Optimization of Extraction Method of Arabinoxylan from Maize Bran and Analysis of Its Gel Properties

In order to further explore the added value of corn bran and improve the processing and application of AX, this study used the corn bran as raw material, optimized its extraction process by alkaline preparation, and explored its gel characteristics. AX was extracted from bran, a by-product of deep processing of corn, by using Ba(OH)2. A response surface optimization with three factors and three levels was constructed based on the ratio of material to liquid, extraction temperature and extraction time. The structure of the optimized polysaccharide was characterized by monosaccharide composition, molecular weight and ferulic acid content. On this basis, AX was oxidized and cross-linked by laccase to explore the formation conditions, gel structure and thermal stability of AX gel. The results showed that the optimized extraction conditions of AX were as follows: Solid-liquid ratio 1:44 (g:mL), extraction temperature 69 ℃, extraction time 6.3 h, and the yield of AX was 23.07%±1.15%. The obtained AX was mainly composed of arabinose and xylose. The Ara/Xyl ratio was 2.28±0.11, the weight average molecular weight was 265±6.68 kDa, and the ferulic acid content was 9.6±0.32 mg/100 g. AX could form a stable gel structure under the condition of pH2.0 after laccase oxidation and cross-linking. The microstructure of AX was a dense porous gel structure and had good thermal stability according to scanning electron microscope. Arabinoxylan and its gel prepared in this study had good physical and chemical properties, and had potential application in improving the texture quality of food, embedding and controlled release of functional factors. This paper provides a theoretical basis for the further processing of corn by-products and the application of arabinoxylan in food industry.