Modification of bamboo shoot dietary fiber by extrusion-cellulase technology and its properties

Structure, thermal stability, physicochemical and functional characteristics of insoluble dietary fiber obtained from rice bran with steam explosion treatment: Effect of different steam pressure and particle size of rice bran

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.

Physicochemical and functional properties of carboxymethylated insoluble dietary fiber of Lycium barbarum seed dreg

Lycium barbarum seed dregs (LBSDs) were used for carboxymethyl modification, resulting in three degree of substitution samples (DS). Based on the substitution degree, samples were designated as low degree of substitution insoluble dietary fiber (L-IDF), medium degree of substitution insoluble dietary fiber (M-IDF) and high degree of substitution insoluble dietary fiber (H-IDF). Physicochemical and functional properties of IDFs were examined in relation to carboxymethylation degree. Infrared Fourier transform spectroscopy (FT-IR) confirmed the carboxymethyl group. According to the results, IDF, L-IDF, M-IDF, and H-IDF acquired higher enthalpy changes, and their thermal stability improved significantly. A higher DS resulted in an increase in hydration properties such as water retention capacity and water swelling capacity, as well as functional properties such as glucose adsorption capacity, nitrite ion adsorption capacity, and cholesterol adsorption capacity. As a result, carboxymethylation could effectively enhance the biological properties of L. barbarum seed dreg insoluble dietary fiber (LBSDIDF).

Effect of physical treatments on the functional and structural features of soluble dietary fiber from soybean dregs

BACKGROUND

In this research, the effects caused by ultrafine grinding (U), high-temperature cooking (HTC), microwave (M) and combined treatment (U-HTC, U-M) were evaluated on the functional properties and structural characteristics of soluble dietary fiber (SDF) obtained from soybean dregs.

RESULTS

Physical treatments could increase the extraction yield of SDF and improve the functional properties of SDF. The highest extraction yield (277.15 ± 5.87 g kg-1 based on the weight of soybean dregs) and purity (863.37 ± 5.15 g kg-1 based on the extract weight) of SDF was found in the sample by U-M treatment. U-HTC and U-M combined treatments significantly improved the water solubility and oil holding capacity of SDF. U-M treatment significantly increased the ability of SDF to adsorb cholesterol and perform cationic exchange; compared to the control, these abilities were increased by 138.46% and 10.38%, respectively. At pH 2.0, the nitrite ion adsorption capacity (NIAC) of SDF obtained by U-M combined treatment was 184.55 μg g-1 , which was significantly higher by 32.10% compared with that of the control. The results obtained by X-ray diffraction and scanning electron microscopy showed that the structure of SDF generated from soybean dregs became coarser and more porous, and the crystallinity decreased after physical treatments.

CONCLUSION

Combined physical treatment is an effective way to improve the extracted yield and functional properties of SDF from soybean dregs. © 2023 Society of Chemical Industry.

Optimization of Chemical Extraction Conditions of Dietary Fiber from Cistanche deserticola Residues and Its Structural Characteristics and Physicochemical and Functional Properties

Cistanche deserticola residues are by-products of the industrial production of Cistanche deserticola, which are currently often discarded, resulting in the waste of resources. In order to achieve the efficient utilization of Cistanche deserticola, dietary fiber from Cistanche deserticola residues was extracted chemically and the optimization of the extraction conditions was performed, using the response surface methodology to study the effects of the NaOH concentration, extraction temperature, extraction time, and solid-liquid ratio on the yield of water-soluble dietary fiber (SDF). The structural, physicochemical, and functional properties of the dietary fiber were also investigated. The results showed that the optimal conditions were as follows: NaOH concentration of 3.7%, extraction temperature of 71.7 °C, extraction time of 89.5 min, and solid-liquid ratio of 1:34. The average yield of SDF was 19.56%, which was close to the predicted value of 19.66%. The two dietary fiber types had typical polysaccharide absorption peaks and typical type I cellulose crystal structures, and the surface microstructures of the two dietary fiber types were different, with the surface of SDF being looser and more porous. Both dietary fiber types had good functional properties, with SDF having the strongest water-holding capacity and the strongest adsorption capacity for nitrite, cholesterol, sodium cholate, and glucose, while IDF had a better oil-holding capacity. These results suggest that Cistanche deserticola residues are a good source of dietary fiber and have promising applications in the functional food processing industry.

Polysaccharide-based biosorbents for cholesterol and bile salts in gastric-intestinal passage: Advances and future trends

Cholesterol is one of the hazard elements for many cardiovascular diseases, but many cholesterol-lowering drugs are expensive and unhealthy. Therefore, it is necessary to develop edible and safe biosorbents to reduce excess cholesterol and bile salts in the gastric-intestinal passage. Polysaccharide-based biosorbents offer a feasible strategy for decreasing them. This review summarized polysaccharide-based biosorbents that have been developed for adsorbing cholesterol and bile salts from the gastric-intestinal passage and analyzed common modification methods for these adsorbents. Finally, the adsorption models were also elucidated. Polysaccharides, including β-cyclodextrin, pectin, chitin/chitosan, dietary fiber extract, and cellulose, have been proposed for adsorbing cholesterol and bile salts in the gastric-intestinal passage as biosorbents. This is mainly due to the retention of pores, the capture of the viscosity network, and the help of hydrophobic interactions. In spite of this, the adsorption capacity of polysaccharides is still limited. Therefore, the modifications for them became the most popular areas in the recent studies of in vitro cholesterol adsorption. Chemical approaches namely grafting, (1) acetylation, (2) hydroxypropylation, (3) carboxymethylation, and (4) amination are considered to modify the polysaccharides for higher adsorption ability. Moreover, ultrasonic/microwave/pressure treatment and micron technology (microfluidization, micronization, and ball milling) are effective physical modification methods, while the biological approach mainly refers to enzymatic hydrolysis and microbial fermentation. The adsorption models are generally explained by two adsorption isotherms and two adsorption kinetics. In sum, it is reckoned that further food applications will follow soon.

A review on the hydration properties of dietary fibers derived from food waste and their interactions with other ingredients: opportunities and challenges for their application in the food industry

Dietary fiber (DF) significantly affects the quality attributes of food matrices. Depending on its chemical composition, molecular structure, and degree of hydration, the behavior of DF may differ. Numerous reports confirm that incorporating DF derived from food waste into food products has significant effects on textural, sensory, rheological, and antimicrobial properties. Additionally, the characteristics of DF, modification techniques (chemical, enzymatic, mechanical, thermal), and processing conditions (temperature, pH, ionic strength), as well as the presence of other components, can profoundly affect the functionalities of DF. This review aims to describe the interactions between DF and water, focusing on the effects of free water, freezing-bound water, and unfreezing-bound water on the hydration capacity of both soluble and insoluble DF. The review also explores how the structural, functional, and environmental properties of DF contribute to its hydration capacity. It becomes evident that the interactions between DF and water, and their effects on the rheological properties of food matrices, are complex and multifaceted subjects, offering both opportunities and challenges for further exploration. Utilizing DF extracted from food waste exhibits promise as a sustainable and viable strategy for the food industry to create nutritious and high-value-added products, while concurrently reducing reliance on primary virgin resources.

Valorization of Fibrous Plant-Based Food Waste as Biosorbents for Remediation of Heavy Metals from Wastewater-A Review

Mobilization of heavy metals in the environment has been a matter of concern for several decades due to their toxicity for humans, environments, and other living organisms. In recent years, use of inexpensive and abundantly available biosorbents generated from fibrous plant-based food-waste materials to remove heavy metals has garnered considerable research attention. The aim of this review is to investigate the applicability of using fibrous plant-based food waste, which comprises different components such as pectin, hemicellulose, cellulose, and lignin, to remove heavy metals from wastewater. This contribution confirms that plant-fiber-based food waste has the potential to bind heavy metals from wastewater and aqueous solutions. The binding capacities of these biosorbents vary depending on the source, chemical structure, type of metal, modification technology applied, and process conditions used to improve functionalities. This review concludes with a discussion of arguments and prospects, as well as future research directions, to support valorization of fibrous plant-based food waste as an efficient and promising strategy for water purification.

Effects of cavitation-jet technology combined with enzyme treatment on the structure properties and functional properties of OKARA insoluble dietary fiber

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.

Effect of alkaline hydrogen peroxide assisted with two modification methods on the physicochemical, structural and functional properties of bagasse insoluble dietary fiber

Bagasse is one of major by-product of sugar mills, but its utilization is limited by the high concentration of lignin. In this study, the optimal alkaline hydrogen peroxide (AHP) treatment conditions were determined by the response surface optimization method. The results showed that the lignin removal rate was 62.23% and the solid recovery rate was 53.76% when bagasse was prepared under optimal conditions (1.2% H₂O₂, 0.9% NaOH, and 46°C for 12.3 h), while higher purity of bagasse insoluble dietary fiber (BIDF) was obtained. To further investigate the modification effect, AHP assisted with high-temperature-pressure cooking (A-H) and enzymatic hydrolysis (A-E) were used to modify bagasse, respectively. The results showed that the water holding capacity (WHC), oil holding capacity (OHC), bile salt adsorption capacity (BSAC), and nitrite ion adsorption capacity (NIAC) were significantly improved after A-H treatment. With the A-E treatment, cation exchange capacity (CEC) and BSAC were significantly increased, while WHC, OHC, and glucose adsorption capacity (GAC) were decreased. Especially, the highest WHC, OHC, BSAC and NIAC were gained by A-H treatment compared to the A-E treatment. These changes in the physicochemical and functional properties of bagasse fiber were in agreement with the microscopic surface wrinkles and pore structure, crystallinity and functional groups. In summary, the A-H modification can effectively improve the functional properties of bagasse fiber, which potentially can be applied further in the food industry.

Properties of plant-derived soluble dietary fibers for fiber-enriched foods: A comparative evaluation

Plant-derived soluble dietary fibers (SDF) have many important physiological functions and the applications of SDF vary based on their properties, which are worth further investigating for fiber-enriched food production. In this study, SDF derived from konjac, apple, chicory, flaxseed, orange, psyllium seed, soybean and oat were purified, and their structural, physicochemical and functional properties were systematically evaluated. Monosaccharide composition analysis showed that these SDF belonged to heteropolysaccharides, of which konjac, psyllium seed, apple, soybean and oat SDF were glucomannan, arabinoxylan, pectin, arabinogalactan and glucan, respectively. The molecular weight of konjac glucomannan (KGM, 5.22 × 10⁶ Da) was the highest, and inulin, soybean arabinogalactan (SA) and oat glucan (OG) had higher water solubility. Moreover, KGM, apple pectin (AP), flaxseed SDF (FS) and psyllium seed arabinoxylan (PA) exhibited better water-holding capacity, swelling capacity, emulsifying activity and stability. Rheological studies and texture profile analysis suggested that KGM had the best viscosity and gelation ability. In addition, AP and orange SDF (OS) showed better α-amylase inhibitory activity, while OS and KGM had higher pancreatic lipase inhibitory activity. Also, KGM and FS displayed fine cholesterol absorption capacity. To summary, these functional properties illustrated the feasibility of SDF to regulate blood sugar and blood lipid levels.

Modification of Dietary Fibers to Valorize the By-Products of Cereal, Fruit and Vegetable Industry-A Review on Treatment Methods

Many by-products originating from cereal, fruit and vegetable industries contain quite high amounts of dietary fiber (DF), which play an important role in maintaining the healthy state of the human body. Nevertheless, huge proportions of these by-products are still underutilized as feed ingredients, to generate energy within an anaerobic digestion plant or even landfilled. One of the biggest hindrances in the valorization of such by-products is their very low soluble dietary fiber (SDF) to insoluble dietary fiber (IDF) ratios, impairing their nutritional functionality, palatability and technological applicability. Therefore, it is of interest to develop methods that can enhance the SDF to IDF ratio and that can be applied to the by-product streams of the food industry, enabling better valorization perspectives for human nutrition purposes. In this regard, the review paper provides an overview of existing technologies to modify the SDF to IDF ratio in by-products of the food industry by means of physical, chemical and biological treatments. For each type of treatment, available data on application examples including achieved increases in SDF contents are given. Additionally, a comparative discussion regarding the advantages and disadvantages of these methods is provided.

Positive effects of dietary fiber from sweet potato [Ipomoea batatas (L.) Lam.] peels by different extraction methods on human fecal microbiota in vitro fermentation

The purpose of this study was to compare the effects of sweet potato peels dietary fiber obtained by different extraction methods on intestinal health. Specifically, four different dietary fibers were extracted by hot water, microwave, ultrasonic and subcritical water methods. And the prebiotics effects of sweet potato peels dietary fibers were explored in an in vitro fermentation model, by determining intestinal gas content, short-chain fatty acid content, pH, ammonia content and the gut microbiota composition. The results showed that dietary fiber obtained by four different extraction methods could be utilized by GM and improve human health by increasing the abundance of beneficial bacteria (e.g., Bifidobacterium, Faecalibacterium, and Prevotella) and reducing the abundance of harmful bacteria (e.g., Proteobacteria, Romboutsia and Dorea), enhancing the relative abundance of SCFA-producing bacteria, promoting the production of short-chain fatty acids, reducing intestinal pH from 6.89 to 4.63 and ammonia. Among them, dietary fiber extracted by ultrasound is better than the other three extraction methods. This study suggests that all the four different extraction methods are available for sweet potato peels dietary fiber, and the extracted dietary fiber could be served as potential functional foods with great development value. In addition, it is beneficial to reduce the environmental pollution of sweet potato peels and improve the high-value processing and utilization of sweet potato by-products.

Comparison of different extraction methods on the physicochemical, structural properties, and in vitro hypoglycemic activity of bamboo shoot dietary fibers

The effect of alkali extraction (AE), enzymatic extraction (EE), ultrasonic-assisted enzymatic extraction (UAEE), and shear homogeneous-assisted enzymatic extraction (SHAEE) on the physicochemical, structural properties, and in vitro hypoglycemic activity of bamboo shoot dietary fibers (BSDF) were investigated and compared. BSDF obtained by AE had the lowest protein content and crystallinity index. The lowest oil holding capacity (OHC) and highest protein content were observed in EE. BSDF generated highest OHC and glucose adsorption capacity by UAEE. SHAEE obtained the highest SDF content (17.89%), water-holding capacity (8.81 g/g), and α-amylase activity inhibition ratio (19.89%) and the smallest particle size (351.33 μm). BSDF extracted by SHAEE and UAEE presented a porous and loose structure. Furthermore, the in vitro hypoglycemic activity of the four BSDF samples generally followed the order of SHAEE > UAEE > EE > AE. Results show that SHAEE is an innovative and promising method to obtain BSDF with its excellent physicochemical and functional properties.

Feasibility of pomelo peel dietary fiber as natural functional emulsifier for preparation of Pickering-type emulsion

BACKGROUND

The application of Pickering emulsions stabilized by food-derived particles is of great interest, studies have focused on development of natural functional emulsifiers from agricultural byproducts. Dietary fiber (DF) has been recognizing for its excellent physiological functions. Moreover, physicochemical properties of pomelo peel DF (PDF) make it a potential emulsifier. However, pristine PDF is not suitable as emulsifier due to its compact physical structure and high hydrophobicity, which seriously limits its utilization. The objective of the study was to investigate the effects of cellulase on physicochemical properties of PDF and to illustrate the feasibility of cellulase modified PDF (MPDF) as natural functional emulsifier.

RESULTS

Cellulase modification significantly improved (P < 0.05) specific surface area, water-holding capacity/oil-holding capacity, viscoelasticity, hydrophobicity, and pore structure while decreased crystallinity index and particle size of PDF. Emulsion could remain stable over 30 days as MPDF concentrations up to 1 wt% and oil/water ratio 3:7. The appearance stability of emulsions was not influenced by temperature (4-60 °C), pH (3.0-12.0), and ion concentration (0-200 mmol L^-1 ) which was similar to Pickering emulsions. The mechanism of MPDF as an emulsifier was mainly attributed to the combination of Pickering effect and the three-dimensional network. In addition, MPDF showed higher antioxidant capacity in emulsions than other classical emulsifiers.

CONCLUSION

The results illustrated that MPDF has a favorable feasibility for preparation of stable Pickering-type emulsions, which will be a practical support for application of PDF as a natural functional emulsifier and will be helpful to realize the resource utilization of DF in pomelo industries. © 2022 Society of Chemical Industry.

The Influence of Different Extraction Methods on the Structure, Rheological, Thermal and Functional Properties of Soluble Dietary Fiber from Sanchi (Panax notoginseng) Flower

The influence of different extraction methods, such as acidic (AC), enzymatic (EN), homogenization (H), ultrsonication (U) and alkali (AL), on structure, rheological, thermal and functional properties of soluble dietary fiber (SDF) from Sanchi flower was evaluated in this study. The highest extraction yield (23.14%) was obtained for AL-SDF extract. Glucose (Glc) and galactose (Gal) were found to be the major constituents in Sanchi SDF. Homogenization and Ultrsonication treatments caused significant compaction of pores in the microstructures. FTIR analysis showed increased hydrolysis of pectin and hemicellulose in U, AL and AC-SDF extracts. H-SDF and AC-SDF exhibited similar shear rate change with the rise in shear stress. H-SDF was thermally more stable than other SDF extracts. Among all extraction methods, H-SDF and U-SDF exhibited the highest water holding capacity (WHC), oil-holding capacity (OHC), Bile acid-adsorption capacity (BAC), Cholesterol-adsorption capacity (CAC) and Glucose adsorption capacity (GAC). Thus, Sanchi flower SDF with improved functional properties could be utilized as a functional food ingredient in the development of various food products.

Efficiency Assessment of Bacterial Cellulose on Lowering Lipid Levels In Vitro and Improving Lipid Metabolism In Vivo

Bacterial cellulose (BC) is well known as a high-performance dietary fiber. This study investigates the adsorption capacity of BC for cholesterol, sodium cholate, unsaturated oil, and heavy metal ions in vitro. Further, a hyperlipidemia mouse model was constructed to investigate the effects of BC on lipid metabolism, antioxidant levels, and intestinal microflora. The results showed that the maximum adsorption capacities of BC for cholesterol, sodium cholate, Pb²⁺ and Cr⁶⁺ were 11.910, 16.149, 238.337, 1.525 and 1.809 mg/g, respectively. Additionally, BC reduced the blood lipid levels, regulated the peroxide levels, and ameliorated the liver injury in hyperlipidemia mice. Analysis of the intestinal flora revealed that BC improved the bacterial community of intestinal microflora in hyperlipidemia mice. It was found that the abundance of Bacteroidetes was increased, while the abundance of Firmicutes and Proteobacteria was decreased at the phylum level. In addition, increased abundance of Lactobacillus and decreased abundance of Lachnospiraceae and Prevotellaceae were obtained at the genus level. These changes were supposed to be beneficial to the activities of intestinal microflora. To conclude, the findings prove the role of BC in improving lipid metabolism in hyperlipidemia mice and provide a theoretical basis for the utilization of BC in functional food.

Dietary Fiber in Plant Cell Walls—The Healthy Carbohydrates

Dietary fiber (DF) is one of the major classes of nutrients for humans. It is widely distributed in the edible parts of natural plants, with the cell wall being the main DF-containing structure. The DF content varies significantly in different plant species and organs, and the processing procedure can have a dramatic effect on the DF composition of plant-based foods. Given the considerable nutritional value of DF, a deeper understanding of DF in food plants, including its composition and biosynthesis, is fundamental to the establishment of a daily intake reference of DF and is also critical to molecular breeding programs for modifying DF content. In the past decades, plant cell wall biology has seen dramatic progress, and such knowledge is of great potential to be translated into DF-related food science research and may provide future research directions for improving the health benefits of food crops. In this review, to spark interdisciplinary discussions between food science researchers and plant cell wall biologists, we focus on a specific category of DF—cell wall carbohydrates. We first summarize the content and composition of carbohydrate DF in various plant-based foods, and then discuss the structure and biosynthesis mechanism of each carbohydrate DF category, in particular the respective biosynthetic enzymes. Health impacts of DF are highlighted, and finally, future directions of DF research are also briefly outlined.

Gut modulation based anti-diabetic effects of carboxymethylated wheat bran dietary fiber in high-fat diet/streptozotocin-induced diabetic mice and their potential mechanisms

We explored the effect of carboxymethylated wheat bran dietary fibers (DFs) on mice with type 2 diabetes (T2D) (induced by HFD combined with STZ) and their possible hypoglycemic mechanism. After feeding the diabetic mice with modified DFs for four weeks, the DFs had lipid lowering and anti-hyperglycemic effect, via increasing the levels of insulin, GLP-1, PYY, and SCFAs in diabetic mice, and improving the histopathology of liver and pancreas. qRT-PCR results showed that the intake of DFs up-regulated the expression levels of G6Pase and Prkce, and down regulated the expression levels of Glut2 and InsR in the liver of diabetic mice. It is suggested that DFs may play a role by inhibiting 1,2-DAG-PKCε pathway, improving insulin receptor activity and insulin signal transduction. 16 S rDNA high-throughput sequencing results showed that the DFs significantly improved the relative abundance of Akkermansia muciniphila, increased the diversity of gut microbiota and reduced the ratio of Firmicutes to Bacteroidetes, thus promoting the hypoglycemic and hypolipidemic effect on diabetic mice. Our study can foster the further understanding of the gut modulatory biomarkers and related metabolites, and may extend the basis for DFs as a potential dietary intervention to prevent or treat the T2D.

Effects of carboxymethylation, hydroxypropylation and dual enzyme hydrolysis combination with heating on physicochemical and functional properties and antioxidant activity of coconut cake dietary fibre

The effects of carboxymethylation, hydroxypropylation and dual enzyme hydrolysis combined with heating on some physicochemical and functional properties, and antioxidant activity of coconut cake dietary fibre (CCDF) were studied. Results showed that both the hydroxypropylation and carboxymethylation could effectively improve (p < 0.05) the water retention capacity (WRC), oil retention capacity (ORC), viscosity, α-amylase inhibition activity (α-AAIR), glucose dialysis retardation index (GDRI), cation-exchange capacity, emulsifying capacity index (ECI) and bile adsorption capacity (BAC) of CCDF. Moreover, the cellulase and hemicellulase hydrolysis combination with heating significantly enhanced (p < 0.05) the soluble dietary fibre content, WRC, emulsion stability, GDRI, α-AAIR and BAC of CCDF; but caused decrease in ORC and browning of color. In addition, improvement of total phenol content, Fe²⁺ chelating ability, ABTS⁺· and O₂^-· scavenging activity were obtained in carboxymethylaticted CCDF. These effects were mainly attributed to the composition and structural modifications as evident from SEM, FT-IR and XRD analysis.

Modification of wheat bran insoluble dietary fiber with carboxymethylation, complex enzymatic hydrolysis and ultrafine comminution

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.