F. Richard-Forget, Frédéric Gauillard
Jul 16, 1997
Citations
8
Influential Citations
231
Citations
Quality indicators
Journal
Journal of Agricultural and Food Chemistry
Abstract
To clarify the role of pear peroxidase (POD) in enzymatic browning, oxidation of 4-methylcatechol, chlorogenic acid, and (−)-epicatechin catalyzed by purified polyphenol oxidase (PPO), purified POD, or combinations of the two enzymes was followed by HPLC. It was shown that pear POD had no oxidative (oxygen dependent) activity. However, in presence of PPO, POD enhanced the phenol degradation. Moreover, when PPO was entirely inhibited by NaCl after different oxidation times, addition of POD led to a further consumption of the phenolic compound. Two mechanisms have been proposed to explain this additional consumption. First, our results have demonstrated that, whatever the substrate used, PPO oxidation generated H2O2, the amount of which varies with the phenolic structure. Second, quinonic forms are used by POD as peroxide substrate. These two mechanisms associated with the kinetic properties of pear PPO and POD are consistent with an effective involvement of pear POD in enzymatic browning. Keywords: Enzymat...