Effect of β-endoxylanase and α-arabinofuranosidase enzymatic hydrolysis on nutritional and technological properties of wheat brans

Combined effects of α-amylase, xylanase, and cellulase coproduced by Stachybotrys microspora on dough properties and bread quality as a bread improver

This study aims to explore the feasibility of introducing, during the manufacture of bakery bread, an enzymatic cocktail coproduced by the fungus Stachybotrys microspora: α-amylases, xylanases and cellulases, using wheat bran as a nutrient source. Among the characteristics of the alveograph (dough tenacity "P" and dough extensibility "L"), the addition of a cocktail of enzymes at a concentration of 2 %, to weak wheat flour, has made it possible to significantly reduce its P/L ratio from 2.45 to 1.41. Furthermore, the use of enzyme cocktails at 2 %, 4 %, and 6 % concentrations increases the brown color of the bread crust. The great reduction in the rate of bread firmness, during storage over 5 days, was obtained in the presence of an enzyme cocktail in comparison with bread control (65.13 N for the control and 22.99 N, 23.24 N, and 18.24 N for bread enriched with enzyme cocktail at 2 %, 4 % and 6 % concentrations, respectively). In conclusion, the enzyme cocktail added can synergistically improve bread dough rheology and bread properties.

Enzymatic production of xylooligosaccharide from lignocellulosic and marine biomass: A review of current progress, challenges, and its applications in food sectors

Over the last decade, xylooligosaccharides (XOS) have attracted great attentions because of their unique chemical properties and excellent prebiotic effects. Among the current strategies for XOS production, enzymatic hydrolysis is preferred due to its green and safe process, simplicity in equipment, and high control of the degrees of polymerization. This paper comprehensively summarizes various lignocellulosic biomass and marine biomass employed in enzymatic production of XOS. The importance and advantages of enzyme immobilization in XOS production are also discussed. Many novel immobilization techniques for xylanase are presented. In addition, bioinformatics techniques for the mining and designing of new xylanase are also described. Moreover, XOS has exhibited great potential applications in the food industry as diverse roles, such as a sugar replacer, a fat replacer, and cryoprotectant. This review systematically summarizes the current research progress on the applications of XOS in food sectors, including beverages, bakery products, dairy products, meat products, aquatic products, food packaging film, wall materials, and others. It is anticipated that this paper will act as a reference for the further development and application of XOS in food sectors and other fields.

Arabinoxylans: A review on protocols for their recovery, functionalities and roles in food formulations

Arabinoxylans (AXs) are compounds with high nutritional value and applicability, including prebiotics or supplementary ingredients, in food manufacturing industries. Unfortunately, the recovery of AXs may require advanced separation and integrated strategies. Here, an analysis of the emerging techniques to extract AXs from cereals and their by-products is discussed. This review covers distinct methods implemented over the last 2-3 years, identifying that the type of method, extraction source, AX physicochemical properties and pre-treatment conditions are the main factors influencing the recovery yield. Alkaline extraction is among the most used methods nowadays, mostly due to its simplicity and high recovery yield. Concurrently, recovered AXs applied in food applications is timely reviewed, such as potential bread ingredient, prebiotic and as a wall material for probiotic encapsulation, in beer and non-alcoholic beverage manufacturing, complementary ingredient in bakery products and cookies, improvers in Chinese noodles, 3D food printing and designing of nanostructures for delivery platforms.

Microbial α-L-arabinofuranosidases: diversity, properties, and biotechnological applications

Arabinoxylans (AXs) are hemicellulosic polysaccharides consisting of a linear backbone of β-1,4-linked xylose residues branched by high content of α-L-arabinofuranosyl (Araf) residues along with other side-chain substituents, and are abundantly found in various agricultural crops especially cereals. The efficient bioconversion of AXs into monosaccharides, oligosaccharides and/or other chemicals depends on the synergism of main-chain enzymes and de-branching enzymes. Exo-α-L-arabinofuranosidases (ABFs) catalyze the hydrolysis of terminal non-reducing α-1,2-, α-1,3- or α-1,5- linked α-L-Araf residues from arabinose-substituted polysaccharides or oligosaccharides. ABFs are critically de-branching enzymes in bioconversion of agricultural biomass, and have received special attention due to their application potentials in biotechnological industries. In recent years, the researches on microbial ABFs have developed quickly in the aspects of the gene mining, properties of novel members, catalytic mechanisms, methodologies, and application technologies. In this review, we systematically summarize the latest advances in microbial ABFs, and discuss the future perspectives of the enzyme research.

Directed Modification of a GHF11 Thermostable Xylanase AusM for Enhancing Inhibitory Resistance towards SyXIP-I and Application of AusMPKK in Bread Making

To reduce the inhibition sensitivity of a thermoresistant xylanase AusM to xylanase inhibitor protein (XIP)-type in wheat flour, the site-directed mutagenesis was conducted based on the computer-aided redesign. First, fourteen single-site variants and one three-amino acid replacement variant in the thumb region of an AusM-encoding gene (AusM) were constructed and expressed in E. coli BL21(DE3), respectively, as predicted theoretically. At a molar ratio of 100:1 between SyXIP-I/xylanase, the majority of mutants were nearly completely inactivated by the inhibitor SyXIP-I, whereas AusMN127A retained 62.7% of its initial activity and AusMPKK retained 100% of its initial activity. The optimal temperature of the best mutant AusMPKK was 60 °C, as opposed to 60-65 °C for AusM, while it exhibited improved thermostability, retaining approximately 60% of its residual activity after heating at 80 °C for 60 min. Furthermore, AusMPKK at a dosage of 1000 U/kg was more effective than AusM at 4000 U/kg in increasing specific bread loaf volume and reducing hardness during bread production and storage. Directed evolution of AusM significantly reduces inhibition sensitivity, and the mutant enzyme AusMPKK is conducive to improving bread quality and extending its shelf life.

Individual and combined effects of α-amylase, xylanase, and cellulase on the breadmaking and nutritional properties of steamed bun enriched in wheat bran

The present study investigates the effects of α-amylase (6 and 10 ppm), xylanase (70 and 120 ppm), and cellulase (35 and 60 ppm) on the physicochemical characteristics and nutritional quality of Chinese steamed bun (CSB) incorporated with 15% wheat bran (WB). Compared to the single enzyme, the combined enzymes improved the specific volume of CSB up to the highest value (2.50 mL/g) and decreased the hardness to the minimum value (299.61 g) when the concentration was 6, 120, 35 ppm. Additionally, the combined enzymes (6, 120, and 35 ppm) significantly (p < 0.05) decreased the total dietary fiber from 14.65% to 13.10% and hence increased the area under the reducing sugar release curve during in vitro digestion from 302.12 to 357.26 mg/g. Consequently, enzymes combination can significantly improve the quality of WB CSB, whereas reduce the nutritional value of WB CSB.

Discovery of a bifunctional xylanolytic enzyme with arabinoxylan arabinofuranohydrolase-d3 and endo-xylanase activities and its application in the hydrolysis of cereal arabinoxylans

Xylanolytic enzymes, with both endo-xylanase and arabinoxylan arabinofuranohydrolase (AXH) activities, are attractive for the economically feasible conversion of recalcitrant arabinoxylan. However, their characterization and utilization of these enzymes in biotechnological applications have been limited. Here, we characterize a novel bifunctional enzyme, rAbf43A, cloned from a bacterial consortium that exhibits AXH and endo-xylanase activities. Hydrolytic pattern analyses revealed that the AXH activity belongs to AXHd3 because it attacked only the C(O)-3-linked arabinofuranosyl residues of double-substituted xylopyranosyl units of arabinoxylan and arabinoxylan-derived oligosaccharides, which are usually resistant to hydrolysis. The enzyme rAbf43A also liberated a series of xylo-oligosaccharides (XOSs) from beechwood xylan, xylohexaose and xylopentaose, indicating that rAbf43A exhibited endo-xylanase activity. Homology modelling based on AlphaFold2 and site-directed mutagenesis identified three non-catalytic residues (H161, A270 and L505) located in the substrate-binding pocket essential for its dual-functionality, while the mutation of A117 located in the -1 subsite to the proline residue only affected its endo-xylanase activity. Additionally, rAbf43A showed significant synergistic action with the bifunctional xylanase/feruloyl esterase rXyn10A/Fae1A from the same bacterial consortium on insoluble wheat arabinoxylan and de-starched wheat bran degradation. When rXyn10A/Fae1A was added to the rAbf43A pre-hydrolyzed reactions, the amount of released reducing sugars, xylose and ferulic acid increased by 9.43% and 25.16%, 189.37% and 93.54%, 31.39% and 32.30%, respectively, in comparison with the sum of hydrolysis products released by each enzyme alone. The unique characteristics of rAbf43A position it as a promising candidate not only for designing high-performance enzyme cocktails but also for investigating the structure-function relationship of GH43 multifunctional enzymes.

Influence of α-amylase, xylanase and cellulase on the rheological properties of bread dough enriched with oat bran

A better understanding of dough rheology during processing is crucial in the bakery industry, since quality attributes of the final product are influenced by those properties. In this study, we investigated the effects of xylanase, α-amylase and cellulase on the rheological properties of bread dough enriched in oat bran. A DoughLAB was used to measure the mixing characteristics of dough. According to the results, adding a single enzyme did not significantly affect the water absorption, development time, or stability of oat bran dough. In contrast, when blended enzymes were used at high concentrations (10, 120, and 60 ppm), the water absorption, development time, and stability of the oat bran dough were significantly reduced compared to using the single enzyme (62.1%, 7.1 and 6.6 min). It was found that combining α-amylase, xylanase and cellulase resulted in better extensibility and stickiness (16.5 mm and 60.8 g) of oat bran dough than using these enzymes individually. As a result, α-amylase, xylanase and cellulase complemented each other in determining the rheology of bread dough.

Effect of Enyzmes on the Quality and Predicting Glycaemic Response of Chinese Steamed Bread

The present study investigates the individual and interactional effects of α-amylase (6 and 10 ppm), xylanase (70 and 120 ppm) and cellulase (35 and 60 ppm) on the physicochemical characteristics and nutritional quality of Chinese steamed bread (CSB) incorporated with 15% oat bran. As a result, the single enzyme can significantly improve the specific volume and texture of CSB. Compared to the single enzyme, the combined enzymes improved the specific volume of CSB up to the highest value (2.51 mL/g) and decreased the hardness to the minimum value (233.61 g) when the concentration was 6, 70 and 35 ppm. With respect to chemical and nutritional properties, the addition of single enzyme had no great changes, while the combined enzymes (6, 70 and 35 ppm) significantly (p < 0.05) decreased the total starch from 37.52 to 34.11% and hence increased the area under the reducing sugar release curve during 2 h in vitro digestion (AUC) from 344.61 to 371.26. Consequently, enzymes combination can significantly improve the quality of oat bran CSB whereas reduce the nutritional value of oat bran CSB.

Integrated Technology for Cereal Bran Valorization: Perspectives for a Sustainable Industrial Approach

Current research focuses on improving the bioaccessibility of functional components bound to cereal bran cell walls. The main bioactive components in cereal bran that have major biological activities include phenolic acids, biopeptides, dietary fiber, and novel carbohydrates. Because of the bound form in which these bioactive compounds exist in the bran matrix, their bioaccessibility is limited. This paper aims to comprehensively analyze the functionality of an integrated technology comprising pretreatment techniques applied to bran substrate followed by fermentation bioprocesses to improve the bioaccessibility and bioavailability of the functional components. The integrated technology of specific physical, chemical, and biological pretreatments coupled with fermentation strategies applied to cereal bran previously-pretreated substrate provide a theoretical basis for the high-value utilization of cereal bran and the development of related functional foods and drugs.

Novel processing strategies to enhance the bioaccessibility and bioavailability of functional components in wheat bran

Dietary fiber, polysaccharides and phenols are the representative functional components in wheat bran, which have important nutritional properties and pharmacological effects. However, the most functional components in wheat bran exist in bound form with low bioaccessibility. This paper reviews these functional components, analyzes modification methods, and focuses on novel solid-state fermentation (SSF) strategies in the release of functional components. Mining efficient microbial resources from traditional fermented foods, exploring the law of material exchange between cell populations, and building a stable self-regulation co-culture system are expected to strengthen the SSF process. In addition, emerging biotechnology such as synthetic biology and genome editing are used to transform the mixed fermentation system. Furthermore, combined with the emerging physical-field pretreatment coupled with SSF strategies applied to the modification of wheat bran, which provides a theoretical basis for the high-value utilization of wheat bran and the development of related functional foods and drugs.

Optimization of Compound Ratio of Exogenous Xylanase and Debranching Enzymes Supplemented in Corn-Based Broiler Diets Using In Vitro Simulated Gastrointestinal Digestion and Response Surface Methodology

This experiment aimed to explore the zymogram of endo-xylanase (EX) and debranching enzymes (arabinofuranosidase [EA] and ferulic acid esterase [EF]) supplemented in the corn−soybean meal-based diet of broilers. An in vitro simulated gastrointestinal digestion model was adopted. According to single-factor, completely random design, the optimal supplemental levels of individual carbohydrase were determined by reducing sugars (RS) and in vitro dry matter digestibility (IVDMD). Response surface method (RSM) was used to predict the proper compound ratio of three carbohydrases. Results showed that shifts were different for feedstuffs such as corn−soybean meal−distillers dried grains with solubles, corn hull, and wheat bran, revealing that the net increase of RS or IVDMD distinctly dropped when degrading corn and related by-products by EX (p < 0.05). There was a significant quadratic relationship between the above response metrics and addition levels of each enzyme (p < 0.05). The determined dosage was 54 U/g EX, 5.0 U/g EA, and 0.4 U/g of EF, respectively. The optimistic zymogram of carbohydrases in corn basal substrates was judged by the IVDMD screening (R2 = 0.9089, p < 0.001). Conclusively, the in vitro assay and RSM were convenient and rapid methods for the optimization of xylan-degrading zymogram, and also testified asthenic hydrolysis of corn arabinoxylan by EX, thus highlighting the synergistic combinations with debranching enzymes.

Impact of Native Form Oat β-Glucan on the Physical and Starch Digestive Properties of Whole Oat Bread

To investigate the effect of oat bran on bread quality and the mechanism of reducing the glycemic index (GI) of bread, wheat bran (10%, w/w, flour basis), oat bran (10%), and β-glucan (0.858%) were individually added to determine the expansion of dough, the specific volume, texture, color, GI, starch digestion characteristics, and α-amylase inhibition rate of bread. The results showed that the incorporation of wheat bran and oat bran both reduced the final expanded volume of the dough, decreased the specific volume of the bread, and increased the bread hardness and crumb redness and greenness values as compared to the control wheat group. The above physical properties of bran-containing bread obviously deteriorated while the bread with β-glucan did not change significantly (p < 0.05). The GI in vitro of bread was in the following order: control (94.40) > wheat bran (69.24) > β-glucan (65.76) > oat bran (64.93). Correspondingly, the oat bran group had the highest content of slowly digestible starch (SDS), the β-glucan group had the highest content of resistant starch (RS), and the control group had the highest content of rapidly digestible starch (RDS). For the wheat bran, oat bran, and β-glucan group, their inhibition rates of α-amylase were 9.25%, 28.93%, and 23.7%, respectively. The β-glucan reduced the bread GI and α-amylase activity by intertwining with starch to form a more stable gel network structure, which reduced the contact area between amylase and starch. Therefore, β-glucan in oat bran might be a key component for reducing the GI of whole oat bread.

A comprehensive review of wheat phytochemicals: From farm to fork and beyond

The health benefits of whole wheat consumption can be partially attributed to wheat's phytochemicals, including phenolic acids, flavonoids, alkylresorcinols, carotenoids, phytosterols, tocopherols, and tocotrienols. It is of increasing interest to produce whole wheat products that are rich in bioactive phytochemicals. This review provides the fundamentals of the chemistry, extraction, and occurrence of wheat phytochemicals and includes critical discussion of several long-lasting issues: (1) the commonly used nomenclature on distribution of wheat phenolic acids, namely, soluble-free, soluble-conjugated, and insoluble-bound phenolic acids; (2) different extraction protocols for wheat phytochemicals; and (3) the chemistry and application of in vitro antioxidant assays. This review further discusses recent advances on the effects of genotypes, environments, field management, and processing techniques including ultrafine grinding, germination, fermentation, enzymatic treatments, thermal treatments, and food processing. These results need to be interpreted with care due to varied sample preparation protocols and limitations of in vitro assays. The bioaccessibility, bioavailability, metabolism, and potential health benefits of wheat phytochemicals are also reviewed. This comprehensive and critical review will benefit scientific researchers in the field of bioactive compounds of cereal grains and also those in the cereal food industry to produce high-quality functional foods.

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.

Wheat Bran Modifications for Enhanced Nutrition and Functionality in Selected Food Products

The established use of wheat bran (WB) as a food ingredient is related to the nutritional components locked in its dietary fibre. Concurrently, the technological impairment it poses has impeded its use in product formulations. For over two decades, several modifications have been investigated to combat this problem. Ninety-three (93) studies (review and original research) published in English between January 1997 and April 2021 reporting WB modifications for improved nutritional, structural, and functional properties and prospective utilisation in food formulations were included in this paper. The modification methods include mechanical (milling), bioprocessing (enzymatic hydrolysis and fermentation with yeasts and bacteria), and thermal (dry heat, extrusion, autoclaving), treatments. This review condenses the current knowledge on the single and combined impact of various WB pre-treatments on its antioxidant profile, fibre solubilisation, hydration properties, microstructure, chemical properties, and technological properties. The use of modified WB in gluten-free, baked, and other food products was reviewed and possible gaps for future research are proposed. The application of modified WB will have broader application prospects in food formulations.

Molecular modification, structural characterization, and biological activity of xylans

The differences in the source and structure of xylans make them have various biological activities. However, due to their inherent structural limitations, the various biological activities of xylans are far lower than those of commercial drugs. Currently, several types of molecular modification methods have been developed to address these limitations, and many derivatives with specific biological activity have been obtained. Further research on structural characteristics, structure-activity relationship and mechanism of action is of great significance for the development of xylan derivatives. Therefore, the major molecular modification methods of xylans are introduced in this paper, and the primary structure and conformation characteristics of xylans and their derivatives are summarized. In addition, the biological activity and structure-activity relationship of the modified xylans are also discussed.

Elucidation of morphological characteristics, crystallinity, and molecular structures of native and enzyme modified cereal brans

Bran is a nutritious outermost layer of the cereal grain that is removed during milling to curtail the technical problems in end-products. Modification techniques such as enzyme treatments might be an effective way to alter bran morphology and end-use quality. In this study, bran from six cereals (wheat, barley, oat, maize, millet, and sorghum) were enzymatically modified (cellulase and xylanase), and evaluated for morphological properties through scanning electron microscopy, crystallinity through x-ray diffraction and molecular structures through FTIR spectroscopy. Scanning electron microscopy revealed that enzyme modifications caused breakage in bran fibers by hydrolyzing non-starch polysaccharides. X-ray diffraction exhibited that crystallinity of the structures was increased after modifications as enzymes hydrolyzed amorphous regions of cellulose and hemicellulose in bran matrix. Molecular structures studied by FTIR spectroscopy demonstrated absorption in wavelength ranges of 900-3400cm^-1 associated to carbohydrates, oligosaccharides, proteins, and non-starch polysaccharides. PRACTICAL APPLICATIONS: Cereal bran creates technical problems for food processors and bakers in terms of grittiness leading to the unacceptability of the product. The bran can be modified using different approaches, such as enzyme modifications. This research will be helpful for the food scientists & researchers and bakers for making choices for preferred method of bran modification. This will also be helpful for cereal scientists for the understanding of structural properties of bran layers.

A review on mechanistic aspects of individual versus combined uses of enzymes as clean label-friendly dough conditioners in breads

Numerous dough improvers are used alone or in combination to enhance the quality of baked goods such as breads. While modern consumers demand consistent quality, the expectations for ingredients have changed over the past few years, and reformulations have taken place to provide "clean label" options. However, the effects and mechanisms of blended dough conditioners suitable for such baked products have not been systematically summarized. In this review, dough and bread properties as affected by different improver combinations are examined, with a focus on additive or synergistic interactions between enzymes or between enzymes and ascorbic acid. The combination of enzymes that hydrolyze starch and cell wall polysaccharides has been shown to reduce textural hardness in fresh and stored bakes goods such as breads. Enzymes that hydrolyze arabinoxylans, the main nonstarch polysaccharide in wheat, have synergistic effects with enzymes that result in cross-linking of wheat flour biopolymers. In some studies, the effects of bread improvers varied for wheat flours of different strength. Overall, bread products in which wheat is used in whole grain form or in a blend with other flours especially benefit from multiple improvers that target different flour constituents in doughs.

Debranching enzymes in corn/soybean meal-based poultry feeds: a review

This review discusses the complex nature of the primary nonstarch polysaccharide (NSP) in corn with respect to the merit of debranching enzymes. Celluloses, hemicelluloses, and pectins comprise the 3 major categories of NSP that make up nearly 90% of plant cell walls. Across cereals, the hemicellulose arabinoxylan exists as the primary NSP, followed by cellulose, glucans, and others. Differences in arabinoxylan structure among cereals and cereal fractions are facilitated by cereal type, degree and pattern of substitution along the xylan backbone, phenol content, and cross-linkages. In particular, arabinoxylan (also called glucuronoarabinoxylan) in corn is heavily fortified with substituents, being more populated than in wheat and other cereal grains. Feed-grade xylanases - almost solely of the glycoside hydrolase (GH) 10 and GH 11 families - require at least 2 or 3 contiguous xylose units to be free of attachments to effectively attack the xylan chain. This canopy of attachments, along with a high phenol content and the insoluble nature of corn glucuronoarabinoxylan, confers a significant resistance to xylanase attack. Both in vitro and in vivo studies demonstrate that debranching enzymes appreciably increase xylanase access and fiber degradability by removing these attachments and breaking phenolic linkages. The enzymatic degradation of the highly branched arabinoxylan can facilitate disassembly of other fibers by increasing exposure to pertinent carbohydrases. For cereals, the arabinofuranosidases, α-glucuronidases, and esterases are some of the more germane debranching enzymes. Enzyme composites beyond the simple core mixes of xylanases, cellulases, and glucanases can exploit synergistic benefits generated by this class of enzymes. A broad scope of enzymatic activity in customized mixes can more effectively target the resilient NSP construct of cereal grains in commercial poultry diets, particularly those in corn-based feeds.

Characterization of recombinant rice quiescin sulfhydryl oxidase and its improvement effect on wheat flour-processing quality

In this study, recombinant rice quiescin sulfhydryl oxidase (rQSOX) was expressed and characterized, and its performance in flour-processing quality was further evaluated. The purified rQSOX exhibited the highest sulfhydryl oxidation activity (1.96 IU/mg) using dithiothreitol as a substrate, accompanying the production of H₂O₂. The optimal temperature and pH were 60 °C and pH 8.0 for rQSOX catalyzing oxidation of dithiothreitol. And rQSOX retained 50% of its maximum activity after incubation at 80 °C for 1 h. Moreover, rQSOX supplementation improved the farinograph properties of dough, indicated by the increased dough stability time and decreased degree of softening, and enhanced viscoelastic properties of the dough. Addition of rQSOX (10 IU/g flour) provided remarkable improvement in specific volume (37%) and springiness (17%) of the steamed bread, and significantly reduced the hardness by half, which was attributed to the strengthened gluten network. The results provide an understanding for rQSOX using in flour-processing industry.

Bioactive Components and Health Beneficial Properties of Whole Wheat Foods

Epidemiological studies have found that whole wheat consumption is inversely associated with the risk of chronic diseases, such as obesity, type 2 diabetes, cardiovascular diseases, and cancer. The health benefits of whole wheat foods are attributed to their bioactive components, including phytochemicals and dietary fiber. In this review, the current studies regarding bioactive components and their health-promoting roles and the underlying mechanisms were summarized and discussed. The current research advances in processing technologies capable of potentially enhancing the nutritional quality of wheat and wheat-based foods were also included. This review may promote the research, development, and consumption of whole wheat foods in reducing the risk of human chronic diseases.

Enzyme Selection and Hydrolysis under Optimal Conditions Improved Phenolic Acid Solubility, and Antioxidant and Anti-Inflammatory Activities of Wheat Bran

Valorization of wheat bran (WB) into new high-value products is of great interest within the framework of sustainability and circular economy. In the present study, we utilized a multi-step approach to extract nutraceutical compounds (phenolic acids) from WB and improved its antioxidant and anti-inflammatory properties through using sequential hydrothermal and enzymatic hydrolysis. Thirteen commercial glycosidases differing in their specific activity were screened and compared for hydrolytic efficiency to release monosaccharides, ferulic acid, and diferulic acid. Ultraflo XL was selected as the desired enzyme treatment on the basis of its higher WB solubilization, as well as its monosaccharide and phenolic acids yields. The relationships between better hydrolytic performance of Ultraflo XL and its particular activity profile were established. To determine the optimum conditions for Ultraflo XL treatment, we tested different factors (solvent pH, incubation temperature, and time) under 15 experiments. A multicomponent analysis (MCA), including central composite design, model fitness, regression coefficients, analysis of variance, 3D response curves, and desirability, was used for processing optimization. A beneficial effect of autoclave treatment on the release of phenolic compounds was also evidenced. The results of MCA showed involvement of linear, quadratic, and interactive effects of processing factors, although solvent pH was the main determinant factor, affecting enzymatic extraction of phenolics and bioactivity of hydrolysates. As compared to control WB, under optimized conditions (47 °C, pH = 4.4, and 20.8 h), WB hydrolysates showed 4.2, 1.5, 2, and 3 times higher content of ferulic acid (FA) and capacity to scavenge oxygen radicals, chelate transition metals, and inhibit monocyte chemoattractant protein-1 secretion in macrophages, respectively. These approaches could be applied for the sustainable utilization of WB, harnessing its nutraceutical potential.