高度失活。进一步增加酶单位会导致 PPO 失活率逐渐降低。这归因于蛋白质结构的修饰，包括切割和展开/聚集现象。高于 10 U 的 PPO 可能有利于酶构象，这些构象不易发生导致失活的分子间重排。
