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Ascorbic Acid and 4‐Hexylresorcinol Effects on Pear PPO and PPO Catalyzed Browning Reaction
Author(s) -
Arias E.,
González J.,
Oria R.,
LopezBuesa P.
Publication year - 2007
Publication title -
journal of food science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.772
H-Index - 150
eISSN - 1750-3841
pISSN - 0022-1147
DOI - 10.1111/j.1750-3841.2007.00484.x
Subject(s) - browning , ascorbic acid , pear , chemistry , enzyme , catalysis , substrate (aquarium) , biochemistry , reducing agent , food science , stereochemistry , organic chemistry , botany , biology , ecology
The effects of ascorbic acid (AA) and 4‐hexylresorcinol (4‐HR) on 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 of PPO inactivating 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.