Extrusion Modification of Wheat Bran and Its Effects on Structural and Rheological Properties of Wheat Flour Dough

Modifications and functional applications of cereal non-starch polysaccharides: Structure-property relationships and industrial potentials in food systems

This review provides recent advancements in modification of cereal cell wall non-starch polysaccharides (NSPs) and their functional applications in food systems. NSPs, predominantly derived from cereal bran, play a critical role in food texture, functionality, and health-promoting properties. However, their natural characteristics often limit their direct application in foods. This article systematically examines various modification strategies, including chemical, physical, and enzymatic approaches, aimed at enhancing the solubility, viscosity, gelation, and emulsification properties of NSPs. Such modifications improve their performance as thickeners, stabilizers, and emulsifiers, while simultaneously boosting their biological activities, such as hypoglycemic, cholesterol-lowering, and antioxidant effects. The review also explores the molecular mechanisms behind these modifications and their interactions with other food components, to optimize food structure and stability. By summarizing recent innovations and outlining challenges and future research directions, this work offers valuable insights for advancing the use of modified cereal NSPs in food science.

Transforming oilseed blends: the impact of low-moisture extrusion on antinutritional factors, protein structure, and nutritional value

Oilseed cakes from hemp, rapeseed, and flaxseed are protein-rich, sustainable sources but are limited in food applications by antinutritional factors. This study blended meals from these oilseeds with pea or hemp protein ingredients (50:50 w/w) and applied low moisture extrusion (10 % and 20 %) at 122 °C to investigate their impact on physicochemical characteristics of oilseeds blends. Extrusion preserved protein content, reduced protein solubility by up to 44.5 %, and improved in vitro digestibility by up to 13.5 %. Antinutritional factors, including polyphenols (-10.18 % to -52.80 %), saponins (-4.48 % to -21.31 %), condensed tannins (-20.37 % to -41.05 %), and trypsin inhibitors (-2.26 TIU/mg to -13.31 TIU/mg), were significantly reduced, though phytic acid content was less affected. Extrusion decreased surface hydrophobicity, disrupted protein-protein interactions, altered secondary structures, and retained protein profiles under reducing conditions. These findings provided valuable scientific insights into the application of extrusion in enhancing nutritional value and modifying structure of plant-based meat alternatives.

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.

Effect of the Extruded Pea Hulls on Physicochemical and Sensory Properties of Wheat Bread

Incorporating extruded pea hulls (EPH) into wheat bread increases its nutritional value by increasing dietary fiber content, which in turn influences the physicochemical properties and sensory attributes of bread. This study aimed to assess the effect of varying EPH levels on the rheological properties of wheat dough, as well as on the physical and sensory attributes of wheat bread, providing insight into the optimal EPH inclusion level. Farinograph analysis indicated that the inclusion of extruded pea hulls progressively increased the water absorption capacity. At higher EPH replacement levels, bread exhibited decreased specific volume, increased hardness, reduced porosity, darker color, and pronounced sensory attributes of pea aroma and pea taste. Bread with 5-15% EPH retained physical qualities comparable to bread without EPH, with 5% EPH replacement particularly improving specific volume, porosity, and texture. However, 20-30% EPH significantly impaired bread quality, resulting in denser crumb, darker crumb color, and intensified pea aroma. These findings suggest that moderate EPH inclusion (up to 15%) is optimal for enhancing fiber content without compromising bread quality, while higher levels (20% and more) may negatively affect both physical and sensory attributes.

Insight into konjac glucomannan-retarding deterioration of steamed bread during frozen storage: Quality characteristics, water status, multi-scale structure, and flavor compounds

Konjac glucomannan (KGM), a water-soluble hydrocolloid, holds considerable potential in the food industry, especially for improving the quality and nutritional properties of frozen products. This study explored the alleviative effect of KGM on the quality characteristics, water status, multi-scale structure, and flavor compounds of steamed bread throughout frozen storage. KGM significantly improved the quality of steamed bread by slowing down the decrease in water content and the increase in water migration while maintaining softness and taste during frozen storage. Notably, KGM also delayed amylopectin retrogradation and starch recrystallization, thus preserving the texture and structure of the steamed bread. At week 3, the microstructure of the steamed bread with 1.0 % KGM remained intact, with the lowest free sulfhydryl content. Additionally, heat map analysis revealed that KGM contributed to flavor retention in steamed bread frozen for 3 weeks. These results indicate that KGM holds promise as an effective cryoprotectant for improving the quality of frozen steamed bread.

Study on the prebiotic effects of insoluble crude and fine fibers of wheat bran after simulated digestion in vitro

This study aims to evaluate the probiotic effects of insoluble crude and fine fibers of wheat bran on the intestine after simulated in vitro digestion. It was found that the particle size distribution of modified fine wheat bran (MWB) was significantly smaller than that of natural crude wheat bran (NWB). MWB had a looser texture and more porous structure. The dry matter digestibility and organic matter digestibility of MWB were 58.60 % and 59.05 %, which were significantly higher than that of NWB (53.64 % and 54.13 %). More SDF and free polyphenol were released from the MWB. At 12 h of fermentation, the SDF content of the MWB was 3.76 g/100 g, significantly higher than NWB (3.40 g/100 g), and the free polyphenol was 9.43 mg/g, significantly higher than NWB (9.01 mg/g). The content of short-chain fatty acids including formic acid, acetic acid, propionic acid, butyrate acid and valerate acid in the samples were significantly higher in MWB than in NWB. Analysis of the microbial flora structure and diversity of the fermentation samples revealed that the relative abundance of Lactobacillus was higher in the MWB group, and was closer to the oligofructose group (FOS) in terms of functional predictions.

Effect of Solid-State Fermentation of Hericium erinaceus on the Structure and Physicochemical Properties of Soluble Dietary Fiber from Corn Husk

Corn husk, a by-product of corn starch production and processing, contains high-quality dietary fiber (DF). Our study compares and analyzes the impact of Hericium erinaceus solid-state fermentation (SSF) on the structure and physicochemical characteristics of soluble dietary fiber (SDF) of corn husks. The study also investigates the kinetics of SSF of H. erinaceus in this process. The scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR) results revealed significant structural changes in corn husk SDF before and after fermentation, with a significant elevation in the functional group numbers. The data indicate that the fermented corn husk SDF's water-holding, swelling, and oil-holding capacities increased to 1.57, 1.95, and 1.80 times those of the pre-fermentation SDF, respectively. Additionally, the results suggest that changes in extracellular enzyme activity and nutrient composition during SSF of H. erinaceus are closely associated with the mycelium growth stage, with a mutual promotion or inhibition relationship between the two. Our study offers a foundation for corn husk SDF fermentation and is relevant to the bioconversion of maize processing by-products.

Rheological Characteristics of Wheat Dough Containing Powdered Hazelnuts or Walnuts Oil Cakes

This study assessed edible oil industry byproducts, oil cakes (OC) based on hazelnuts and walnuts (HOC, WOC), to replace wheat flour dough (WD) based on farinograph and extensograph parameters and rheological measurements. The research hypothesis of this work is that replacing part of wheat flour with ground nut oil cakes modifies the rheological characteristics of the dough. WF was replaced at the level of 5%, 10% and 15%. It was shown that use of OC in flour mixtures at various levels significantly influenced the rheological properties of the dough. The water absorption of wheat flour and oil cake mixtures was higher than that of the control sample, and the average value of this indicator was 53.4%. The control sample had the lowest dough development time (DDT), and the presence of HOC or WOC in the system resulted in a significant increase in this parameter (p < 0.05). The average DDT of WDHOC cakes was 4.7 min and was lower compared to WDWOC which was 5.9 min. The WDWOC10% and WDWOC15% samples were characterized by the highest dough stability value and the lowest degree of softening (p < 0.05). The presence of OC in the flour mixtures increased the values of the storage and loss moduli, which was reflected in the K' and K″ values. The values of these parameters also increased as the level of OC addition increased. WDHOC doughs were characterized by higher values of the K' and K″ parameters compared to WDWOC. The results of the creep and recovery test showed that the dough with the addition of nut OC was less susceptible to deformation compared to the control dough (p < 0.05). The resistance to deformation increased with the increasing share of HOC or WOC in the mixtures. The average value of viscoelastic compliance (J1) of this parameter for WDHOC dough was on average 1.8 × 10-4 Pa-1, and for WDWOC 2.0 × 10-4 Pa-1. Nut oil cakes are an interesting technological addition to the dough. Their use may have a positive impact on the characteristics of the finished product and expand their application possibilities in the food industry. This is because the dough with the addition of nut cakes was more stiff and less flexible and susceptible to deformation.

The Rheology and Textural Properties of Bakery Products Upcycling Brewers' Spent Grain

This study aimed to evaluate the rheological properties of doughs with 50% brewers' spent grain (BSG) derived from a rye-based (RBSG) and barley-based (BBSG) beer added, and the textural profile of the related baked products. Simple model systems using BSG flour mixed with water were studied. Two bakery products, focaccia and cookies, were made as food systems using BSG in a 1:1 ratio with wheat flour (WF). Their rheological properties and texture after baking were characterized. BSG-added dough exhibited viscoelastic properties with a solid gel-like behavior. The addition of BSG increased G' > G″ and decreased the dough flexibility. BSG addition in baked RBSG focaccia increased the hardness, gumminess, and chewiness by 10%, 9%, and 12%, respectively. BBSG cookies had a 20% increase in fracturability. A positive correlation was found between the rheological metrics of the dough and the textural parameters of BBSG-added cookies. PCA analysis revealed that complex viscosity, G', G″, and cohesiveness separated BBSG focaccia from RBSG focaccia and the control. Therefore, the rheological properties of BSG dough will have industrial relevance for 3D-printed customized food products with fiber. Adding RBSG and BBSG to selected foods will increase the up-cycling potential by combining techno-functional properties.