Abstract Pressurized hot water pretreatment was performed on softwood (SW) and hardwood (HW) chips following the same conditions (1 h at 170 °C) in order to partly hydrolyse hemicelluloses. The complete characterization of these sugar enriched autohydrolysates (AH) being rather complex, two different purification methods were conducted. Nanofiltration (NF) 1kDa membrane and ultrafiltration (UF) 3 and 5kDa membranes were used to separate oligosaccharides (OS) from undesired compounds and for their molar mass fractionation. Granulated activated charcoal (GAC) adsorption was also used for hydrolysates detoxification. The chemical nature of OS and side charge groups vary significantly depending of the fractions obtained, e. g. xylans' chain length is positively correlated with the degree of acetylation. UF at 5kDa allows for the total separation of galactoglucomannans (GGMs) from xylans, in SW AH, however, this result was not achieved with HW. From the acid soluble lignin (ASL) removal point of view, membrane filtration from 1kDa is more efficient than activated carbon treatment concerning HW AH, on the contrary to SW AH. Regarding the lignin to OS ratio, for both species, GAC leads to a better sugar purity.

中文翻译：

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一种硬木和软木生产水溶性低聚糖的多步纯化方法

摘要 在相同条件下（170 °C 下 1 小时）对软木 (SW) 和硬木 (HW) 木片进行加压热水预处理，以部分水解半纤维素。这些富含糖的自水解物 (AH) 的完整表征相当复杂，因此进行了两种不同的纯化方法。纳滤 (NF) 1kDa 膜和超滤 (UF) 3 和 5kDa 膜用于将低聚糖 (OS) 与不需要的化合物分离并进行摩尔质量分馏。颗粒状活性炭 (GAC) 吸附也用于水解物解毒。OS 和侧电荷基团的化学性质根据获得的分数而显着变化，例如木聚糖的链长与乙酰化程度呈正相关。5kDa 的超滤允许在 SW AH 中将半乳葡甘露聚糖 (GGM) 与木聚糖完全分离，但是，使用 HW 无法实现这一结果。从酸溶性木质素 (ASL) 去除的角度来看，对于 HW AH，与 SW AH 相反，1kDa 的膜过滤比活性炭处理更有效。关于木质素与 OS 的比率，对于这两个物种，GAC 导致更好的糖纯度。