Characterization of polyphenoloxidase (PPO) extracted from 'Jonagored' apple

• Tipo: Artigo em Revista Científica Internacional
• Data: 2001

Autores

Rocha, Ada (Autor) FCNAUP; Morais, AMMB (Autor) Outra

Revista

Título: Food Control

Vol. 12 Nº 2

Páginas: 85-90

ISSN: 0956-7135

Editora: Elsevier

Indexação

ISI Web of Knowledge - 78 Citações

Scopus - 86 Citações

Outras Informações

ID Authenticus: P-000-W81

DOI: 10.1016/s0956-7135(00)00026-8

Abstract (EN): Polyphenoloxidase (PPO) was extracted from apple (cv. Jonagored) with addition of 2% PVP and 0.25% Triton X100 to the extraction buffer containing phenolic adsorbents. Experiments were performed to evaluate the affinity and specificity towards several substrates. 'Jonagored' apple PPO was found to have higher specificity (lower K-m) towards L-dopa, 4-methylcatechol and (+) catechin than other phenols tested, but the highest activity level was obtained with p-cresol. The ratio V-max/K-m indicates that p-cresol followed by L-dopa and 4-methylcatechol are the best substrates for 'Jonagored' apple PPO. The enzyme activity showed two pH optima, at 5.0 and 7.5, at room temperature, with the main peak at pH 7.5 and the secondary one at pH 5.0 when catechol was the substrate.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 6