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Recent research has primarily focused on strategies for modifying insoluble dietary fiber (IDF) to enhance its performance and functionality. IDF is obtained from various inexpensive sources and can be manipulated to alter its biological effects, making it possible to revolutionize food processing and nutrition. In this review, multiple IDF modification techniques are thoroughly examined and discussed, with particular emphasis on the resulting changes in the physicochemical properties, biological activities, and microstructure of the fiber. An extensive overview of the practical applications of modified IDF in food processing is provided. Our study aims to raise awareness about the vast possibilities presented by modified IDF and encourage further exploration and utilization of this field in the realm of food production. [Display omitted] • The modifications to IDF were summarized. • Changes in physical, chemical, and biological properties of IDF's microstructure. • The application of modified IDF in food processing. [ABSTRACT FROM AUTHOR]

Phenolics in bound form extensively exist in cereal dietary fiber, especially insoluble fiber, while their release profile in gastrointestinal tract and contribution to the potential positive effects of dietary fiber in modulating gut microbiota still needs to be disclosed. In this work, the composition of bound phenolics (BPs) in triticale insoluble dietary fiber (TIDF) was studied, and in vitro gastrointestinal digestion as well as colonic fermentation were performed to investigate BPs liberation and their role in regulating intestinal flora of TIDF. It turned out that most BPs were unaccessible in digestion but partly released continuously during fermentation. 16 s rRNA sequencing demonstrated that TIDF possessed prebiotic effects by promoting anti-inflammatory while inhibiting proinflammatory bacteria alongside boosting SCFAs production and antioxidative BPs contributed a lot to these effects. Results indicated that TIDF held capabilities to regulate intestinal flora and BPs were important functional components to the health benefits of cereal dietary fiber. • 19 bound phenolics (BPs) were found in triticale insoluble dietary fiber (TIDF). • The release profile of BPs in gastrointestinal tract was uncovered in vitro. • The liberated BPs showed noticeable radical scavenging abilities. • BPs in TIDF showed synergetic prebiotic effects with fiber component. [ABSTRACT FROM AUTHOR]

• Alkali enzymatic extraction parameters influenced yield of soluble and insoluble dietary fibre (DF) • Yield of DF depends on concentration of enzyme and extraction time. • Alkali enzymatic extraction altered morphology of extracted soluble and insoluble DF. • Extracted soluble and insoluble DF as an fortificant for development of DF rich porridge. • Implementation of fuzzy analysis of developed DF rich rice porridge. Rice bran is abundant in dietary fiber and is often referred to as the seventh nutrient, recognized for its numerous health benefits. The objective of the current study is to investigate the extraction of both soluble and insoluble dietary fiber from defatted rice bran (DRB) using an alkali-enzymatic treatment through response surface methodology. The independent variables like substrate percentage (5–30 %), enzyme concentration (1–50 µL/g), and treatment time (2–12 h) and dependent variables were the yield of soluble and insoluble DF. The highest extraction yield was observed with alkali enzyme concentration (50 µL/g) treatment, resulting in 2 % SDF and 59.5 % IDF at 24 h of extraction. The results indicate that cellulase-AC enzyme aids in the hydrolysis of higher polysaccharides, leading to structural alterations in DRB and an increase in DF yield. Furthermore, the disruption of intra-molecular hydrogen bonding between oligosaccharides and the starch matrix helps to increase in DF yield, was also confirmed through FTIR and SEM. The extracted DF soluble and insoluble was then used to develop rice porridge. Sensory evaluation using fuzzy logic analysis reported the highest scores for samples containing 0.5 % insoluble DF and 1.25 % soluble DF. [ABSTRACT FROM AUTHOR]

This study was designed to explore the dietary fiber potential of Lycium Barbarum residue, aiming to ascertain its viability as a sustainable dietary fiber source. The study examined the extraction of water-insoluble dietary fiber (LBIDF) from Lycium barbarum residue (LBR) using the enzymatic method. The comparison involved analyzing the monosaccharide composition, microstructure, physicochemical properties, and adsorption properties of LBR and LBIDF. The results indicated that LBIDF possesses the ideal physicochemical properties compared to LBR. Through instrumental analysis, it has been demonstrated that LBIDF possesses a specific structure and functional group of fibers, making it suitable for processing below 300 °C. Furthermore, LBIDF exhibited an optimal functional capacity for cholesterol (41.749 mg/g vs. 31.464 mg/g in LBR), bile acid (30.623 mg/g vs. 19.875 mg/g in LBR), nitrite ion (1159.394 μmol/g vs. 783.261 μmol/g in LBR), glucose (3.552 mmol/g vs. 2.664 mmol/g in LBR), and glucose dialysis retardation index (6.43% vs. 13.52% in LBR). LBIDF can inhibit the digestion of fat and starch in vitro. These findings implied that dietary fiber samples from LBR may offer potential as functional food components. [ABSTRACT FROM AUTHOR]

Insoluble dietary fiber (IDF) isolated through co-fermented bran from probiotics may improve starch gel-based foods. This work aimed to elucidate the comprehensive impact of different IDF samples (CK, unfermented; NF, natively fermented; YF, yeast fermented; LF, Lactobacillus plantarum fermented; and MF, mix-fermented) and their addition ratios (0.3–0.9%) on gel structure-property function. Results indicated that IDF introduction altered the starch pasting behavior (decreased the viscosity and advanced the pasting time). Also, YF, LF, and MF showed less effect on gel multiscale morphology (SEM and CLSM); however, their excessively high ratio resulted in network structure deterioration. Moreover, FT-IR, XRD, and Raman characterization identified the composite gels interaction mechanisms mainly by hydrogen bonding forces, van der Waals forces, water competition, and physical entanglement. This modulation improved the composite gel water distribution, rheological/stress-strain behavior, textural properties, color, stability, and digestive characteristics. The obtained findings may shed light on the construction and development of whole-grain gel-based food products with new perspectives. [Display omitted] • Fermented insoluble dietary fiber (IDF) induces starch pasting behavior changes. • Composite gel multi-scale morphology is regulated by IDF type and addition ratio. • Mixed fermentation IDFs improve optimally under the same addition ratio. • Starch gel functions-processing profiles can enhanced by fermented IDFs. • IDFs modulate gel depending on interaction forces and physical entanglement. [ABSTRACT FROM AUTHOR]

[Display omitted] • IDF extruded at different feed moisture lead different physicochemical properties. • Extruded IDF with the most swelling capacity showed highest fermentability. • Extrusion increased fermentability and boosts all three SCFAs production. • Extrusion created new niches favorable for Bacteroides spp. To investigate the morphological changes of insoluble fiber and their effects on microbiota modulation, particularly Bacteroides , rice bran insoluble fibers were extruded at different feed moisture levels (E20, E40, and E60). The physicochemical properties and SEM revealed that E20 exhibited the highest water holding capacity and displayed the most fragmented edges. E40 had the highest swelling holding capacity and displayed the most lamellar gaps. E60 showed minimal change in physicochemical properties but had a rough surface. After 48h fermentation, E40 showed the highest levels of Bacteroides and SCFAs. E20 and E60 resulted in a modest increase in Bacteroides abundance. SEM showed that bacteria were attached to fragmented edges, loosened lamellar gaps, and rough surfaces of the extruded insoluble fibers. The results suggested that Bacteroides gained a competitive advantage within the extrusion treatment created structural changes. Extrusion treatment can be used to generate specific niches favorable for Bacteroides. [ABSTRACT FROM AUTHOR]

Three environmentally friendly organic acids, acetic acid, citric acid and oxalic acid, were used to treat citrus insoluble dietary fiber (CIDF) in present study, aiming to explore the changes in structural properties as well as their inhibitory effects on starch digestion. The results showed that organic acid treatment significantly reduced the particle size of all three CIDFs, with rougher and folded surfaces, improved crystallinity and thermal stability. During in vitro digestion, it was found that organic acid treatment could increase the particle size and viscosity of digestion, and also effectively enhance the inhibitory ability of α-glucosidase activity, resulting in a further blockage of starch digestion. The starch digestion in oxalic acid-treated group (with 3 wt% addition) was significantly reduced by 18.72 % compared to blank group and 9.05 % compared to untreated. These findings provide evidence of the potential of organic acid-treated insoluble dietary fiber as a functional food. [Display omitted] • The particle size and structure of CIDF were changed after organic acid treatment. • Organic acid treatment enhanced the ability of CIDF to inhibit starch digestion. • Oxalic acid treated group showed the lowest starch digestion and digestion rate (3 wt% addition). • CIDFs can change the structure of α-glucosidase, result in decreased activity. [ABSTRACT FROM AUTHOR]

• A combined dilute alkali and milling process improved functionality of corn fiber. • This corn fiber showed high water retention, swelling, and oil holding capacities. • This corn fiber showed higher short chain fatty acid production than inulin. • The improved property was due to its loose structure and decreased ester linkages. In this study, we developed a process combining dilute alkali (NaOH or NaHCO 3) and physical (disk milling and/or ball milling) treatments to improve the functionality and fermentability of corn fiber. The results showed that combining chemical with physical processes greatly improved the functionality and fermentability of corn fiber. Corn fiber treated with NaOH followed by disk milling (NaOH-DM-CF) had the highest water retention (19.5 g/g), water swelling (38.8 mL/g), and oil holding (15.5 g/g) capacities. Moreover, NaOH-DM-CF produced the largest amount (42.9 mM) of short-chain fatty acid (SCFA) during the 24-hr in vitro fermentation using porcine fecal inoculum. In addition, in vitro fermentation of NaOH-DM-CF led to a targeted microbial shifting to Prevotella (genus level), aligning with a higher fraction of propionic acid. The outstanding functionality and fermentability of NaOH-DM-CF were attributed to its thin and loose structure, decreased ester linkages and acetyl groups, and enriched structural carbohydrate exposure. [ABSTRACT FROM AUTHOR]

The structural, physicochemical, and functional properties of nanofibrillated cellulose (NFC) derived from rice bran (RB), wheat bran (WB), and okara were investigated and explored its potential as novel dietary fibers (DF). Cellulose microfibers (CMF) with cellulose purity of 87.4 % (RB), 92.1 % (WB), and 95.1 % (okara) were prepared by alkali and bleaching treatment, respectively. Subsequently, cellulose microfibers were prepared into NFCs with nanoscale diameters by dynamic high-pressure microjet treatment. Fourier transform infrared (FTIR) spectroscopy demonstrated a significant decrease in the intensity of characteristic absorption peaks of lignin and hemicellulose after chemical treatment. X-ray diffraction results indicated the order of relative crystallinity is: NFC (56.9 %) > CMF (50.8 %) > DF (26.1 %). Moreover, NFC exhibits higher water/oil holding capacity, swelling capability, nitrite/cholesterol/sodium cholate adsorption capacity than CMF and DF. Besides, NFC exhibited superior ability to inhibit starch and lipid digestion compared to DF. Consequently, NFC holds great promise as a novel dietary additive in the food industry. [Display omitted] • Nanofibrillated cellulose were successfully prepared from agricultural crop waste. • The physicochemical properties of NFCs were investigated. • NFC showed excellent adsorption capacities to harmful substances. • NFC exhibited superior ability to inhibit starch and lipid digestion. [ABSTRACT FROM AUTHOR]

Insoluble dietary fiber (IDF) has been widely recognized for its diverse physiological activities, with increased intake being linked to a reduced risk of certain non-communicable diseases. Therefore, a comprehensive analysis of the composition, biological activity, and mechanisms of IDF is crucial for advancing its application in functional foods. There is a growing interest in the role of bound phenolics (BP) associated with IDF in the physiological activities of IDF. This review offers an overview of IDF's physiological activities, explores the interactions between BP and IDF, and discusses how BP enhance IDF's bioactivities. Mechanisms underlying the synergistic effects of IDF and BP are elucidated, and key directions for future research are proposed. IDF demonstrates various physiological activities, including oxidative stress reduction, blood glucose regulation, modulation of gut microbiota composition, and anti-inflammatory effects. The presence of BP, typically associated with IDF through covalent and noncovalent bonds, plays a pivotal role in enhancing the bioactivities of IDF. BP in IDF actively regulate intestinal flora structure and promote IDF metabolism into more short-chain fatty acids (SCFAs), which, alongside BP and metabolites, synergistically exert local or systemic biological activities. Understanding the synergistic effects of IDF and BP provides valuable insights into IDF, contributing to the development of functional dietary fiber foods and dietary interventions aimed at enhancing human health. • Insoluble dietary fiber (IDF) has diverse beneficial physiological activities. • Bound phenolics (BP) combined with IDF via covalent and noncovalent bonds. • BP enhance the bioactivities of IDF through synergistic effects. • BP in IDF work synergistically with IDF by bidirectional regulation with gut flora. [ABSTRACT FROM AUTHOR]

[Display omitted] • Effect of steam explosion treatment (SE) of rice bran on properties of IDF was studied. • IDF showed a lamellar shape and better thermal stability with SE treatment. • The physicochemical properties of IDF from rice bran with SE were enhanced. • The functional characteristics of IDF from rice bran with SE were improved. • The study may be useful for utilization of IDF from rice bran with SE treatment. Rice bran was modified by steam explosion (SE) treatment to investigate the impact of different steam pressure (0.4, 0.8, 1.2, 1.6, and 2.0 MPa) with rice bran through 60 mesh and rice bran pulverization (60, 80, and 100 mesh) with the steam pressure of 1.2 MPa on the structure, thermal stability, physicochemical and functional characteristics of insoluble dietary fiber (IDF) extracted from rice bran. IDF with SE treatment from scanning electron microscopy images showed a porous honeycomb structure, and lamellar shape in IDF became obvious with the increase of steam pressure. The relative crystallinity and polymerization degree of crystalline regions in IDF from rice bran with SE treatment from X-ray diffraction analysis were decreased. Differential scanning calorimetry results showed that thermal stability of IDF with SE treatment increased with the increase of crushing degree. The results of FT-IR also suggested that some glycosidic and hydrogen bonds in IDF could be broken, and some cellulose and hemicellulose were degraded during SE process. The physicochemical and functional characteristics of IDF, including water-holding capacity, oil-holding, glucose adsorption capacity, α-amylase and pancreatic lipase inhibition capacity were decreased with the increase of steam pressure and crushing degree. The swelling and nitrite adsorption capacities of IDF were increased first and then decreased with the increase of steam pressure. The physicochemical and functional characteristics of IDF from rice bran were improved after SE treatment, which might provide references for the utilization of IDF from rice bran with SE treatment. [ABSTRACT FROM AUTHOR]

In this study, we compared the effects of three methods on the structural, physicochemical, and functional properties of insoluble dietary fiber (IDF) in okara: cavitation jet plus ultrasonic treatment (UC), cavitation jet plus alkaline hydrogen peroxide treatment (HC), and cavitation jet plus fermentation with Bacillus subtilis (FC). Compared to UC-IDF, the two types of co-modified IDF showed significant differences in particle size and specific surface area. Structural analyses showed that HC-IDF had a porous structure and complex morphological structure, with a significant increase in the absorption peak area at around 3420 cm−1 and 1051 cm−1, and a significant decrease in thermal stability and crystallinity. Of the three treatments, HC most effectively enhanced the physicochemical and adsorption properties of IDF, including the emulsion stability (84.49% ± 3.5%), water-holding capacity (16.04 ± 0.05 g/g), glucose absorption capacity (53.17 ± 3.44 g/g), cholesterol absorption capacity (32.87 ± 0.89 mg/g), and nitrite absorption capacity (211.7 ± 0.17 μg/g). These results demonstrate the potential of HC-modified okara IDF as a valuable functional food ingredient. Therefore, the cavitation jet combined with alkaline hydrogen peroxide method has a good potential for application in the study of dietary fiber modification. • Cavitation jet (C) improves the function of insoluble dietary fibre (IDF). • C plus alkaline hydrogen peroxide treatment improves IDF properties and adsorption. • HC-modified okara IDF exhibits good hypolipidaemic and hypoglycaemic potential. [ABSTRACT FROM AUTHOR]

[Display omitted] • Pomelo peel insoluble dietary fiber (PIDF) can be used as an effective emulsifier; • Micronization by ball milling cannot fully support emulsifying capacity of PIDF; • Cellulase endowed PIDF emulsibility combined Pickering and 3D network mechanism; • Further ball milling after cellulase made PIDF lose emulsification gradually; • Breakage of intact porous structure of PIDF cause reduced emulsion stability. Emulsion gels from the pomelo peel insoluble dietary fiber (PIDF) were developed. The emulsification potentials of PIDFs subjected to various degrees of ball milling (M−PIDFs), cellulase hydrolysis (C-PIDF), and cellulase hydrolysis followed by ball milling (CM-PIDFs) were evaluated. Emulsions prepared by M−PIDFs for different lengths of ball milling time exhibited similar stability characteristics, confirming that M−PIDF emulsion stability might be determined by the three-dimensional structure formed by M−PIDF stacking and oil droplet capture. C-PIDF had characteristics resembling those of Pickering particles. CM-PIDF emulsions got destabilized with ball milling time prolongation. Interface tension and particle size of C/CM-PIDF decreased gradually during ball milling. Rheological and fluorescence microscopy results revealed that the intact internal crosslinking structure frameworks were disrupted in CM-PIDF emulsions. Therefore, intact fiber-based networks, rather than small particle size or low interfacial tension, determine the stability of PIDF emulsions. This study deepens the understanding of PIDF as a clean emulsifier. [ABSTRACT FROM AUTHOR]

Okara, as a by-product of soybean processing, is rich in insoluble dietary fiber (IDF), which is a carbohydrate polymer with various insoluble polysaccharides. Nowadays, the extraction of IDF with excellent functional properties has become a research hotspot. In this work, we further proposed an alternating alkali/ultrasound method for the efficient extraction of IDF. The sequential treatments of alkali (A-ISF), alkali-ultrasonic (AU-ISF), ultrasonic-alkali (UA-ISF), ultrasonic-alkali-ultrasonic (UAU-ISF) and alkali-ultrasonic-alkali (AUA-ISF) were applied to extract insoluble soybean fiber (ISF). FTIR and XRD results proved the typical structure of ISFs, and TGA results demonstrated the improved thermal stability of UAU-ISF and AUA-ISF. Chemical composition measurement showed that UAU-ISF and AUA-ISF exhibited higher cellulose content (>83 %). SEM results revealed that ultrasonic treatment led to a decomposition of okara matrix and significant porous structure in ISFs with an amplified collapse effect, resulting in an increase of the pore size of ISFs, and strengthening the properties of UAU-ISF and AUA-ISF in higher water (>15 g/g)/oil (>12 g/g) holding capacities, cholesterol binding capacity (>36 mg/g), and cation exchange capacity (>0.3 mmol/g), thus providing new insights for the preparation of ISF with high functional properties that are beneficial for human intestinal health. [Display omitted] • Insoluble soybean fiber was extracted by alternating ultrasonic/alkali treatment. • The prepared insoluble soybean fiber showed higher cellulose content (>83 %). • Alternating ultrasonic/alkali treatment amplified the collapse effect of system. • The functional properties of insoluble soybean fiber were significantly improved. • The extraction mechanism of insoluble soybean fiber was elucidated. [ABSTRACT FROM AUTHOR]

With the rise of sustainable concepts, the beneficial role of soluble dietary fiber in the preparation of clean labelled yogurt has been recognized, but the role of insoluble dietary fiber remains controversial. In this work, the effect of insoluble soybean fiber (ISF) on the rheological and sensory properties of yogurt was investigated based on the improved structural and physicochemical properties of ISF. The results showed that ISF improved the rheological properties of yogurt in a positive concentration-dependent manner. The viscoelasticity was enhanced, with ISF contributing more to the elastic component than to the viscous component. The viscoelastic structure of yogurt was found to be less sensitive to temperature and stress variations and exhibited thermal reversibility. These observations were attributed to the skeletal support of the ISF on the 3D network structure, the facilitation of interactions within the yogurt gel matrix by the ISF and the gel-like network structure of the ISF itself. Creep recovery and thixotropic properties were also improved after the addition of ISF. By analyzing the metrics of rheological properties using principal component analysis, it was found that yogurts with moderate concentrations (0.25%–0.75%, w/v) of ISF were similar to some non-clean-labelled commercial yogurts. Of these, the yogurt containing 0.5% ISF exhibited the best sensory properties. This study provides insight into the development of insoluble dietary fiber and the manufacture of high-quality clean-labelled yoghurt. [Display omitted] • The rheological and sensory properties of yogurt were enhanced by the addition of insoluble soybean fiber (ISF). • Improved interactions and a more elastic network occurred in ISF-added yogurt. • Rheological parameters can be used to predict the textural quality of yoghurt. • ISF is an alternative for preparing clean-labelled yoghurt with desirable properties. [ABSTRACT FROM AUTHOR]

This work investigated the effects and mechanisms of soluble and insoluble dietary fiber (SDF and IDF) on the gelation performance and fishy odors of silver carp surimi. The results showed that the gel properties of surimi increased and then decreased with increasing SDF content, and the best gel properties were achieved at 1 wt% SDF. The gel strength, elasticity and deformation resistance of surimi increased in a dose-dependent manner as affected by IDF, but its effect on viscosity and recovery ratio was similar to SDF. Moreover, 2 wt% SDF and 1 wt% IDF reduced the content and odor activity value (OAV) of most fishy compounds in surimi, and the latter was superior to the former. The rheological characteristics indicated that SDF affected the thermal gelation properties of surimi mainly through filling, concentration and volume exclusion, and IDF mainly through filling, concentration and intermolecular interactions between IDF and myofibrillar protein. Additionally, SDF and IDF inhibited the release of fishy odors by improving the gel network structure and their adsorption, but more SDF (2 wt%) promoted the formation of escape channels for odors release. In summary, 1 wt% IDF could simultaneously improve the gelation performance and fishy odors of silver carp surimi. [Display omitted] • IDF and SDF can improve the gelation performance and fishy odors of surimi. • IDF and SDF content had different effects on the heat-induced gelation of surimi. • IDF affects surimi gel structure by filling, concentration and IDF-MP interactions. • SDF affects surimi gel structure by filling, concentration and volume exclusion. • IDF and SDF inhibit the fishy odor release by improving gel structure and adsorption. [ABSTRACT FROM AUTHOR]

High-pressure microfluidization treatment (HPMT) was performed on the insoluble dietary fiber (IDF) of highland barley bran (HBB), with conditions set at 60 MPa (IDF-60), 120 MPa (IDF-120), and two consecutive high-pressure treatments at 120 MPa (IDF-120-2), respectively. Then the particle size, structural, physicochemical and adsorption properties of different IDF samples were analyzed. After HPMT, the particle size of IDF samples gradiently decreased (p < 0.05), and part of IDF was transferred into soluble dietary fiber (SDF), accompanied by the decrease of hemicellulose and lignin content. In addition, the morphology of the IDF samples became more fragmented and wrinkled, and the two consecutive treatments at 120 MPa significantly damaged the crystalline structure of the IDF. Moreover, the adsorption capacities to water, oil, cholesterol, and NO 2 − were basically enhanced with the increase of treatment pressure and treatment number. The IDF-120-2 sample had the strongest water/oil-holding, swelling, and cholesterol trapping capacities, and the IDF-120 showed strongest NO 2 − trapping capacity (pH = 2). Through the correlation analysis, the adsorption capacities were positively to the particle size and SDF content, and negatively correlated with the specific surface area (SSA) and IDF content. The adsorption capacities of IDF for the four substances were positively correlated with each other. [Display omitted] • Particle size (PS) of insoluble dietary fiber (IDF) decreased after high-pressure microfluidization treatment (HPMT). • HPMT increased the specific surface area (SSA) of the IDF and partially destroyed the crystalline structure of the IDF. • Water/oil holding capacity of modified IDF increased by 46.71% and 54.4%. • Adsorption capacity (AC) of modified IDF for cholesterol and NO 2 - increased by 68.03% and 19.63%. • AC of modified IDF was positively to the PS, SDF content, and negatively to the SSA and IDF content. [ABSTRACT FROM AUTHOR]

• Hemicellulose in the IDF from BSG was significantly degraded after modification. • The modified IDF exhibited reduced particle sizes and more porous structures. • Improved functionalities were found in modified IDF samples. • The modified IDF showed slow in-vitro fermentation performance. Lactic acid (LA)-assisted subcritical water treatment (SWT) was applied to modify the insoluble dietary fiber (IDF) from brewer's spent grain (BSG) for enhancing its functionality and gut fermentability. Modified IDFs were thoroughly characterized for their chemical and structural properties. The results revealed that increasing the treatment temperature and LA concentration reduced hemicellulose content in IDFs from 38.4 % to 0.7 %, alongside a decreased yield (84.8 %–51.4 %), reduced particle size (519.8–288.6 μm), and more porous structure of IDFs. These modifications were linked to improved functionalities, evidenced by the highest water and oil holding capacity increasing by 36 % and 67 %, respectively. Remarkably, the highest glucose adsorption capacity increased by 6.5 folds. Notably, modified IDFs exhibited slower in-vitro fermentation, elevated short-chain fatty acids (SCFAs) production, and a higher proportion of butyrate in SCFAs. These findings highlight the potential of LA-assisted SWT in transforming BSG-derived IDF into a valuable functional food ingredient. [ABSTRACT FROM AUTHOR]

[Display omitted] • Insoluble dietary fibre (IDF) was efficiently modified by ultrasound-microwave (U-M). • U-M reduced the crystallinity of IDF and exposed more hydroxyl groups. • U-M enhanced the in vitro hypoglycaemic activity of IDF. • U-M improved the growth-promoting and adhesion properties of IDF to probiotics. A comprehensive investigation aimed to access the impacts of ultrasonic, microwave, and ultrasonic-microwave synergistic modification on the physicochemical properties, microstructure, and functional properties of corn bran insoluble dietary fiber (CBIDF). Our findings revealed that CBIDF presented a porous structure with loose folds, and the particle size and relative crystallinity were slightly decreased after modification. The CBIDF, which was modified by ultrasound-microwave synergistic treatment, exhibited remarkable benefits in terms of its adsorption capacity, and cholate adsorption capacity. Furthermore, the modification improved the in vitro hypoglycemic activity of the CBIDF by enhancing glucose absorption, retarding the starch hydrolysis, and facilitating the diffusion of glucose solution. The findings from the in vitro probiotic activity indicate that ultrasound-microwave synergistic modification also enhances the growth-promoting ability and adsorbability of Lactobacillus acidophilus and Bifidobacterium longum. Additionally, the level of soluble dietary fiber was found to be positively correlated with CBIDF adsorbability, while the crystallinity of CBIDF showed a negative correlation with α-glucosidase and α-amylase inhibition activity, as well as water-holding capacity, and oil-holding capacity. [ABSTRACT FROM AUTHOR]

Insoluble dietary fiber (IDF) has been characterized to prevent chronic diseases and improve gastrointestinal health, and it has been added to 3D printing plant-based meats (PM) to enhance texture and increase nutritional properties. Therefore, the aim of this study was to investigate the effects of IDF on 3D printing properties and molecular interactions of soy protein isolate (SPI) - wheat gluten (WG) PM. Without the participation of IDF, PM appeared to collapse. When the IDF concentration increased from 0 to 10 %, PM displayed good printing properties, water holding capacity, tensile strength, and elongation at break were increased. Tensile strength and elongation at break reached a maximum at 10 % IDF, and clearly similar results were found for texture attribute indices such as hardness, gumminess, chewiness, and cohesiveness after cooking. All printing inks exhibited shear-thinning behavior and solid-like viscoelasticity, but the structural recovery properties of 3D-printed PM deteriorated when the IDF content was over 10 %. Intermolecular forces indicated that the addition of IDF enhanced the disulfide bonds so that 10 % IDF presented better printing properties. These results indicated the potential for developing PM with dietary fiber functionality through 3D printing technology. [Display omitted] • Developing dietary fiber-enhanced 3D printed plant-based meats. • 10 % IDF addition provides optimal printability and printing accuracy. • An appropriate amount of IDF proportion improves texture and tensile properties. • The addition of IDF promotes the formation of hydrophobic and disulfide bonds. [ABSTRACT FROM AUTHOR]

Mushroom is a high-fiber matrix, with its soluble dietary fiber (SDF) being well identified as prebiotic, leaving the abundant of insoluble dietary fiber (IDF) being overlooked. This study aims to evaluate the functional and structural characteristics of IDF from 5 commercial cultivated mushrooms, to help improve their application. The IDF from the five edible mushrooms constitutes 52.49%–86.13% of the total dietary fiber, primarily composed of cellulose, hemicellulose, lignin, and chitin. Among them, Pleurotus ostreatus IDF (PO-IDF) and Agaricus subrufescens IDF (AS-IDF) displayed remarkable absorption ability, presented by the higher water-holding capacity (12.66 g/g and 12.26 g/g), cholate absorption (26.74 mg/g and 26.94 mg/g), and cholesterol absorption (12.42 mg/g and 12.88 mg/g). These are might attributed to their smaller particle size, larger surface area, rough porous surface and relatively loose structure. FTIR analysis revealed that AS-IDF possesses appreciable O–H groups, which can enhance the adsorption performance of the sample. All these characteristics enable PO-IDF and AS-IDF to adsorb substances both physically and chemically. Notably, AS-IDF exhibited superior antioxidant activity compared to other samples, attributable to its bound polyphenol. All these results raised the possibility of utilizing mushroom IDF as an economically viable functional food ingredient. [ABSTRACT FROM AUTHOR]

Highlights • Ginseng residue was rich in dietary fiber, especially the ginseng-IDF. • Ginseng-IDF was rich in nutrition and chemical composition. • Ginseng-IDF presented good physicochemical properties and adsorption function. • Ginseng-IDF could be served as a promising functional food ingredient. Abstract The insoluble dietary fiber from ginseng residue (ginseng-IDF) was extracted using the AOAC (Association of Official Analytical Chemists) method with content of 68.61%. Ginseng-IDF had a polysaccharide content of 18.87%, uronic acid content of 7.85%, protein content of 6.52%, and had ideal water-holding capacity (17.66 g/g), swelling ability (15.05 mL/g), and oil-holding capacity (1.78 g/g). Scanning electron microscope, Fourier transform infrared spectroscopy, and X-ray diffraction analyses suggested that ginseng-IDF had the typical structures of hydrolysis fiber, polysaccharide functional groups, and crystal structure of cellulose. Different fiber components give ginseng-IDF a specified range of pyrolysis temperature, and it is suitable for application in food processing lower than 300 °C. In addition, ginseng-IDF exhibited notable glucose and sodium cholate adsorption, significantly improved nitrite adsorption at pH 2.0 and cholesterol adsorption at pH 7.0. The above results show that ginseng-IDF could be used as an ideal functional ingredient in food processing. [ABSTRACT FROM AUTHOR]

Abstract To improve its functional properties, insoluble fiber of bamboo shoot shell (BIDF) was modified by enzymatic hydrolysis and dynamic high pressure micro-fluidization (DHPM). The results showed that, after enzymatic hydrolysis and DHPM treatment, the significantly decreased particle sizes and the marked microstructural changes of BIDF powders were noticed, especially for a honey-comb appearance and large cavities were clearly visible on the surface of DHPM-modified fiber. Crystallinity and thermal stability of modified fibers increased, due to the fact that part of lignin and hemicellulose were removed during the treatments, which was further confirmed by the FT-IR spectra. Compared with unmodified and enzymatic hydrolyzed fibers, DHPM-modified fiber had not only higher water holding capacity, but also more promising binding capacities for oil, nitrite ion, glucose and cholesterol, which might dependent on its decreased particle size and porous structure. The present study suggested that DHPM modification could effectively improve functional properties of BIDF, which promotes its use in food applications. Highlights • Insoluble dietary fiber extracted from bamboo shoot shell (BIDF) was modified by enzymatic hydrolysis and DHPM. • The treatments significantly decreased the particle sizes of BIDFs and changed their microstructure. • Modified fibers exhibited better physicochemical and physiological properties. • DHPM is a promising method for the modification of BIDF, which promotes its use in food applications. [ABSTRACT FROM AUTHOR]

[Display omitted] • Insoluble dietary fiber (IDF) apparently reduced starch digestion rate and content. • IDF was a mixed-type (competitive and non-competitive) inhibitor to a -amylase. • α -Amylase could bind to IDF by hydrogen bonding and van der Waals forces. • IDF changed the structure of α -amylase, leading to reduction in enzyme activity. This study investigated effects of insoluble dietary fiber (IDF) from wheat bran on starch digestion in vitro , analyzed the inhibition kinetics of IDF toward α -amylase and discussed the underlying mechanisms. Digestion results showed IDF significantly retarded starch digestion with reduced digestion rate and digestible starch content. Enzyme inhibition kinetics indicated IDF was a mixed-type inhibitor to α -amylase, because IDF could bind α -amylase, as evidenced by confocal laser scanning microscopy. Fluorescence quenching and UV–vis absorption experiments conformed this, found IDF led to static fluorescence quenching of α -amylase, mainly through van der Waals and/or hydrogen bonding forces. This interaction induced alternations in α -amylase secondary structure, showing more loosening and misfolding structures. This may prevent the active site of enzyme from capturing substrates, contributing to reduced α -amylase activity. These results would shed light on the utilization of IDF in functional foods for the management of postprandial blood glucose. [ABSTRACT FROM AUTHOR]

[Display omitted] • Mixed SSF via CZ-6 and CZ-7 effectively facilitated the BP release. • The biotransformation pathways of BP were partially speculated. • The Cellulase, β-glucosidase and Filter paper lyase activities were correlated with the BP content. • The SEM indicated the fiber structure was damaged by mixed SSF. • The BP released by mixed SSF owned better inhibition ability of carbohydrate hydrolase. The purpose of this work was to investigate the release characteristic of bound polyphenols (BP) from tea residues insoluble dietary fiber (IDF) by mixed solid-state fermentation (SSF) with cellulose degrading strains CZ-6 and CZ-7. The results implied that cellulase, β-glucosidase and filter paper lyase activities were strongly correlated with the BP content. The scanning electron microscop and fourier transform infrared spectroscopy manifested that the cellulose network of the IDF was decomposed and dissolve, forming more loose fibrous structure. Additionally, 28 polyphenols components were detected and their biotransformation pathways were preliminary speculated. Moreover, the BP obtained by mixed SSF produced prominent inhibitory activities against α-glucosidase and α-amylase, as well as exhibited significant scavenging effects on DPPH•, ABTS+• free radicals and ferric reducing antioxidant power. These findings could further promote the utilization of BP from agricultural by-products in a more natural and economical method, CZ-6 and CZ-7 strains provide a new approach to expound the release and conversion of BP. [ABSTRACT FROM AUTHOR]

[Display omitted] • Cell-scale fiber increased protein aggregation and starch gelatinization rate. • Cell-scale fiber decreased gluten malleability and starch thermal stability. • Fiber addition weakened the interaction between water and macromolecules. • Cell- and tissue-scale fiber differently affected spatial orderliness of protein. • Milling fiber to cell scale was conducive to improve the dough and noodle quality. Superfine grinding of insoluble dietary fiber (IDF) is a promising method to improve the product quality by regulating the interaction between protein and starch. In this study, the effects of buckwheat-hull IDF powder, at cell-scale (50–10 μm) and tissue-scale (500–100 μm), on the dough rheology and noodle quality were investigated. Results showed that cell-scale IDF with higher exposure of active groups increased the viscoelasticity and deformation resistance of the dough, due to the aggregation of protein–protein and protein-IDF. Compared with the control sample, the addition of tissue-scale or cell-scale IDF significantly increased the starch gelatinization rate (β, C3-C2) and decreased the starch hot-gel stability. Cell-scale IDF increased the rigid structure (β-sheet) of protein, thus improving the noodle texture. The decreased cooking quality of cell-scale IDF-fortified noodles was related to the poor stability of rigid gluten matrix and the weakened interaction between water and macromolecules (starch and protein) during cooking. [ABSTRACT FROM AUTHOR]

[Display omitted] • To improve the okara insoluble dietary fibre performance was developed. • A cavitation jet combined with enzyme treatment-method (A-IDF) was applied. • A-IDF was compared with other treatment strategies. • This method can greatly valorise the okara. In this study, a new composite modification method utilizing a cavitation jet combined with a composite enzyme (cellulase and xylanase) was developed to modify the insoluble dietary fibre (IDF) of okara (IDF was first treated with the cavitation jet at 0.3 MPa for 10 min, and then 6% of the enzyme was added, the composite enzyme with a 1:1 enzyme activity was hydrolysed for 1.5 h to obtain the modified IDF), and explored the structure–activity relationship between the structural properties, physicochemical properties and biological activities of IDF before and after modification. Under the action of cavitation jet and double enzyme hydrolysis, the modified IDF had a wrinkled and loose porous structure, which improved the thermal stability. Its water holding capacity (10.81 ± 0.17 g/g), oil holding capacity (4.83 ± 0.03 g/g) and swelling capacity (18.60 ± 0.60 mL/g) were significantly higher than those of unmodified IDF. In addition, compared with other IDFs, the combined modified IDF had greater advantages in nitrite adsorption (13.75 ± 0.14 μg/g), glucose adsorption (6.46 ± 0.28 mmol/g) and cholesterol adsorption (16.86 ± 0.83 mg/g), and improved in vitro probiotic activity and in vitro anti-digestion rate. The results show that the cavitation jet combined with compound enzyme modification method can effectively improve the economic value of okara. [ABSTRACT FROM AUTHOR]

The high purity insoluble dietary fiber (IDF) from okara is a natural component with a potentially positive effect on a high-fat diet (HFD)-induced hepatic metabolic disorders, although its regulatory mechanism remains unclear. This study aims to elucidate the potential pathways and key proteins of IDF for the amelioration of hepatic lipid metabolism in mice fed with HFD. Here, we used label-free quantitative proteomics technology to quantity and identify differentially expressed proteins in the liver that are associated with IDF treatment. The differentially expressed proteins were assessed by GO annotation and KEGG pathways. Western blot and qRT-PCR analyses were conducted to validate the potential targets regulated by IDF. In total, 73 differentially expressed proteins were identified, of which 27 were up-regulated (FC > 1.5) and 46 were down-regulated (FC < 0.667). GO analysis suggested that differentially expressed proteins were mainly located in the cell and organelles, regulated biological processes, and were associated with enzyme activity and molecular binding. The KEGG pathway enrichment analysis further demonstrated glycolysis/gluconeogenesis, pyruvate metabolism, TCA cycle, arginine biosynthesis, alanine, aspartate and glutamate metabolism, and retinol metabolism were affected. The combination of proteomics, Western blot, and qRT-PCR suggested that ACS, ACLY, GOT1, GLS2, NAGS, CYP4A10, CYP3A25, and CYP2A5 in these pathways might be key proteins for IDF intervention. Taken together, our findings elucidate new mechanisms involved in how IDF affects hepatic metabolism, provide important information for the functional food industries, and improve the added value of okara. Okara is evidenced as a high-quality by-product with several nutritional components, especially dietary fiber (50–60%) labeled as "The Seventh Nutrient". Previous studies have shown that IDF has a positive potential effect on a high-fat diet (HFD)-induced hepatic metabolic disorders, but its molecular mechanism remains unclear. To elucidate the therapeutic mechanism of IDF at the protein level, a label-free quantitative proteomic analysis was used to identify the dynamic changes of the liver proteome between HIDF and HFD groups in this study. These results provide a new perspective for exploring the therapeutic mechanism of IDF at the protein level and enlightenment for promoting the comprehensive utilization of okara. [Display omitted] • Proteomic analysis reveals the potential mechanisms of IDF from okara on hepatic lipid metabolism in high-fat diet fed-mice. • We identified 27 up-regulated and 46 down-regulated differentially abundant proteins. • These proteins were related to lipid and glucose homeostasis, amino acid biosynthesis and metabolism, and energy metabolism. • Eight proteins in were verified by western blot and qRT-PCR analysis. [ABSTRACT FROM AUTHOR]

Effects of thermal pre-treatment on physicochemical properties of okara insoluble dietary fiber (IDF) during wet media milling were studied. During the milling process, control sample (without pre-treatment) showed the largest mean particle size, followed by samples under pre-treatment temperature at 80 °C, 100 °C and 120 °C, respectively. The minimum size (298.17 nm) was obtained under the temperature of 120 °C and milling time of 6 h. The IDF samples subjected to thermal pre-treatment showed disintegrated and irregular surfaces, and were presented in agglomerated form with puffed morphology after subsequent milling for 6 h. Fourier transform infrared spectroscopy and X-ray diffraction analysis revealed the modification of structural characteristics and the degradation of IDF components after thermal pre-treatment and wet milling. As the milling duration prolonged, water soluble index, Zeta potential and apparent viscosity of all the samples decreased, while swelling power abruptly increased and then gradually dropped. [ABSTRACT FROM AUTHOR]

In order to efficiently utilize mushroom-processing waste discharge, insoluble fiber (FVIF) from aged Flammulina velutipes stipe was prepared with a series of wet milling steps of colloid mill (CM), PFI, low pressure homogenization (LPH) and high pressure homogenization (HPH) and formed into film by casting method. The SEM images depicted that morphology and size of FVIF varied (fibrous to spherical; 5 um to 50 nm) with a tendency of uniform and micronization as homogenization intensity increased. Accordingly, HPH-fiber film presented a smoother surface and more compact internal structure, especially a higher tensile strength (49.83 ± 3.63 MPa) and a better barrier property to water vapor (0.095 ± 0.003 a  g·mm/m 2 ·h·kPa) and oxygen (9.96 ± 0.63 meq/kg). Moreover, HPH benefited the film's thermal stability, color and transparency. It confirmed that film performance is closely associated with fiber morphology and HPH provides a potential approach to develop new edible film from mushroom byproducts. [ABSTRACT FROM AUTHOR]

Insoluble dietary fiber (IDF) was commonly present in feedings during extrusion for preparing plant protein-based meat analogs. The aim of this study was to investigate the feasibility of using IDF to improve the fibrous structure of high-moisture extrudates (HME) produced from soybean protein isolate (SPI). The structures of extrudates were analyzed visually and using confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM). The mechanical properties of extrudates were determined by a texture analyzer. The CLSM and SEM images of SPI-IDF extrudates presented a clear interface between the SPI and IDF domains, which indicated that the IDF phase dispersed within the SPI phase reduce the mutual cross-linking between SPI. The substitution of 10%–20 wt% IDF promoted the formation of an SPI matrix/IDF filler mesh structure, which could contribute to the fibrous appearance and higher mechanical anisotropy. Substitution of more IDF in SPI resulted in a collapsed structure, possibly due to macroscopic phase separation during extrusion. It can be concluded that the partial substitution of SPI with IDF can promote the formation of a fibrous structure with enhanced mechanical anisotropy. [Display omitted] • The addition of IDF in SPI enhances the mechanical anisotropy of extrudates. • IDF facilitates the formation of filamentous structures in extrusion. • IDF addition increases the storage modulus of SPI-IDF blends. • Phase separation of SPI and IDF is likely to occur during extrusion. [ABSTRACT FROM AUTHOR]

[Display omitted] • LESIDF significantly improved the WHC and gel strength of MP gels. • The addition of LESIDF changed chemical forces and water distribution of MP gels. • LESIDF promoted the conversion of β-sheets to α-helices. • MP gels containing 2.5%-3.0% LESIDF had the best properties. This paper investigated the effects of Lentinus edodes stipes insoluble dietary fiber (LESIDF, 0%-3.0%) on the quality and microscopic properties of pork myofibrillar protein (MP) gels. The results showed that the water holding capacity and gel strength of composite gels enhanced with increasing LESIDF (1.0%–2.5%), and reached the maximum at the level of 2.5%–3.0%. Disulfide and non-disulfide covalent bonds were major chemical forces maintaining the 3D network of LESIDF-MP composite gels. LESIDF also promoted the formation of ionic and hydrogen bonds, confirmed by the self-assembly of β-sheets to α-helices, leading to a compact gel network structure. The observation of paraffin section revealed that LESIDF could capture more water molecules in gels, which was consistent with the transformation of free water to immobilized water. Overall, the optimal addition of LESIDF was 2.5%-3.0%, which provided a good strategy for LESIDF as an agricultural by-product to improve the quality of gel meat products. [ABSTRACT FROM AUTHOR]

[Display omitted] • The structure and composition of three IDF were changed after ball milling (BM). • BM increased the glycolipid adsorption capacity of three IDF. • BM enhanced three IDF's ability to inhibit the digestion of starch and fat. • BM improved glucose tolerance and inhibited the rise of blood lipid in mice. The effects of ball milling processing on the structure, physicochemical, and functional properties of insoluble dietary fiber (IDF) in bran from prosomillet, wheat and rice were investigated. Meanwhile, the effect of IDF on glucose tolerance and blood lipid levels in mice was evaluated as well. With findings, for all three grains, the particle sizes of IDF were significantly reduced after ball milling treatment (p < 0.05). Scanning electron microscopy revealed fragmented fiber with numerous pores and cracks. The reactive groups of three IDF samples were found to be similar by fourier transform infrared spectroscopy. And consistent with X-ray diffraction and thermal analysis, for all three grains, ball milling reduced the crystallinity of IDF and helped to increase the release of free phenol by 23.4 %, 8.9 %, and 12.2 %, respectively. Furthermore, the water holding capacity, glucose delay capacity, glucose, sodium cholate, and cholesterol adsorption capacity, and in vitro digestibility of starch and fat were all improved to varying degrees. Animal experiments showed that ball milling treatment effectively slowed the postprandial rise in blood sugar (especially IDF of rice bran) and blood lipids (especially IDF of prosomillet bran). As a result, ball milling treatment is a potential method for dietary fiber modification in the food industry. [ABSTRACT FROM AUTHOR]

[Display omitted] • PUIDF had good water retention, oil retention, swelling and glucose and cholesterol adsorption performance in vitro. • PUIDF intake reduced serum levels of TC, TG, LDL-C and increased the HDL-C level in obese mice. • PUIDF treatment effectively prevented the HFD-induced decline of gut microbiota abundance in mice. • PUIDF treatment significantly modulated the gut microbiota composition disturbed by the HFD. In this study, IDF from Pyrus ussuriensis Maxim pomace (PUIDF) was prepared, and its routine constituents as well as physicochemical properties and structure were analyzed. Moreover, the effect of PUIDF on obesity and gut microbiota (GM) through a high-fat diet (HFD) mouse model was investigated. The results demonstrated that PUIDF had a loose and porous surface structure and typical cellulose polysaccharide functional groups with good water holding, oil holding and swelling capacity, as well as glucose and cholesterol adsorption performance in vitro. PUIDF could significantly reduce weight gain and lipid and cholesterol levels in HFD-induced obese mice. More importantly, PUIDF intervention greatly improved the diversity of GM in mice, as well as regulated intestinal microbiota composition and increasing the abundance of short-chain fatty acid producing bacteria. These results suggest that PUIDF may have a positive effect to alleviate hyperlipidemia and improve intestinal bacterial ecosystems. [ABSTRACT FROM AUTHOR]

In industrial processing of the avocado (Persea americana Mill.) fruit only the pulp is used, resulting in thousands of tons of seeds as a waste by-product. Chemical and technological characterizations were done on fiber residues produced with one of two fiber extraction methods: Method A, using NaHS03; and Method B, using NaHS03, NaCl and trishydroxymethyl- aminomethane. Proximate composition, total, soluble and insoluble dietary fiber, acid and neutral detergent fiber, acid detergent lignin, cellulose and hemicellulose were determined. Also, technological properties were evaluated on fiber residues. The main results were: yield did not differ (p>0.05) between methods (A: 45.63%; B: 48.11%), but they did differ (p<0.05) in ash, moisture and nitrogen-free extract. The residues' relatively high proportions of soluble dietary fiber, neutral detergent fiber and hemicellulose allowed them to retain four times their weight in water and six times their weight in oil. The properties of avocado seed fibrous residues make them promising technological ingredients in industrial food systems. [ABSTRACT FROM AUTHOR]

Modification of insoluble dietary fiber (IDF) for facilitating its applications has been encouraged in food industry. IDF from soybean residues was treated by dynamic high pressure microfluidization (DHPM), and effect of modified IDF (MIDF) addition on gelatinization and rheology of rice starch (RS) was investigated. It was found that DHPM could effectively reduce particle size of IDF, induce puffed morphology, and increase their water holding capacity. Addition of IDF/MIDF to RS increased peak and final viscosity of paste, and MIDF decreased breakdown and setback value, indicating MIDF may be a great candidate for increasing stability of paste and restraining short-term retrogradation of starch gels. Dynamic rheology indicated that supplementing MIDF changed rheological properties of RS less than IDF did. The results suggested that DHPM would provide an opportunity to change the physicochemical properties of IDF, and the resulting MIDF may be more suitable for designing fiber-enriched products. [ABSTRACT FROM AUTHOR]

The in vitro hypoglycemic properties of three different sulfuric acid (H 2 SO 4 ) modified rice bran insoluble fibers (SMRBIFs) produced using 0.2% (0.2%-SMRBIF), 1.25% (1.25%-SMRBIF), 2.0% (2.0%-SMRBIF) (w/v) H 2 SO 4 in combination with 1.25% potassium hydroxide (KOH) respectively, were investigated. The results revealed that all the three RBIFs have strong glucose adsorption capacity and α-amylase inhibition activity, with 1.25%-SMRBIF being the most effective one. The glucose adsorption capacity increased with increasing porosity and specific surface area of the SMRBIFs, and the maximum glucose bound amount increased by 2–3 folds for acid-alkaline treated RBIFs compared to untreated material. The α-amylase inhibition activity of RBIF was associated with the formation of amylase-RBIF complex as confirmed by fluorescence spectroscopy, with the highest amylase activity inhibitory (24.72%) for 1.25%-SMRBIF. However, the glucose diffusion was retarded a bit stronger by these RBIFs compared to the untreated rice bran, which might be attributed to their larger specific surface area. Therefore, it was suggested that the concentration of postprandial serum glucose lowered by RBIF was mainly ascribed to binding glucose and retarding α-amylase action. [ABSTRACT FROM AUTHOR]

Insoluble fibers are not commonly used as emulsion stabilizers because of their compact physical structure and strong hydrophilicity. In this study, pomelo insoluble fibers (PISFs) prepared via cellulase hydrolysis and cellulase hydrolysis followed by octenyl succinic anhydride esterification were used as emulsifiers. The fabricated fibers are denoted as MPISF and OMPISFs, respectively. Unlike MPISF, the OMPISFs with different degrees of substitution (i.e., OMPISF(I) and (II)) increased in the ζ-potentials and contact angles but decreased in the oil-water interfacial tensions to different degrees. Furthermore, an 0.5 wt% OMPISF(II) content was required to prepare a stable non-creaming emulsion, whereas the corresponding MPISF and OMPISF(I) contents were 0.75 wt%. The OMPISF(II)-stabilized emulsions did not undergo creaming after three freeze-thaw treatment cycles. Therefore, the properties of the OMPISF(II)-stabilized emulsions were superior to those of the MPISF- and OMPISF(I)-stabilized emulsions. Additionally, the final amount of free fatty acids released by the OMPISF(II)-stabilized emulsion was 13.3% lower than that released by the MPISF-stabilized emulsion during simulated gastrointestinal digestion. During lipid oxidation processes, the amounts of lipid hydroperoxide and thiobarbituric acid reactive substance produced in the OMPISF(II)-stabilized emulsion were 41.3% and 40.0% lower, respectively, than those in the MPISF-stabilized emulsion. OMPISFs improved the emulsion properties by increasing the oil–water interface stability, forming more solid three-dimensional structures, and promoting electrostatic repulsion between emulsion droplets. These findings indicate that pomelo peel dietary fiber is a promising emulsifier with excellent application potential for the preparation of emulsion stabilizers. [Display omitted] • Dual modification of OSA and cellulase endowed PISF an excellent emulsibility. • Freeze-thaw, digestion and oxidative stability of emulsions were improved by OSA. • Higher DS provide emulsions with higher stabilization and application properties. • Improved network, interface layer and electrostatic value were the main mechanism. • This study facilitates the development of utilization of pomelo peel as emulsifier. [ABSTRACT FROM AUTHOR]

Cadmium (Cd) is a toxic heavy metal and leads to various altered physiological functions, which are harmful to health. This study aimed to evaluate the protective effect of insoluble dietary fiber from rice bran (RBIDF, non-starch polysaccharides) against Cd-induced toxicity in mice. The results showed that Cd exposure caused a significant decrease in body weight and that RBIDF recovered the body weight gain of mice (P < 0.05). Moreover, RBIDF reversed the decrease of liver and kidney weight, and the increase of serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), creatinine (CREA) and urea (UREA) levels. The histopathological results showed that RBIDF alleviated severe liver damage induced by Cd exposure, and improved liver cell injury and glomerulus destruction. RBIDF also decreased the Cd accumulation in the intestine and Cd absorption and increased Cd content in mouse feces (P < 0.05). In addition, at phylum level, RBIDF increased Bacteroidetes abundance, while decreased Firmicutes and Proteobacteria abundances. At genus level, it increased Lactobacillus abundance as well. It could be seen that RBIDF ameliorated the Cd-induced decrease in gut microbiota disorders. The results indicated that RBIDF was an effective component in the daily diet against Cd toxicity. [Display omitted] • RBIDF ameliorated liver and kidney damage caused by cadmium. • RBIDF maintained body weight and promoted the excretion of feces of cadmium. • RBIDF restored bacterial community structure and composition of gut microbiota. [ABSTRACT FROM AUTHOR]

IDF was extracted by alkaline hydrogen peroxide (named BIDF) and complex enzymatic hydrolysis method (named OIDF) from bamboo. The in vitro fecal fermentation characteristics of BIDF, OIDF and commercial bamboo fiber BF90 and their impacts on human gut microbiota were studied for the first time. Results showed that BIDF, OIDF and BF90 could promote the production of total SCFAs after 24h fermentation. Additionally, BIDF could alter the composition and microbial diversity of gut microbiota, especially increase the relative abundance of Bacteroides and decrease the ratio of Firmicutes to Bacteroidetes (F/B) value. These results revealed that the IDF from bamboo could be partially utilized by specific bacteria in human intestines and provide a reference for the study of the effects of IDF fermentation on SCFAs production and microbial composition. [Display omitted] • Two high-quality insoluble dietary fiber was obtained from Bamboo culm uesd by alkaline hydrogen peroxide (named BIDF) and complex enzymatic hydrolysis method (named OIDF), respectively. • During in vitro fecal fermentation, both BIDF and OIDF could promote the production of short-chain fatty acids (SCFAs). • BIDF could regulate the composition and microbial diversity of gut microbiota. • The insoluble dietary fiber from bamboo can be utilized by specific bacteria in human intestines. Bamboo contains abundant hemicellulose, cellulose, and lignin, which are a high-quality insoluble dietary fiber (IDF) raw material. To investigate IDF- induced changes in the production of short-chain fatty acids (SCFAs) and the composition of human gut microbiota, IDF was extracted by alkaline hydrogen peroxide (named BIDF), complex enzymatic hydrolysis method (named OIDF) from bamboo, and commercial bamboo fiber BF90. The in vitro fecal fermentation characteristics of BIDF, OIDF, BF90 and its impacts on human gut microbiota were studied for the first time. Results showed that BIDF, OIDF, and BF90 could promote the production of total SCFAs after 24 h fermentation. Additionally, BIDF could alter the composition and microbial diversity of gut microbiota, especially increase the relative abundance of Bacteroides and decrease the ratio of Firmicutes to Bacteroidetes (F/B) value. These results revealed that the IDF from bamboo could be partially utilized by specific bacteria in human intestines and provide a reference for the study of the effects of IDF fermentation on SCFAs production and microbial composition. [ABSTRACT FROM AUTHOR]

[Display omitted] • Fiber-bound polyphenols from various whole grains effectively scavenge carbonyls. • High carbonyl trapping capacity can be retained after gastrointestinal digestion. • The carbonyls adduct of fiber-bound polyphenols were detected. The carbonyl trapping activity of bound-polyphenol rich insoluble dietary fiber (BP-IDF) from different whole grains and underlying mechanism of these BP-IDF actions were studied under simulated physiological conditions. We found that the black highland barley BP-IDF exhibited the most pronounced effect in scavenging carbonyls by trapping 88.7%, 72.2%, 95.7%, and 31.4% for methylglyoxal, glyoxal, acrolein, and malondialdehyde within 24 h, respectively. After vitro gastrointestinal digestion, the black highland barley BP-IDF still retained considerable trapping activity for carbonyls. The carbonyl scavenging capacity was reduced by up to 93% after removing bound polyphenols from the black highland barley BP-IDF, which was consistent with the reduction in its total phenolic content. Moreover, the formation of adducts between reactive carbonyl species (RCS) and polyphenols bound to insoluble dietary fiber (IDF) was also detected. Overall, these findings confirmed that IDF-bound polyphenols were still active to trap RCS, indicating the potential benefits of BP-IDF from whole grains as functional ingredients to limit carbonyl stress across the gastrointestinal tract. [ABSTRACT FROM AUTHOR]

Abstract: The influence of the ratio of soluble dietary fiber (SDF) and insoluble dietary fiber (IDF) on the in vitro starch digestion, predicted glycemic index (pGI), and the physicochemical properties of fiber-enriched cakes were evaluated. The hydration and pasting properties were affected by the ratio of SDF and IDF. According to the increase of IDF ratio (SDF ratio reduction) in 3g fiber-enriched cakes, slowly digestible starch (SDS) contents increased, while the rapidly digestible starch (RDS) contents decreased. The pGI values were significantly different with control in 3g fiber-enriched cake containing more than 50% IDF contents (p <0.05). But the pGI values of 6g fiber-enriched cake samples were not significantly different by SDF and IDF ratio. With the exception of the SDF 100% cake, volume index, hardness, and color values of the fiber-enriched cakes increased according to reductions in the SDF ratio. The cakes containing 3g of total dietary fiber (the same ratio of SDF and IDF) per serving were shown to have low pGI and acceptable quality attributes. Specially, total dietary fiber amount and IDF ratio are more effective than SDF ratio to lower the pGI value. [Copyright &y& Elsevier]

Abstract: The effects of microfluidization on the characteristics and physicochemical properties of insoluble dietary fiber (IDF) from peach and oat were investigated. The results showed that microfluidization could effectively reduce IDF particle sizes to submicron scales, trigger a redistribution of some fiber composition from insoluble to soluble fractions and improve the physicochemical properties (water-holding capacity, swelling capacity, oil-holding capacity) of IDF to some different extents. After microfluidization the IDF ability in lowering postprandial serum glucose (including the effects of IDF on the diffusion of glucose, glucose adsorption capacity and inhibitory effects of IDF towards α-amylase) and the activity of pancreatic lipase generally increased. It was concluded that microfluidization treatments could effectively improve the functionalities of IDF, which might be a potential fiber-rich ingredients in functional foods. [Copyright &y& Elsevier]

Emerging evidence suggests that insoluble dietary fiber prevents obesity by regulating gut dysbiosis. However, whether insoluble yeast β-glucan (IYG) has an anti-obesity effect is still unclear. Here, the impact and potential mechanism of long-term IYG supplementation on high-fat diet (HFD)-induced obesity were investigated. After 24 weeks of long-term supplementation, IYG ameliorated weight gain, dyslipidemia, systemic inflammation, glucose intolerance and insulin resistance in HFD-fed rats. In addition, HFD-induced gut dysbiosis and changed levels of short-chain fatty acids and lipopolysaccharide were restored by IYG. Meanwhile, HFD-induced downregulations of tight junction proteins and Mucin 2 as well as elevated gut permeability were recovered by IYG. IYG also mitigated HFD-induced colonic inflammation and oxidative stress. Moreover, antibiotic treatment abrogated the protective effect of IYG on obesity, indicating the important role of gut microbiota in IYG's effect. This study demonstrated that IYG, as a potential prebiotic, exhibited a protective effect on HFD-induced obesity. [Display omitted] [ABSTRACT FROM AUTHOR]

Abstract: Xylooligosaccharides (XOS) were prepared from wheat bran insoluble dietary fiber (WBIDF) by treatment with commercial xylanase preparation Sunzymes. XOS, with a purity of 95% (w/w) and degree of polymerization of 2-7 and the ratio of arabinose to xylose of 0.27, was obtained with a yield of approximately 31.2% of WBIDF. Their stability was evaluated by comparing with that of commercial fructooligosaccharides (FOS) during pasteurization (60–100°C, 30min) and autoclave sterilization (121°C, 1kg/cm2, 10–50min) at pH 2.0–4.0. XOS was characterized by a high thermal stability during pasteurization at pH 2.5–4.0 and sterilization at pH 3.0–4.0. Even at pH 2.0, the remaining XOS reached 97.2% (w/w) and 84.2% (w/w) during pasteurization (100°C, 30min) and sterilization (50min), respectively. Compared with FOS, XOS was strongly resistant to lower acidic conditions. The results revealed that XOS was considered to be more suitable for use as functional food ingredients. [Copyright &y& Elsevier]

Background: Cadmium (Cd) is a representative pernicious metal, which has high biological toxicity. Its precaution through dietary administration is considered an important strategy. Considering that Portulaca oleracea L. (Por.L) has antioxidant, anti-inflammatory and other high medicinal value, and purslane insoluble dietary fiber (PIDF) has good binding property to metal ions, they could be good methods for Cd-induced biotoxicity therapy.Purpose: To investigate the beneficial effects of Por.L or PIDF against Cd-induced subchronic toxicity and identify its underlying mechanisms.Study Design and Methods: C57BL/6 male mice (n = 12) were received 100 mg l-1 CdCl2 in water for 8 weeks. Mice were divided into four groups: Control, Cd-treated, 8% Por.L + Cd, and 8% PIDF + Cd. Histological evaluation, inductively coupled plasma-mass spectrometry, western blotting analysis, quantitative real time-PCR, gas chromatography-mass spectrometry and 16S rDNA analysis were used in the study.Results: Por.L treatment was able to inhibit inflammation and accumulation of Cd, enhance the activity of antioxidant enzymes, increase beneficial bacterial species of Akkermansia and Faecalibaculum and suppress the production of inflammatory cytokines in the colon, such as TNF-α, IL-6, IL-1β and IFN-γ. PIDF mainly relieved the toxicity of Cd by increasing the production of short chain fatty acids with anti-inflammatory functions and repressing the liver and kidney inflammation mediated by the TLR4/ MyD88/NF-κB pathway.Conclusion: Our study has demonstrated that the antagonistic-Cd effects of Por.L might be mediated via chelation, antioxidation, regulation of intestinal microecology. Thus, our study provides a novel insight into Por.L as a promising function food for the anti-Cd biotoxicity. Por.L supplement could be considered as a potential coping strategy to alleviate hazardous effects in Cd-exposed humans. [ABSTRACT FROM AUTHOR]

The aim of the study is to improve the physicochemical and Cd(II) adsorption properties of rice bran insoluble dietary fiber (RBIDF). Dynamic high pressure microfluidization (DHPM) (0–150 MPa for 2 times) was investigated as a modification process for RBIDF, determining its effects on physicochemical, structural and Cd(II) adsorption properties. After a 30 MPa treatment, the flake-like surface of RBIDF changed into a fluffy and slightly expanded morphology. However, DHPM-treated RBIDFs at 60, 90 MPa were fragmented and separated into smaller chips. DHPM increased the RBIDF specific surface area and total negative charge. Among all samples, DHPM-treated RBIDF at 150 MPa exhibited the highest Cd(II) adsorption capacity (60.5 μmol/g at pH 2.0), which was 1.46 times that of the untreated sample. Cd(II) adsorption was well described by the pseudo-second-order kinetics and Langmuir isotherms models, and Cd(II) removal rate was as high as 56.9% in the simulated small intestine. In conclusion, DHPM shows great potential for enhancing the Cd(II) adsorption capacity by RBIDF. This research deals with the modification of RBIDF by DHPM treatments. The treatments at 120 or 150 MPa obviously increased Cd(II) adsorption capacity by unfolding the stiff structure to expose more oxygen-containing functional groups. DHPM is thus a safe and eco-friendly method to improve the physicochemical and adsorbent properties of RBIDF, which is a promising ingredient for use in food applications. • Dynamic high pressure microfluidization modified insoluble dietary fiber. • Modification increased the specific surface area and total negative charge. • Cd(II) adsorption capacity increased by 46% (pH 2) at 150 MPa. • Adsorption was well fitted by pseudo-second-order and Langmuir models. • Cd(II) removal rate was 56.9% in a simulated intestinal environment. [ABSTRACT FROM AUTHOR]

The objective of this study was to investigate the effect of particle size and microstructure on the physical and functional properties of soybean insoluble dietary fiber (IDF) in aqueous solution. Different IDF suspensions were obtained by ball milling (BM) and high-pressure homogenization (HPH) treatments. The results showed that the BM treatment significantly reduced the particle size distribution of the IDF, and the additional HPH treatment (BM-HPH) caused the IDF to become more porous, resulting in the formation of a honeycomb structure. Samples with a honeycomb network structure had higher hydration capacity and solubility. The water holding capacity, swelling capacity and solubility of I8 reached 18 g/g, 72 mL/g and 35%, respectively. I8 had the highest emulsifying stability and suspension stability. These results of the present study suggested that the reduction in particle size of IDF cannot fully account for its functional properties, of which the honeycomb structure played a more significant role. From the results of this study, it was clear that the functional properties of IDF depend on its small particle size and honeycomb structure. The present study indicated that a combination of BM and HPH treatments provides a new perspective for modifying and utilizing dietary fiber. [Display omitted] [ABSTRACT FROM AUTHOR]

• Carboxymethylation significantly improved the physicochemical properties of W-IDF. • The physicochemical and functional properties of E-IDF are better than W-IDF. • The antioxidant properties of the IDFs were improved by three kinds of modification methods. • Ultrafine comminution reduced the WRC and ORC, while increased WSC, CEC, GAC, and NIAC of W-IDF. To improve the industrial application of wheat bran insoluble dietary fiber (W-IDF), three modification methods (carboxymethylation, complex enzymatic hydrolysis, and ultrafine comminution) were compared on the basis of structural, physicochemical, functional, and antioxidant properties of W-IDF. FT-IR, DSC and SEM analysis showed that modifications contributed to alteration in morphology and arrangement of chemical bonds in W-IDF. Carboxymethylation effectively improved the water retention (WRC), water swelling (WSC), and glucose adsorption capacities (GAC); complex enzymatic hydrolysis greatly improved the oil retention (ORC), GAC, and nitrite ion adsorption capacities (NIAC). Although ultrafine comminution reduced the WRC and ORC, while positively influenced the GAC and NIAC. Moreover, total phenol content, total antioxidant capacity, DPPH radical scavenging capacity, Fe2+ chelating capacity and total reducing power were improved in modified W-IDF. Our results confirmed that carboxymethylation can improve the nutritive quality and sensory properties of W-IDF (nutritive ingredient) in food products. [ABSTRACT FROM AUTHOR]