Extraction of arabinoxylans from wheat bran using hydrothermal processes assisted by heterogeneous catalysts

Abstract

The extraction/hydrolysis process of arabinoxylans from destarched wheat bran was studied in this work using different mesoporous silica supports and the corresponding RuCl3-based catalysts. The effects of temperature, time, catalyst supports and ruthenium catalysts were investigated and discussed in terms of the arabinoxylans extraction yield and their polymerization degree. Relatively high temperatures (180 ºC), short extraction times (10 minutes) and RuCl3 supported on Al-MCM-48 led to a high amount of arabinoxylans extracted (78%) with a low molecular weight (9 KDa). Finally, a relation between the operating conditions, the arabinoxylans extraction yield and the molecular weight was stablished based on the obtained results. Abbreviation: AXs, arabinoxylans; DWB, destarched wheat branKeywords: Hemicelluloses fractionation, wheat bran, arabinoxylans, heterogeneous catalysis, hydrothermal process, biomass Chemical compounds studied in this articleXylose (PubChem CID: 135191); Arabinose (PubChem CID: 439195) Highlights:-Effects of ruthenium catalyst, temperature, time and catalyst support are discussed -RuCl3-based catalysts show good activity for the arabinoxylans extraction from wheat bran -Liquid extracts are characterized in terms of sugars, molecular weight and purity

From Biomass to Sugar Alcohols: Purification of Wheat Bran Hydrolysates Using Boronic Acid Carriers Followed by Hydrogenation of Sugars over Ru/H-ZSM-5

“…the fractionation of biomass (wheat bran) to isolate the hemicelluloses and their further hydrolysis into monomeric C5 sugars. 14,15 Since the content of monosaccharides in the hydrolysate is quite low (of ca. 0.8 wt.%), additional concentration and purification stages to obtain sugars-rich hydrolysates must be considered before the hydrogenation process.…”

Development of an integrated and green biorefinery from winery waste. Application to wine lees and grape stems

“…The composition of GS was determined according to the Laboratory Analytical Procedure (LAP) for biomass analysis provided by the National Renewable Energy Laboratory (NREL) ( a Sluiter et al, 2008). This procedure has been previously described in prior works of our group (Gallina, Cabeza, et al, 2018;Sánchez-Bastardo et al, 2017).…”

“…To carry out the experimental procedure 13g of dried stems were introduced in the extractor vessel with 130mL of distilled water. A relative high suspension concentration ( 100g•L -1 ) was chosen in comparison to previous works of the group (Sánchez-Bastardo et al, 2017) due to the lower initial content of the holocellulose in the raw material used in this work.. Then the extractor vessel was closed and put in a stirring plate at 1,200rpm. Once the desired temperature was achieved the operating time started to run.…”

“…Results showed that assays at 210 °C led to the highest recovery of carbohydrates (85% of total amount of initial carbohydrates). Additionally, Sánchez-Bastardo et al (Sánchez-Bastardo, Romero, & Alonso, 2017) were able to recover high amount of arabinoxylans (58-71%) from wheat bran using hydrothermal processes assisted by heterogeneous catalysts. Similarly, the combination of carbon dioxide and water has been also demonstrated to be a suitable option for biomass conversion into sugars (Relvas, Morais, & Bogel-Lukasik, 2015).…”

Development of a microwave pretreatment for the extraction of active compounds from natural by products

“…Several biomass fractionation techniques have been deeply studied. The most extended ones are acid or alkaline hydrolysis, pyrolysis, enzymatic hydrolysis, gasification, heterogeneous and hydrothermal hydrolysis (Tekin et al, 2014, Demirbas, 2010, Sánchez-Bastardo et al, 2017. Among all, hydrothermal fractionation stands out, since it just requires water and temperature to degrade lignocellulosic biomass.…”