Ferulated arabinoxylans as by-product from maize wet-milling process: Characterization and gelling capability

Maize bran is a by-product of the commercial maize wet-milling process in Mexico. This process involves nixtamalization, which is an alkali cooking widely used to improve the maize nutritional value. Maize nixtamalization is important in Mexico as half of the total volume of consumed food is maize. This process degrades and solubilizes maize cell wall components allowing bran removal. Due the high volume of maize bran generated in Mexico, it is becoming into a potential source of added-value biomolecules such as ferulated arabinoxylans. This chapter has been focused on the extraction, characterization and gelling capability evaluation of maize bran ferulated arabinoxylans recovered from maize nixtamalization (N-FAX). Yield of ferulated arabinoxylans extracted from maize bran was 18% (w/w) on a dry matter basis (w N-FAX/w maize bran). N-FAX presented a pure arabinoxylan content of 85 % (w/w), a ferulic acid content of 0.25 μg/mg arabinoxylans, an A/X ratio of 0.75, an intrinsic viscosity [η] of 268 mL/g and a viscosimetric molecular weight (Mv) of 197 kDa. Gelling capability of ferulated arabin-oxylans at different concentrations was investigated. Gels were obtained from this polysaccharide by laccase covalent cross-linking of ferulic acid. Large deformation mechanical tests (compression mode) revealed an increase in strength from 45 to 60 N as N-FAX concentration changed from 2 to 4 % (w/v). Lightness (L), redness (a), and yellowness (b) values were registered for N-FAX gels at both concentrations. Significant differences were found for b values, which increased as the polysaccharide concentration augmented from 2 to 4% (w/v) in the gel. Extraction of N-FAX from maize wet-milling process could represent an alternative source of this polysaccharide which is receiving increasing attention for food and non-food applications. © 2012 Nova Science Publishers, Inc. All rights reserved.