Characterization of polyphenol oxidase from blueberry (Vaccinium corymbosum L.).
Food Chem
; 218: 216-220, 2017 Mar 01.
Article
em En
| MEDLINE
| ID: mdl-27719900
ABSTRACT
Polyphenol oxidase (PPO) was extracted and characterized from high-bush blueberries. PPO showed an optimum activity at pH 6.1-6.3 and 35°C, with the enzyme showing significant activity over a wide temperature range (25-60°C). Catechol was the most readily oxidized substrate followed by 4-methylcatechol, DL-DOPA, and dopamine. Blueberry PPO showed a Km of 15mM and Vmax of 2.57 ΔA420nm/min×10-1, determined with catechol. PPO was completely inactivated in 20min at 85°C, however, after 30minat 75°C it showed about 10% residual activity. Thermal treatment at 55 and 65°C for 30min resulted in the partial inactivation of PPO. Ascorbic acid, sodium diethyldithiocarbamic acid, L-cysteine, and sodium metabisulfite were effective inhibitors of PPO at 1.0mM. Benzoic acid and cinnamic acid series inhibitors showed relatively weak inhibition of PPO (21.8-27.6%), even at as high as 2.0mM concentration.
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Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Catecol Oxidase
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Cor
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Mirtilos Azuis (Planta)
Idioma:
En
Ano de publicação:
2017
Tipo de documento:
Article