Journal of Nutrition & Food Sciences

Journal of Nutrition & Food Sciences
Open Access

ISSN: 2155-9600

+44 7480022449

Paul Chidoka Chikezie

Paul Chidoka Chikezie

Owerri
Nigeria

Publications
  • Research Article
    Kinetic Studies of Polyphenol Oxidase from White Yam (Dioscorea rotundata Poir) Tuber
    Author(s): Paul Chidoka ChikeziePaul Chidoka Chikezie

    Enzymatic browning is engendered by conversion of monophenols (cresolase activity) and ortho-diphenols (catecholase activity) to reactive ortho-quinones in the presence of molecular oxygen by polyphenol oxidases (PPOs). The present study ascertained the inhibition kinetics of PPO extracted from Dioscorea rotundata tuber in the presence of non-toxic sulfhydryl amino acid (L-cysteine) and appraised other connecting kinetic and thermodynamic properties of D. rotundata PPO (DR-PPO). DR-PPO was extracted and purified by (NH4)2SO4 precipitation, ultrafiltration and dialysis. Thermodynamic parameters and DR-PPO activity were measured by standard methods. Kinetic analyses showed that 4.0 mM L-cysteine displayed non-competitive inhibition prototype with DR-PPO experimental substrate. The affinity of L-cysteine for DR-PPO inhibitor binding site was ≈ 25 folds greater than that of catechol.. Read More»
    DOI: 10.4172/2155-9600.1000355

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