Partial Characterization of a New Peptide from Ivorian Red Onion that Inhibits Polyphenol Oxidase and Enzymatic Browning of Edible Yam (Dioscorea cayenensis-rotundata cv LongbÔ )

Sophie N. Gnangui; Sebastien L. Niamke; Lucien P. Kouame

Partial Characterization of a New Peptide from Ivorian Red Onion that Inhibits Polyphenol Oxidase and Enzymatic Browning of Edible Yam (Dioscorea cayenensis-rotundata cv LongbÔ )

Sophie N. Gnangui , Sebastien L. Niamke and Lucien P. Kouame
* Author for corresponding; e-mail address: kouame_patrice@yahoo.fr
Volume: Vol.37 No.3 (SEPTEMBER 2010)
Research Article
DOI:
Received: 26 October 2009, Revised: -, Accepted: 17 August 2010, Published: -

Citation: Gnangui S.N., Niamke S.L. and Kouame L.P., Partial Characterization of a New Peptide from Ivorian Red Onion that Inhibits Polyphenol Oxidase and Enzymatic Browning of Edible Yam (Dioscorea cayenensis-rotundata cv LongbÔ ) , Chiang Mai Journal of Science, 2010; 37(3): 464-475.

Abstract

The enzymatic browning of the yam was retarded by addition of fresh onion extract. The maximal activity of polyphenol oxidase inhibitor was increased with higher fresh onion extract concentrations. The inhibitor was a peptide and inhibited the polyphenol oxidase non-competitively. It was stable at pH 6.6 in phosphate buffer for 120 min at 35^oC. Rapid inactivation occurred from 50 to 60^oC and it was completely inactivated at 65^oC after 1h30 min incubation. From 40 to 60^oC, the activation energy value for thermal inactivation of the peptide was calculated to be 109.93kJ/mol. The D-values showed that the thermal treatment had more influence on the inactivation of the peptide.

Keywords: enzymatic browning, inhibitory effect, polyphenol oxidase, onion, peptide, yam

Chiang Mai Journal of Science

1,647

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Q3 1.3

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