Maximization of monomeric C5 sugars from wheat bran by using mesoporous ordered silica catalysts.

The hydrolysis process of a real fraction of arabinoxylans derived from wheat bran was studied. The influence of catalyst type and loading, reaction time and different metal cations were discussed in terms of the hydrolysis yield of arabinose and xylose oligomers as well as the formation of furfural as degradation product. A high yield of arabinoxylans into the corresponding monomeric sugars (96 and 94% from arabino- and xylo-oligosaccharides, respectively) was obtained at relatively high temperatures (180°C) and short reaction times (15min) with a catalyst loading of 4.8g of RuCl3/Al-MCM-48 per g of initial carbon in hemicelluloses.

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

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°C), short extraction times (10min) and RuCl3 supported on Al-MCM-48 led to a high amount of extracted arabinoxylans (78%) with a low molecular weight (9kDa). Finally, a relation between the operating conditions, the arabinoxylans extraction yield and the molecular weight was stablished based on the obtained results.