【摘要】 饱和水蒸气处理诱发枫桦变色的主要因子是饱和水蒸气的温度和抽提物。为了研究抽提物对枫桦诱发变色的作用,该文采用饱和水蒸气对原木粉和10种溶剂抽提过的枫桦心、边材木粉进行处理,测量其颜色变化,并用紫外光谱仪(UV-VIS)和气质联用仪(GC-MS)对饱和水蒸气处理前后木粉的甲醇抽提物的主要成分进行分析。结果表明:①经过抽提的枫桦木粉在经过饱和水蒸气处理后,颜色加深,但抽提溶剂不同,加深的程度也不同。②甲醇抽提物、苯-醇抽提物和热水抽提物中的部分成份对枫桦的诱发变色发挥了重要作用。③根据UV-VIS的检测结果可知,n→π*和π→π*跃迁引起的吸收带红移导致枫桦颜色变红。④通过GC-MS的分析可知,在饱和水蒸气处理过程中,部分物质发生反应使抽提物中的助色基团浓度降低,发色基团的浓度升高,从而使枫桦颜色加深。更多还原

【Abstract】 Reasons of Betula costata Trautv discoloration largely lie in the temperature of saturated steam and extractives of wood.In order to make clear the effects of extractives on induced discoloration of B.costata,wood powder,the sapwood and heartwood powder extracted by ten kinds of solvents were treated with saturated steaming,then the color of untreated and treated wood powder was measured.Main components in the methanol extractives of the untreated and treated wood powder were analyzed with UV-VIS and GC-MS.Results showed that: 1) the color of extracted powder tended to be dark after the saturated steaming treatment,however,degree of discoloration was different with respect to different solvents;2) some components in the methanol extractives,benzene-ethanol extractives and hot-water extractives had significant effects on the induced discoloration of B.costata;3) according to the results of UV-VIS test,red shifts of the absorption band resulted from n→π~* and π→π~* transition caused the color of wood powder to be red;4) results of GC-MS test indicated that the decrease of concentration of auxochromic groups and the increase of concentration of chromophoric groups due to chemical reactions during the saturated steaming treatment contributed much to the induced discoloration of B.costata.更多还原