Structural and emulsion-stabilizing properties of the alkali-extracted arabinoxylans from corn and wheat brans

Structural and quantitative changes in alkali-solubilized arabinoxylan throughout the breadmaking process

Arabinoxylan (AX) substantially impacts wheat dough and bread quality; however, the behavior of water-unextractable AX (WU-AX) during breadmaking is not fully understood. This study investigates WU-AX changes during breadmaking by treating it with various sodium hydroxide (NaOH) concentrations to produce alkali-solubilized AX (AS-AX). Higher NaOH concentrations (up to 2.0 M) increase the AS-AX ratio, reaching over 80 %. The release of ferulic acid also increases with NaOH concentration but plateaus at 0.5 M NaOH. Analysis with 50 mM NaOH revealed the AS-AX ratio decreased from 46.0 % in wheat flour to 30.5 % at the proof stage, indicating WU-AX conversion to water-extractable AX (WE-AX) through the cleavage of ferulic acid-mediated bonds. High and low molecular weight AS-AX exhibit different solubilization patterns; low molecular weight AX with weaker bonds solubilizes more readily and converts preferentially to WE-AX. Understanding these dynamic changes can enhance dough properties and bread quality through targeted WU-AX.

Effect of induced electric field treatment on structural and physicochemical properties of wheat bran to enhance soluble dietary fiber content

Improving the content and physicochemical properties of soluble dietary fiber (SDF) in wheat bran (WB) is conducive to enhancing the palatability and processing adaptability of bran-containing products. In this study, induced electric field (IEF) was employed for the modification of WB. The IEF modification conditions were optimized, and the effects on the structural and physicochemical properties of WB and its SDF were evaluated. The results showed that under the excitation voltage of 500 V, treatment time of 40 min, and NaCl concentration of 0.1 %, the SDF content in WB increased from 7.69 % to 12.02 %. The IEF-modified WB exhibited a porous structure and better hydration capabilities. Furthermore, the IEF modification resulted in a reduction in the crystallinity of WB, from 10.07 % to 9.06 %, and in the thermal stability, from 300.02℃ to 287.58℃ of the maximum decomposition. The SDF extracts study showed that IEF treatment destroyed the compact structure, reduced the thermal stability, and decreased the molecular weight and particle size from 1010 nm to 227 nm. In conclusion, IEF can effectively increase the SDF content and improve the quality of WB, which offers a theoretical reference for the comprehensive utilization of WB.

Enhancing Mechanical Properties of Corn Bran Arabinoxylan Films for Sustainable Food Packaging

Arabinoxylan (AX)-based films can improve the mechanical characteristics of biodegradable materials when utilized for food packaging. However, the mechanical properties of AX films for food packaging applications require thorough investigation to establish their viability. In this study, AX was extracted from corn bran coproducts of dry-milling (DCB), wet-milling (WCB), and dried distiller's grains with solubles (DDGS) using an acid-alkali method. Packaging materials were produced using these AX extracts, each combined with laccase and sorbitol, forming the basis for three different films. These films were then modified by immersing the surface in a lipase-acetate solution. We evaluated their mechanical characteristics, including thickness, tensile properties, tear resistance, and puncture resistance. The thickness and tensile properties of the modified AX films derived from DCB and DDGS showed significant improvements (p < 0.05) compared to the unmodified AX films. In contrast, the modified AX films from WCB showed no significant changes (p > 0.05) in thickness and tensile properties compared to the unmodified WCB AX films. A significant increase in tear resistance (p < 0.05) was observed in all modified AX films after immersion in the lipase-acetate mixture. While puncture resistance was enhanced in the modified AX films, the improvement was not statistically significant (p > 0.05) compared to the unmodified films. The presence of hydroxyl (OH) and carbonyl (CO) groups on the surfaces of AX films from DCB and DDGS, modified by the lipase-acetate solution, suggests excellent biodegradability properties. The modification process positively affected the AX films, rendering them more bendable, flexible, and resistant to deformation when stretched, compared to the unmodified AX films.

A multi-scale approach to arabinoxylan-based emulsions: From molecular features, interfacial properties to emulsion behaviors

Arabinoxylan (AX) is well-known for its emulsification and beneficial biological activity, but the roles of AX's molecular features and interfacial properties in AX-based emulsion behaviors were unknown. We first used a multi-scale approach to correlate molecular, interfacial, droplet characteristics, and bulk emulsion of AXs from corn and wheat bran (CAXs and WAXs). Our results showed that among CAXs and WAXs solution (1 %, 2 % and 3 %, w/v), 0.25 M NaOH-treated CAX and WAX showed smaller particle sizes (493 nm and 8621 nm), lower interfacial tension and stronger interfacial layer, whose emulsion exhibited smaller initial droplets (541 nm and 660 nm) and better stability. Moreover, WAXs had bigger particle sizes, lower interfacial tension and stronger interfacial layer than CAXs, but CAXs exhibited better emulsifying and emulsion-stabilizing properties than WAXs. There is a satisfactory correlation among CAXs' or WAXs' molecular features, interfacial properties and emulsion behaviors. However, a good correlation from different grains AXs cannot be established.