Resumo

NUNEZ, Carlos E.. Distribución Radial de Polifenoles en Troncos de Eucalyptus grandis: Radial Distribution of Polyphenols in the Stems of Eucalyptus grandis. Rev. cienc. tecnol. [online]. 2009, n.11, pp.20-25. ISSN 1851-7587.

Polyphenols color pulps and may interfere in the pulping process. No research works on the distribution in E. grandis are known. The radial variation of polyphenol concentration in five E. grandis individuals aged 7 and 18 years old was measured. Azeotropic ethanol was used for the extraction of the wood reduced to shaving. Results are in accordance with the general pattern cited in the bibliography. In 7 year old trees, there were relatively more polyphenols in the sapwood than in those of 18. No significant differences were noticed in the UV absorption spectrograms among the rings of the 18 year-old trees. A different spectrogram in one aged 7 would indicate the existence of hybridation. The concentration of poliphenols around one of the knots was four times as high than in the wood of the same age.

Palavras-chave : Eucalyptus grandis; Polyphenols; Chemical composition; Flavonoids; Ellagic acid; (Thesaurus IPST 1990).

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