Partial characterization and inactivation of peroxidases and polyphenol-oxidases of umbu-cajá (Spondias spp.)

A crude extract of Spondias spp. was evaluated for the influence of pH and temperature on the activity and stability of its peroxidases and polyphenol-oxidases. In order to evaluate the conditions for the inactivation of the enzymes by heat treatment and by addition of a reducing agent, a factorial...

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Detalles Bibliográficos
Autores: Silva,Cíntia Reis da, Koblitz,Maria Gabriela Bello
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2010
País:Brasil
Institución:Sociedade Brasileira de Ciência e Tecnologia de Alimentos (SBCTA)
Repositorio:Food Science and Technology (Campinas)
Idioma:inglés
OAI Identifier:oai:scielo:S0101-20612010000300035
Acceso en línea:http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0101-20612010000300035
Access Level:acceso abierto
Palabra clave:peroxidase
polyphenol-oxidase
Spondias spp.
inactivation
Descripción
Sumario:A crude extract of Spondias spp. was evaluated for the influence of pH and temperature on the activity and stability of its peroxidases and polyphenol-oxidases. In order to evaluate the conditions for the inactivation of the enzymes by heat treatment and by addition of a reducing agent, a factorial experimental design (n = 3) was employed using the Statistica (6.0) software package for data analysis. The optimal conditions found for peroxidases were: pH = 5.0 and temperature = 40 ºC, and for polyphenol-oxidases they were pH = 7.0 and temperature = 40 ºC. The peroxidases and polyphenol-oxidases were stable at all pH values tested (3.0 - 10.0) and maintained more than 60% of their activity at temperatures above 30 and 40 ºC, respectively. To achieve the total inactivation of these enzymes, two alternatives can be suggested: incubation at 92 ºC for 3.15 minutes with 200 mg.L-1 of ascorbic acid or incubation at 96 ºC for 2.80 minutes with 100 mg.L-1 of ascorbic acid.