Fine structural features and antioxidant capacity of ferulated arabinoxylans extracted from nixtamalized maize bran

Abstract

BACKGROUND The nixtamalization process improves the nutritional and technological properties of maize. This process generates nixtamalized maize bran as a by‐product, which is a source of arabinoxylans (AX). AX are polysaccharides constituted of a xylose backbone with mono‐ or di‐arabinose substitutions, which can be ester‐linked to ferulic acid (FA). The present study investigated the fine structural features and antioxidant capacity (AC) of nixtamalized maize bran arabinoxylans (MBAX) to comprehend the structure–radical scavenging capacity relationship in this polysaccharide deeply. RESULTS MBAX presented a molecular weight, intrinsic viscosity, and hydrodynamic radius of 674 kDa, 1.8 dL g−1, and 24.6 nm, respectively. The arabinose‐to‐xylose ratio (A/X) and FA content were 0.74 and 0.25 g kg−1 polysaccharide, respectively. MBAX contained dimers (di‐FA) and trimer (tri‐FA) of FA (0.14 and 0.07 g kg−1 polysaccharide, respectively). The main di‐FA isomer was the 8–5′ structure (80%). Fourier transform infrared spectroscopy confirmed MBAX molecular identity, and the second derivate of the spectral data revealed a band at 958 cm−1 related to the presence of arabinose disubstitution. 1H‐Nuclear magnetic resonance spectroscopy showed mono‐ and di‐arabinose substitution in the xylan backbone with more monosubstituted residues. MBAX registered an AC of 25 and 20 μmol Trolox equivalents g−1 polysaccharide despite a low FA content, using ABTS (2,2′‐azino‐bis‐3‐ethylbenzthiazoline‐6‐sulfonic acid) and DPPH (1,1‐diphenyl‐2‐picrylhydrazyl) methods, respectively. CONCLUSION AC in MBAX could be related to the high A/X ratio (mainly monosubstitution) and the high 8–5′ di‐FA proportion in this polysaccharide. © 2023 Society of Chemical Industry.

Antifreeze Polysaccharides from Wheat Bran: The Structural Characterization and Antifreeze Mechanism

“…The polydispersity index (PDI), defined as M w / M n , was 2.06 and 2.68 for GDIF50W and 60N, respectively. The results generally in accordance with the previous studies suggest that the PDI of cereal AX ranges from 1.0 to 3.0 . A polymer characterized by a homogeneous M w distribution typically has a polydispersity value close to 1, indicating a relatively heterogeneous nature of the polysaccharides.…”

“…The results generally in accordance with the previous studies suggest that the PDI of cereal AX ranges from 1.0 to 3.0. 38 A polymer characterized by a homogeneous M w distribution typically has a polydispersity value close to 1, indicating a relatively heterogeneous nature of the polysaccharides. A conformation plot slope below 0.33 indicates a tight, uniform spherical conformation, whereas a range of 0.5 to 0.6 denotes a random coil conformation.…”

Extraction, Identification, and In Vitro Anti-Inflammatory Activity of Feruloylated Oligosaccharides from Baijiu Distillers’ Grains

“…Enzymatic hydrolysis, utilizing xylanase, cellulase, or breakdown enzymes, presents milder reaction conditions that preserve the structure of POs. Notably, POs has been discovered and utilized in the redevelopment of agricultural by-products such as corn bran, wheat bran, and brewers spent grain, contributing to the sustainable utilization of agricultural residues [9][10][11].…”