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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]

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]

• 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]

[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]

• 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]

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]

[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] • 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]

[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]

• 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]