Effect of chemical, thermal, and enzymatic processing of wheat bran on the solubilization, technological and biological properties of non-starch polysaccharides

Abstract

Wheat bran is a low-cost by-product with significant nutritional value, but it is primarily utilized in animal feed applications. This study sought to investigate chemical methodologies for modifying the wheat bran´s structure, enhancing non-starch polysaccharides solubility in water, and assessing alterations in functional and biological attributes. Chemical modifications were conducted under aqueous, alkaline, acid, and oxidizing conditions. Parameters such as yield, monosaccharides, arabinoxylans, β-glucan and phenolic content, molecular weight, functional properties, and prebiotic in vitro capacity were examined. The samples exhibited higher yields than the control, particularly in alkaline and acidic extractions. Notably, all soluble polysaccharide fractions (SPF) displayed a reduced molecular weight (<25KDa). β-glucan contents were raised in alkaline and acid extractions compared to the control, despite only in alkaline extraction were observed increase in arabinoxylans, confirmed by enzymatic-driven linkage analyses. Phenolic compounds and their antioxidant activities were low across all SPF. The samples showed heightened solubility, minimal foaming, and reduced water absorption properties. An alkaline extraction demonstrated a potential high prebiotic effect. Most samples showed positive relative growth and prebiotic activity for Lactobacillus and Bifidobacterium. This study suggests that an alkaline extraction of wheat by-product could enhance its value by increasing β-glucan content, arabinoxylans release, and prebiotic potential.