Inhibition kinetics of polyphenol oxidase by glutamic acid

Authors: Doğan, Serap; Turan, Pınar; Doğan, Mehmet; Alkan, Mahir; Arslan, Oktay

Source: European Food Research and Technology A, Volume 225, Number 1, May 2007 , pp. 67-73(7)

Publisher: Springer

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Abstract:

The inhibition of polyphenol oxidase (PPO) by glutamic acid was investigated. Application of different concentrations of glutamic acid to mushroom solution and Ocimum basilicum L. extract showed that glutamic acid appeared to be an effective browning inhibitor. Glutamic acid showed uncompetitive inhibition for mushroom and Ocimum basilicum L. polyphenol oxidases using 4-methylcatechol as a substrate, for mushroom PPO using catechol as a substrate and for Ocimum basilicum L. polyphenol oxidase using pyrogallol as a substrate; mixed-type inhibition for mushroom polyphenol oxidase using pyrogallol as a substrate; and non-competitive inhibition for Ocimum basilicum L. polyphenol oxidase using catechol as a substrate. Furthermore, sodium azide was used as an inhibitor for comparison with the inhibition potency of glutamic acid. It was found that glutamic acid was a more power inhibitor than sodium azide. The type of inhibition observed depended on the substrate, inhibitor and enzyme source used.

Keywords: Polyphenol oxidase; Glutamic acid; Mushroom; Ocimum basilicum L; Inhibition

Document Type: Research article

DOI: http://dx.doi.org/10.1007/s00217-006-0383-0

Affiliations: 1: Email: sdogan@balikesir.edu.tr

Publication date: 2007-05-01