ENZYMATIC PROCESSING OF CRUDE XYLOOLIGOMER SOLUTIONS OBTAINED BY AUTOHYDROLYSIS OF EUCALYPTUS WOOD

Abstract

ABSTRACT Liquors from the aqueous processing of Eucalyptus wood, containing soluble xylan-degradation products (mainly substituted xylooligomers) were subjected to the action of commercial enzyme complexes (Celluclast, Bioxilanasa-AXC, EconaseR HC 400, Cellulase T 4 and Hemicellulase 90) containing endo-xylanase, xylobiase and acetyl-xylan-esterase activities to assess their suitability to obtain either xylose-containing solutions (useful as fermentation media) or low-DP xylooligosaccharides (useful as food additives). Under selected conditions, the Celluclast, Bioxilanasa-AXC, EconaseR HC 400 and Cellulase T 4 complexes were able to convert into xylose up to 90% of the substituted xylooligosaccharides present in the autohydrolysis liquors. The enzyme Hemicellulase 90 allowed the conversion of up to 67% of the initial substituted xylooligosaccharides into low-DP oligosaccharides. The most remarkable finding was that a significant concentration of DP2 oligomers (that could be incorporated into functional foods as prebiotic ingredients) was achieved at a short reaction time.