Polyphenol oxidase from yacon roots (Smallanthus sonchifolius)

Página do item simplificado
dc.contributor.authorNeves, Valdir Augusto
dc.contributor.authorda Silva, Maraiza Aparecida
dc.contributor.institutionUniversidade Estadual Paulista (Unesp)
dc.date.accessioned2014-05-20T13:23:36Z
dc.date.available2014-05-20T13:23:36Z
dc.date.issued2007-03-21
dc.description.abstractPolyphenol oxidase (E.C. 1.14.18.1) (PPO) extracted from yacon roots (Smallanthus sonchifolius) was partially purified by ammonium sulfate fractionation and separation on Sephadex G-100. The enzyme had a molecular weight of 45 490 +/- 3500 da and K-m values of 0.23, 1.14, 1.34, and 5.0 mM for the substrates caffeic acid, chlorogenic acid, 4-methylcatechol, and catechol, respectively. When assayed with resorcinol, DL-DOPA, pyrogallol, protocatechuic, p-coumaric, ferulic, and cinnamic acids, catechin, and quercetin, the PPO showed no activity. The optimum pH varied from 5.0 to 6.6, depending on substrate. PPO activity was inhibited by various phenolic and nonphenolic compounds. p-Coumaric and cinnamic acids showed competitive inhibition, with K-i values of 0.017 and 0.011 mM, respectively, using chlorogenic acid as substrate. Heat inactivation from 60 to 90 degrees C showed the enzyme to be relatively stable at 60-70 degrees C, with progressive inactivation when incubated at 80 and 90 degrees C. The E-a (apparent activation energy) for inactivation was 93.69 kJ mol(-1). Sucrose, maltose, glucose, fructose, and trehalose at high concentrations appeared to protect yacon PPO against thermal inactivation at 75 and 80 degrees C.en
dc.description.affiliationUniv Estadual Paulista, UNESP, FCF Ar, Dept Alimentos & Nutr,Lab Bioquim Alimentos, BR-14801902 Araraquara, SP, Brazil
dc.description.affiliationUnespUniv Estadual Paulista, UNESP, FCF Ar, Dept Alimentos & Nutr,Lab Bioquim Alimentos, BR-14801902 Araraquara, SP, Brazil
dc.format.extent2424-2430
dc.identifierhttp://dx.doi.org/10.1021/jf063148w
dc.identifier.citationJournal of Agricultural and Food Chemistry. Washington: Amer Chemical Soc, v. 55, n. 6, p. 2424-2430, 2007.
dc.identifier.doi10.1021/jf063148w
dc.identifier.issn0021-8561
dc.identifier.urihttp://hdl.handle.net/11449/7145
dc.identifier.wosWOS:000244867300053
dc.language.isoeng
dc.publisherAmer Chemical Soc
dc.relation.ispartofJournal of Agricultural and Food Chemistry
dc.relation.ispartofjcr3.412
dc.relation.ispartofsjr1,269
dc.rights.accessRightsAcesso restrito
dc.sourceWeb of Science
dc.subjectyacon rootspt
dc.subjectSmallanthus sonchifoliuspt
dc.subjectpolyphenol oxidasept
dc.subjectpurificationpt
dc.subjectkineticspt
dc.subjectinhibitorspt
dc.subjectthermal inactivationpt
dc.subjectsugar protectionpt
dc.titlePolyphenol oxidase from yacon roots (Smallanthus sonchifolius)en
dc.typeArtigo
dcterms.licensehttp://pubs.acs.org/paragonplus/copyright/jpa_form_a.pdf
dcterms.rightsHolderAmer Chemical Soc
unesp.campusUniversidade Estadual Paulista (Unesp), Instituto de Química, Araraquarapt

Arquivos

Licença do Pacote
Agora exibindo 1 - 1 de 1
Nenhuma Miniatura disponível
Nome:
license.txt
Tamanho:
1.71 KB
Formato:
Item-specific license agreed upon to submission
Descrição:

Coleções

Artigos - Bioquímica e Tecnologia - IQ