Optimisation of double-enzymatic extraction of arabinoxylan from fresh corn fibre

Cereal-Derived Water-Unextractable Arabinoxylans: Structure Feature, Effects on Baking Products and Human Health

Arabinoxylans (AXs) are non-starch polysaccharides with complex structures naturally occurring in grains (i.e., barley, corn, and others), providing many health benefits, especially as prebiotics. AXs can be classified as water-extractable (WEAX) and water-unextractable (WUAX) based on their solubility, with properties influenced by grain sources and extraction methods. Numerous studies show that AXs exert an important health impact, including glucose and lipid metabolism regulation and immune system enhancement, which is induced by the interactions between AXs and the gut microbiota. Recent research underscores the dependence of AX physiological effects on structure, advocating for a deeper understanding of structure-activity relationships. While systematic studies on WEAX are prevalent, knowledge gaps persist regarding WUAX, despite its higher grain abundance. Thus, this review reports recent data on WUAX structural properties (chemical structure, branching, and MW) in cereals under different treatments. It discusses WUAX applications in baking and the benefits deriving from gut fermentation.

Improving Biodegradable Films from Corn Bran Arabinoxylan for Hydrophobic Material and Green Food Packaging

Non-biodegradable plastic materials pose environmental hazards and contribute to pollution. Arabinoxylan (AX) films have been created for applications in food packaging to replace these materials. The water interaction characteristics of biodegradable AX films were assessed following the extraction of AX from dry-milled corn bran (DCB), wet-milled corn bran (WCB), and dried distiller's grains with solubles (DDGS). Films were prepared with laccase and sorbitol before surface modification with lipase-vinyl acetate. Water solubility of the modified DCB films was significantly reduced (p < 0.05); however, the water solubility of modified WCB films decreased insignificantly (p > 0.05) compared to unmodified films. Water vapor permeability of the modified AX films from WCB and DDGS was significantly reduced (p < 0.05), unlike their unmodified counterparts. The biodegradation rates of the modified WCB AX and DDGS films increased after 63 and 99 days, respectively, compared to the unmodified films. The hydrophilic nature of AX polymers from WCB and DDGS enhances the biodegradability of the films. This study found that the modified WCB AX film was more hydrophobic, and the modified DDGS AX film was more biodegradable than the modified DCB AX film. Overall, surface modifications have potential for improving hydrophobicity of biopolymer films.

Ascorbic acid-mediated reduction of arabinoxylan viscosity through free radical reactions

Arabinoxylan (AX) is a potential natural food additive that can enhance the textural properties of food. However, the addition of ascorbic acid (AA) can easily lead to a decrease in the viscosity of AX, which poses a challenge in the development of AX-rich foods. Therefore, the purpose of this study is to elucidate the mechanisms behind the reduction in AX viscosity in the presence of AA. The results indicated that AA could reduce the apparent viscosity and molecular weight of AX without significantly affecting the monosaccharide composition, suggesting a potential mechanism related to the cleavage of AX glycosidic bonds. Interestingly, free radicals were present in the reaction system, and the generation of free radicals under different conditions was consistent with the reduction in apparent viscosity of AX. Furthermore, the reduction in AX apparent viscosity by AA was influenced by various factors including AA concentration, reaction time, temperature, pH, and metal ions. These findings suggested that the mechanism of AX degradation may be due to AA-induced free radical generation, leading to non-selective attacks on glycosidic bonds. Therefore, this study revealed that the potential mechanism behind the reduction in AX viscosity induced by AA involved the generation of ascorbic acid radicals.

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.

Effects of Co-Modification by Extrusion and Enzymatic Hydrolysis on Physicochemical Properties of Black Wheat Bran and Its Prebiotic Potential

Black wheat bran (BWB) is an important source of dietary fiber (DF) and phenolic compounds and has stronger nutritional advantages than ordinary WB. However, the low content of soluble dietary fiber (SDF) negatively influences its physicochemical properties and nutritive functions. To obtain a higher content of SDF in BWB, we evaluated the impact of co-modification by extrusion and enzymes (cellulase, xylanase, high-temperature α-amylase, and acid protease) on water extractable arabinoxylan (WEAX) in BWB. An optimized co-modification method was obtained through single-factor and orthogonal experiments. The prebiotic potential of co-modified BWB was also evaluated using pooled fecal microbiota from young, healthy volunteers. The commonly investigated inulin served as a positive control. After co-modification, WEAX content was dramatically increased from 0.31 g/100 g to 3.03 g/100 g (p < 0.05). The water holding capacity, oil holding capacity, and cholesterol adsorption capacity (pH = 2.0 and pH = 7.0) of BWB were increased by 100%, 71%, 131%, and 133%, respectively (p < 0.05). Scanning electron microscopy demonstrated a looser and more porous microstructure for co-modified BWB granules. Through in vitro anerobic fermentation, co-modified BWB achieved a higher content of Bifidobacterium and Lactobacillus than inulin fermentation. In addition, co-modified BWB induced the highest butyric acid production, indicating high potential as prebiotics. The results may contribute to improving technologies for developing high-fiber-content cereal products.

Ultrasound-assisted extraction and characteristics of maize polysaccharides from different sites

Antitumor, antioxidant, hypoglycemic, and immunomodulatory properties are all exhibited by maize polysaccharides. With the increasing sophistication of maize polysaccharide extraction methods, enzymatic method is no longer limited to a single enzyme to extract polysaccharides, and is more often used in combination with ultrasound or microwave, or combination with different enzymes. Ultrasound has a good cell wall-breaking effect, making it easier to dislodge lignin and hemicellulose from the cellulose surface of the maize husk. The "water extraction and alcohol precipitation" method is the simplest but most resource- and time-consuming process. However, the "ultrasound-assisted extraction" and "microwave-assisted extraction" methods not only compensate for the shortcoming, but also increase the extraction rate. Herein, the preparation, structural analysis, and activities of maize polysaccharides were analyzed and discussed.

Arabinoxylans as Functional Food Ingredients: A Review

The health benefits of fibre consumption are sound, but a more compressive understanding of the individual effects of different fibres is still needed. Arabinoxylan is a complex fibre that provides a wide range of health benefits strongly regulated by its chemical structure. Arabinoxylans can be found in various grains, such as wheat, barley, or corn. This review addresses the influence of the source of origin and extraction process on arabinoxylan structure. The health benefits related to short-chain fatty acid production, microbiota regulation, antioxidant capacity, and blood glucose response control are discussed and correlated to the arabinoxylan's structure. However, most studies do not investigate the effect of AX as a pure ingredient on food systems, but as fibres containing AXs (such as bran). Therefore, AX's benefit for human health deserves further investigation. The relationship between arabinoxylan structure and its physicochemical influence on cereal products (pasta, cookies, cakes, bread, and beer) is also discussed. A strong correlation between arabinoxylan's structural properties (degree of branching, solubility, and molecular mass) and its functionalities in food systems can be observed. There is a need for further studies that address the health implications behind the consumption of arabinoxylan-rich products. Indeed, the food matrix may influence the effects of arabinoxylans in the gastrointestinal tract and determine which specific arabinoxylans can be included in cereal and non-cereal-based food products without being detrimental for product quality.

Valorization of cereal by-product hemicelluloses: Fractionation and purity considerations

The biomass from cereal side streams is rich in valuable components, such as hemicelluloses. Among the hemicelluloses, arabinoxylans and β-glucans are the most acknowledged for potential health benefits. Numerous publications discuss the potential to use purified forms of these hemicelluloses for various applications. However, as the purification of hemicelluloses may not be economically feasible to upscale, sustainable and cost-effective methods are needed to make their valorization more realistic for industrial applications. Co-components present in hemicellulose-rich fractions may also provide added functionality, such as flavonoid content and antioxidant capacity. This review provides an overview on the feasibility of sustainably upscaling hemicellulose extraction processes, focusing on by-products from different cereal streams. We describe the hemicelluloses' physicochemical properties and provide various possible applications of pure and impure fractions from small scale to pilot and industrial scale. Furthermore, real case examples on the industrial utilization of cereal side streams are enclosed. This review provides pathways for future research for developing the hemicellulose extraction methods to obtain fractions with optimized purity, and offers suggestions to valorize them.

Preparation and Evaluation of Self-emulsifying Drug Delivery System (SEDDS) of Cepharanthine

The aim of this article was to design a self-emulsifying drug delivery system (SEDDS) of loaded cepharanthine (CEP) to improve the oral bioavailability in rats. Based on the solubility determination and pseudo-ternary phase diagram, isopropyl palmitate (IPP) was chosen as the oil phase. Meanwhile, Cremophor RH40 and Macrogol 200 (PEG 200) were chosen as the emulsifier and co-emulsifier, respectively. This prescription was further optimized by using central composite design of response surface methodology. The optimized condition was CEP:IPP:Cremophor RH40:PEG 200=3.6:30.0:55.3:11.1 in mass ratio with maximum drug loading (36.21 mg/mL) and the minimum particle size (36.70 nm). The constructed CEP-SEDDS was characterized by dynamic light scattering, transmission electron microscopy, in vitro release and stability studies. The dissolution level of CEP-SEDDS was nearly 100% after 30 min in phosphate-buffered saline (PBS, pH 6.8) which was higher than that of the pure CEP (approximately 20%). In addition, in vivo pharmacokinetic study in rats showed that CEP-SEDDS dramatically improved bioavailability compared with active pharmaceutical ingredient (API) (the relative bioavailability was 203.46%). In this study, CEP-SEDDS was successfully prepared to enhance the oral bioavailability which might facilitate to increase its better clinical application.