文献类型：期刊文献

中文题名：黑木相思木材化学组分对其颜色株内变异的影响

英文题名：Effect of chemical components on wood color variation of Acacia melanoxylon

作者：周凡[1] 高鑫[1] 付宗营[1] 裘珍飞[2] 周永东[1]

第一作者：周凡

机构：[1]中国林业科学研究院木材工业研究所,北京100091;[2]中国林业科学研究院热带林业研究所,广东广州510520

年份：2021

卷号：41

期号：6

起止页码：42-50

中文期刊名：中南林业科技大学学报

外文期刊名：Journal of Central South University of Forestry & Technology

收录：CSTPCD;;北大核心:【北大核心2020】；CSCD:【CSCD_E2021_2022】；

基金：中央级公益性科研院所基金项目(CAFYBB2018ZB004);广东省林业科技创新项目(2018KJCX004)。

语种：中文

中文关键词：黑木相思;木材颜色;抽出物;木质素;化学成分

外文关键词：Acacia melanoxylon,wood color,extractive;lignin;chemical constituent

分类号：S781.41

摘要：【目的】黑木相思木材颜色美丽,是优良的装饰用材。研究黑木相思化学组分(抽出物和木质素)对木材颜色株内(径向和纵向)变异的影响,可为探讨树木生长过程颜色形成以及木材加工利用过程颜色调控提供依据。【方法】采用CIELab颜色系统对黑木相思株内不同径向和纵向位置木材的颜色参数(明度色品指数L^(*),红绿色品指数a^(*),黄蓝色品指数b^(*))进行表征。采用水、苯醇和1%氢氧化钠溶剂抽提测定木材抽出物含量。采用硫酸水解法测定木材酸不溶木质素含量。采用傅里叶红外光谱(FTIR)和气相色谱质谱联用(GC-MS)方法对木材抽出物的化学成分进行分析。【结果】1)径向上,由心材内层向心材外层,L^(*)和b^(*)逐渐减小,而a^(*)无明显变化规律;继续向外至边材,L^(*)明显增加,a^(*)减小,b^(*)微减小。沿纵向向上,心材L^(*)和a^(*)微降低,b^(*)无明显变化规律;边材b^(*)微增加,L^(*)和a^(*)无明显变化规律。黑木相思木材株内颜色差异整体上主要归结于L^(*)和a^(*)的变化。2)L^(*)与冷水、苯醇、热水和1%氢氧化钠抽出物在0.01层上以及与木质素在0.05层上均相互呈显著负相关;a^(*)与各抽出物和木质素在0.01层上呈显著正相关。L^(*)和a^(*)与抽出物的相关性大于与木质素,且与苯醇抽出物的相关性最强。苯醇抽出物的颜色深浅与其对应木材的颜色呈现一致性。3)黑木相思株内不同部位木材苯醇抽出物的主要化学成分相似,但相对含量存在差异。这些主成分为苯酚类、醇类和酸酯类化合物,含有丰富的羟基、羰基和苯环等结构。边材的苯酚类物质相对更多;心材的醇类物质相对更多;心材外层比心材内层的酸酯类物质相对更多。【结论】黑木相思木材颜色在株内的变异主要体现为木材颜色对黑色和红色偏向程度的差异,差异源主要是心材和边材,其次是不同部位心材。黑木相思的木材颜色与其抽出物相关性明显。采用苯醇抽提可获取黑木相思木材中的显色成分,可能为苯酚类、醇类和酸酯类化合物。树木生长过程,木材抽出物伴随材龄变化而积累,抽出物中各显色组分的复杂反应同时发生,最终导致黑木相思木材颜色的株内变异。
【Objective】The wood of Acacia melanoxylon with a strong color appearance has been considered as superior decorative timber.The effects of chemical components(extractive and lignin)on the variation of wood color within the tree(radial and longitudinal)of this species were studied.The results can provide the theoretical basis for the understanding of wood color formation during tree growth and color regulation during wood utilization.【Method】The color parameters(lightness L^(*),green-red axis value a^(*),blue-yellow axis value b^(*))of wood at different radial and longitudinal positions were determined by the CIELab color system.The amounts of extractives from wood were determined using water,benzene-ethanol,and 1%sodium hydroxide as solvents.The acid-insoluble lignin content of wood was followed the sulfuric acid hydrolysis procedure.The Fourier transform infrared spectroscopy(FTIR)and gas chromatography-mass spectrometry(GC-MS)analyses were carried out to identify the chemical constituents of extractives.【Result】1)The L^(*)and b^(*)decrease from the inner to the outer heartwood,while a^(*)has no obvious change.The sapwood has higher L^(*)than heartwood and lower a^(*),while the b^(*)is similar.In the longitudinal direction,for heartwood,the L^(*)and a^(*)exhibit the slight decrease tendency upwards while b^(*)has no obvious change,and for sapwood,the b^(*)increases slightly while the L^(*)and a^(*)have no obvious change.The L^(*)and a^(*)contribute mainly to the total variation of wood color within the tree.2)The L^(*)has the significant negative correlations with the extractives(cold water,hot water,benzene-ethanol,1%sodium hydroxide)and lignin at 0.01 and 0.05 confidence level,respectively.The a^(*)has the significant positive correlations with various extractives and lignin at 0.01 confidence level.The L^(*)and a^(*)has greater correlation with extractives than that with lignin,and the correlation with the benzene-ethanol extractives is the strongest among the four extractives.Moreover,the color of the benzene-ethanol extractives is consistent with the appearance of the wood from which it is derived.3)The main chemical constituents of benzene-ethanol extractives from wood at different positions are similar,but the relative contents of the constituents are different.The constituents are mainly phenolic,alcohol,and fatty acid ester compounds containing abundant hydroxyl,carbonyl,and benzene-containing functional groups structures.The sapwood contains relatively more phenolic substances.The heartwood contains relatively more alcohol substances.The inner layer contains relatively more acid ester substances than the outer layer of heartwood.【Conclusion】The wood color variation within the tree is mainly the different deviation degree of the black and red color.The heartwood and sapwood is the main source,and then is the heartwood at different positions.The color of Acacia melanoxylon wood is significantly correlated with its extractives.The chromogenic substance in Acacia melanoxylon wood that may be mainly the phenolic,alcohol,and fatty acid ester compounds can be extracted effectively by benzene-ethanol.The extractives accumulate during tree growth,and the complex reactions of the chemical constituents of extractives take place simultaneously with the change of wood age,which finally leads to the variation of wood color within the tree.