Abstract: Arabinoxylans (AXs) were extracted from fresh maize barn with four xylanases commonly used in the food industry, Grindmyl Powerbake 950, Pentopan mono BG, Viscozyme L and Amano HC 90. The monosaccharide composition and molecular mass distribution of the extracts were analyzed by gas chromatography (GC) and high-performance sizeexclusion chromatography (HPSEC). The optimum xylanase was selected and its optimum dosage was determined. Monosaccharide composition analysis showed that the four AXs were mainly composed of arabinose and xylose. The purity of the AX extracted with Amano HC 90 for 24 h was 70.51%, and the extraction yield was (17.37 ± 2.74)%. The weight average molecular mass of the AX was (67.87 ± 1.46) × 104 g/mol, the number average molecular mass was (15.06 ± 0.09) × 104 g/mol, and the relative molecular mass dispensability was 4.51 ± 0.13. Amano HC 90 gave a higher purity and yield of AX with higher molecular mass and more homogenous molecular mass distribution. Thus, this xylanase was more suitable for the extraction of AX from maize bran in the food industry, and its optimum dosage was 1 500 U/g.

Key words: maize bran, hydrolysis, monosaccharide composition, molecular mass distribution