Relationship Between Wood Color Parameters Measured by the CIELab System and Extractive and Phenol Content in Acacia mangium and Vochysia guatemalensis from Fast-Growth Plantations

Abstract

: The heterogeneity of color distribution between sapwood and heartwood limits the market for wood from fast-growth plantations of tropical species. Wood color is associated with wood extractives contents. This study presents the relationship between wood color parameters measured by the CIELab color system and total amount of extractives and phenolic-type extractives in ethanol-toluene and hot water extracts of wood from two fast-growth plantation species. The results demonstrated that the difference in sapwood and hardwood color in Vochysia guatemalensis and Acacia mangium is caused by lower concentrations of extractives in sapwood of both species. Additionally, variations in total extractive and phenolic content have different effects on the color parameters (L*, a* and b*) of both species studied. In Vochysia guatemalensis wood, parameter L* decreases as total extractive and phenolic content increases; however, parameter a* increases as the content of extractives and phenols increases. In Acacia mangium, the amount of phenols showed no relationship with the color parameters. The ethanol-toluene total extractive content, however, shows a relationship with several color parameters. An increase in the content of total extractives in water and ethanol-toluene increases parameter a*, but decreases parameter L*.

Decay resistance of four fast-growing Eucalypts wood exposed to three types of fields

“…That possibly occurs due to the oxidation reactions and depolymerization of extractives in the formation of heartwood (Moya et al 2012), since ΔE of juvenile and mature wood was similar in the first 180 days of exposure, which indicate that both content and constitution of lignin are not related to this color difference.…”

“…The color of natural wood can vary due to its extractives, such as fatty acids and steroids, an aspect that can be considered for heartwood and sapwood, and well as juvenile and mature wood (Prinisha 2011, Moya et al 2012). …”

Relationship Between Wood Colour of Seven Tropical Hardwood Species and Formaldehyde Emission of Plywood

“…The difference in formaldehyde emission and content from different wood species could be attributed to the difference in extractive content [4][5]. The cell wall chemical content and extractive content of the seven wood species are displayed in Table 4.…”

Susceptibility of Thermo-Mechanically Modified Scots Pine (Pinus Sylvestris L.) Sapwood and Heartwood to Colour Change under the Influence of Ultraviolet Radiation

“…The colour of wood also depends on habitat conditions. Depending on the type and content of extractives, particular wood species show different susceptibility to colour change under the infl uence of ultraviolet radiation (Pandey, 2005; Persze and Tolvaj, 2012;Moya, et al 2012).…”