Department of Chemistry and Biochemistry, Baylor University, Waco, Texas 76798, USA.
J Agric Food Chem. 2010 Mar 24;58(6):3251-8. doi: 10.1021/jf9033877.
Any valuation of a potential feedstock for bioprocessing is inherently dependent upon detailed knowledge of its chemical composition. Accepted analytical procedures for compositional analysis of biomass water-soluble extracts currently enable near-quantitative mass closure on a dry weight basis. Techniques developed in conjunction with a previous analytical assessment of corn stover have been applied to assess the composition of water-soluble materials in four representative switchgrass samples. To date, analytical characterization of water-soluble material in switchgrass has resulted in >78% mass closures for all four switchgrass samples, three of which have a mass closure of >85%. Over 30 previously unknown constituents in aqueous extracts of switchgrass were identified and quantified using a variety of chromatographic techniques. Carbohydrates (primarily sucrose, glucose, and fructose) were found to be the predominant water-soluble components of switchgrass, accounting for 18-27% of the dry weight of extractives. Total glycans (monomeric and oligomeric sugars) contributed 25-32% to the dry weight of extractives. Additional constituents contributing to the mass balance for extractives included various alditols (2-3%), organic acids (10-13%), inorganic ions (11-13%), and a distribution of oligomers presumed to represent a diverse mixture of lignin-carbohydrate complexes (30-35%). Switchgrass results are compared with previous analyses of corn stover extracts and presented in the context of their potential impact on biomass processing, feedstock storage, and future analyses of feedstock composition.
任何潜在的生物加工原料的评估都固有地依赖于其化学成分的详细知识。目前，用于生物质水溶性提取物成分分析的公认分析程序能够在干重基础上实现近乎定量的质量闭合。与先前对玉米秸秆的分析评估一起开发的技术已应用于评估四个代表性柳枝稷样品中水溶性物质的组成。迄今为止，对柳枝稷水溶性物质的分析表征导致所有四个柳枝稷样品的质量闭合度>78%，其中三个样品的质量闭合度>85%。使用各种色谱技术鉴定和定量了柳枝稷水提物中超过 78 种以前未知的成分。碳水化合物（主要是蔗糖、葡萄糖和果糖）被发现是柳枝稷中主要的水溶性成分，占提取物干重的 18-27%。总糖（单糖和寡糖）占提取物干重的 25-32%。对提取物质量平衡有贡献的其他成分包括各种糖醇（2-3%）、有机酸（10-13%）、无机离子（11-13%）以及一系列假定代表木质素-碳水化合物复合物的不同混合物的低聚物（30-35%）。将柳枝稷的结果与以前对玉米秸秆提取物的分析进行了比较，并根据它们对生物质加工、原料储存和未来原料成分分析的潜在影响进行了介绍。
