Influence of Extractives on the Analysis of Herbaceous Biomass

Abstract

The consequences of extracting switchgrass, corn stover, and fescue feedstocks with either 95% ethanol or hot water prior to the chemical characterization of the feedstock have been determined. Glycans (glucan and xylan), Klason lignin, acid soluble lignin, uronic acids, acetyl groups, protein, and ash analyses were done on each feedstock. Extraction with 95% ethanol or hot water significantly reduced the measured Klason lignin values of all the feedstocks. Ethanol extractions reduced the apparent glucan content of two of the feedstocks, fescue and switchgrass. Extractions with hot water reduced the apparent glucan content of all the feedstocks. The apparent content of other components in the feedstock, such as ash and protein, was also reduced as a result of doing solvent extractions. The results indicate that more accurate estimates of the true lignin and cellulose content of a feedstock are obtained if extractives are removed from the feedstock prior to the analysis. However, in some cases the analysis of extracted feedstocks resulted in lower values for the total carbohydrate content of those feedstocks. This parameter is critical when evaluating these feedstocks for biomass-to-ethanol processes. Keywords: Corn stover; switchgrass; fescue; cellulose; lignin; extractives.

High-Throughput Profiling of the Fiber and Sugar Composition of Sugarcane Biomass

“…Figure 3 presents predicted results using the developed models for the four biomass components. This data represents the potential sugar sources (mostly from hexose-glucose and pentose-xylose from cellulose and hemicellulose) in the sample to be used for biofuel production, as well as the recalcitrant challenge (from lignin content) of the biomass source [37,38]. The extractives, on the other hand, indicate the total amount water-and ethanol-soluble substances in the pressed fiber samples, including juice sugars not extracted during pressing.…”

“…The negative correlation between extractives and fiber content could likely be due to the different ability to retain juice of the low and the high fiber samples. For the accuracy of fiber characterization, the extractives need to be removed prior to composition analysis [38]. The extractive content cannot be used as a trait for assessing biomass for genetic studies, since it depends on the juice extraction method used to generate pressed fiber samples.…”

Comparison of high temperature chars of wheat straw and rice husk with respect to chemistry, morphology and reactivity

“…The compositional analysis of the biomass (cellulose, hemicellulose, acid-soluble lignin, acid-insoluble lignin, protein and extractives) was conducted according to NREL technical reports [22e24] and Thammasouk et al [25]. The water-ethanol extraction was performed on wheat straw and rice husk which contained a high level of hydrophilic and lipophilic extractable compounds, according to the procedure described in the Supplemental material [25].…”

“…The water-ethanol extraction was performed on wheat straw and rice husk which contained a high level of hydrophilic and lipophilic extractable compounds, according to the procedure described in the Supplemental material [25].…”

The Utilization of Soybean Straw. I. Fiber Morphology and Chemical Characteristics

“…They are present in different raw materials (Hames 2009). Total water and/or benzene-ethanol soluble materials are typically quantified gravimetrically and considered as extractives (Thammasouk et al 1997;Chen et al 2007). As indicated in Table 3, the amounts of extractives from the stem and root were similar, but much lower than the pod.…”