Partial removal of protein associated with arabinoxylans: Impact on the viscoelasticity, crosslinking content, and microstructure of the gels formed

Abstract

Arabinoxylans (AX) treated with protease and dialyzed (AXP) or only dialyzed (AXD) formed gels showing an increase in the elastic modulus G 0 (1291 and 1419 Pa, respectively) and the ferulic acid dimers (3.34 and 3.10 μg/mg polysaccharide, respectively) and trimers (0.51 and 0.53 μg/mg polysaccharide, respectively) in comparison to AX gels (767 Pa, 0.56 and 0.12 μg/mg polysaccharide, respectively). Nevertheless, the G 0 values and crosslinking contents were not different among the AXP and AXD gels, suggesting that the amount of protein removed (54%) does not affect these parameters. Confocal laser scanning microscopy analysis showed that AXP treatment promotes the homogeneity of the gels. In addition, scanning electron microscopy observations indicated that AXD and particularly AXP gels had a more compact microstructure. Thus, the partial removal of protein associated with AX does not impact the viscoelasticity and crosslinking content of the gels formed but could improve their microstructural characteristics.

Feruloylated Arabinoxylans from Maize Distiller’s Dried Grains with Solubles: Effect of Feruloyl Esterase on their Macromolecular Characteristics, Gelling, and Antioxidant Properties

“…Small levels of glucose, galactose, and mannose were also quantified. The FA content (3.27 µg/mg AXs) was lower than the value previously reported using 30 min of alkaline hydrolysis (7.53 µg/mg AXs) [3], which could be attributed to an extensive chemical de-esterification of FA during 1 h of alkaline hydrolysis used in the present work. However, the FA content reported in AXs extracted from DDGS is higher than that reported for AXs isolated from other maize co-products, such as maize wastewater generated during nixtamalization (0.012-0.23 µg/mg AXs) [26].…”

“…AXs were extracted from 500 g of DDGS to yield 4.7% (w AXs/w DDGS) on a dry matter basis, which is higher than the value previously reported using 30 min of alkaline hydrolysis (2.5% w AXs/w DDGS) [3]. Extracted AXs consisted of white-colored powder with fine and granulated parts (Figure 3).…”

“…AXs were extracted as previously reported [3]. In brief, DDGS (500 g) was treated with 2500 mL of absolute ethanol to remove the lipophilic components (100 rpm, 25 • C, 12 h).…”

“…The FT-IR spectrums of AXs and FAXs powder were recorded on a Nicolet iS50 FT-IR spectrophotometer (Nicolet Instrument Corp., Madison, WI, USA). The AXs and FAXs were placed on a smart iTX module, and the spectrums were recorded in the range of 4000-500 cm −1 with 4 cm −1 resolution and 32 scans [3]. OMNIC 9.3.32 software was used for data processing.…”

“…One of the significant co-products of the maize-based bioethanol generation is the distiller's dried grains with solubles (DDGS) fraction, which is usually utilized as a feed ingredient in animal production. DDGS have been previously investigated as a potential source of arabinoxylans (AXs) [2,3]. AXs are formed by a linear chain of β-1, 4 xyloses, which may or may not be substituted by α-1,3 and α-1,2 arabinose units.…”