研究了不同工艺条件下竹子热水预抽提过程中主要糖类组分的溶出率,总糖和戊糖占抽提液中固形物的比例,以及糠醛、羟甲基糠醛的生成随H因子的变化规律.结果表明：为了获取最大量的糖、减少糠醛（F）和羟甲基糠醛（HMF）的生成量,lgH应控制在3.2～3.4的范围内;在获得相同最大量糖的前提下,热水预抽提的最高温度不应超过160℃;当lgH低于3.2～3.4的范围时,糖的溶出率较低;高于此范围,部分糖降解生成F和HMF,总糖占抽提液固形物的比例和糖组分溶出率下降;在总糖溶出率达到最大值时,相同H因子作用下,温度超过160℃会导致糖降解生成的F和HMF增多.关键词：竹子半纤维素;热水预抽提;H因子;糖溶出率;糠醛;羟甲基糠醛

This paper deals with the relationships between the H-factor and the dissolving rates of main saccharides,the ratio of total saccharides and pentose to the total solid as well as the concentration of furfural（F） and hydroxymethylfurfural（HMF） in the hot-water preextracted liquor of bamboo in different conditions.The results show that（1） for the purpose of obtaining more saccharides and reducing the conversion of saccharides to F and HMF,the lgH value during the preextraction should be controlled within the range of 3.2～3.4,and the maximum preextraction temperature should not be higher than 160℃;（2） when the lgH value is lower than 3.2,the dissolving rates of saccharides decrease,while when it is higher than 3.4,some saccharides convert to F and HMF,and the dissolving rates as well as the ratio of total saccharides and pentose to the total solid decrease;and（3） at the maximum dissolving rate and the same H-factor,more saccharides may convert to F and HMF at a higher temperature（160℃）.