Ascorbic acid and 4-hexylresorcinol effects on pear PPO and PPO catalyzed browning reaction
Arias, Esther | González Buesa, Jaime | Oria, R. | Lopez-Buesa, P.
The effects of the ascorbic acid (AA) and 4-hexylresornicol (4-HR) on the pear polyphenoloxidase (PPO) activity and stability have been investigated in vitro. AA does not interact directly with PPO but prevents browning by reducing oxidized substrates. The 4-HR exerts a dual role on PPO. If no substrates are present, it interacts preferably with the deoxy form off PPO in activating it. If substrates and 4-HR are both present they compete for the catalytic site. The 4-HR behaves then as a canonical enzyme inhibitor, binding to the met form of PPO. Simultaneous addition of 4-HR and AA has synergistic inhibition or inactivatory effects depending on the presence or the absence of PPO substrates.
Показать больше [+] Меньше [-]Este estudio fue financiado por CICyT (Proyecto AGL 2001-1766) y por el MEC, que otorgó una beca a E. Arias para llevar a cabo esta investigación.
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