Microwave assisted extraction with three modifications on structural and functional properties of soluble dietary fibers from grapefruit peel

Modification of black soybean (Glycine max(L.)merr.) residue insoluble dietary fiber with ultrasonic, microwave, high temperature and high-pressure, and extrusion

Recent studies have emphasized the modification of Insoluble Dietary Fiber (IDF) to enhance its physicochemical properties and functional performance. This study systematically examined the effects of ultrasonic treatment, microwave irradiation, high-temperature and high-pressure processing, and screw extrusion on the physicochemical characteristics, in vitro antioxidant activity, and adsorption capacities of High-Purity Insoluble Dietary Fiber (HPIDF) derived from black bean residues. Although these physical modifications did not alter the functional group composition or crystalline structure of HPIDF, they significantly enhanced its porosity, water-holding capacity (WHC), oil-holding capacity (OHC), and adsorption capacities for glucose, cholesterol, bile salts, and metal ions. Notably, HPIDF treated under high-temperature and high-pressure conditions exhibited the highest adsorption capacities: 9.86 mmol/g for glucose, 8.69 mg/g (pH 2) and 9.69 mg/g (pH 7) for cholesterol, 0.183 g/g (pH 2) and 0.127 g/g (pH 7) for sodium cholate, and 0.699 mg/g (pH 2) and 0.774 mg/g (pH 7) for Cr2+.

Development of supercritical technology to obtain improved functional dietary fiber for the valorization of broccoli by-product

BACKGROUND

This research aimed to enhance the functional value of dietary fiber from broccoli leaves using supercritical fluid technology. By optimizing pressure, temperature, and time parameters through response surface methodology, the study sought to improve the bioactive properties of the fiber and develop a predictive model for its chemical composition and functional properties.

RESULTS

Structural analysis indicated that modified samples had a higher concentration of oligosaccharides than control samples did, with significant increases in galacturonic acid and neutral sugars after supercritical fluid technology treatment, highlighting enhanced pectin release due to cell wall degradation. Functional properties, such as water solubility, glucose absorption capacity, and antioxidant activity, improved significantly under optimized conditions (191 bar, 40 °C, 1 h). Multivariate analysis confirmed the effectiveness of supercritical fluid technology in enhancing the dietary fiber properties, achieving a global desirability value of 0.805.

CONCLUSION

These results underscore the potential of supercritical technology for valorizing broccoli leaf by-products, enhancing their health-promoting characteristics and functional applications in the food industry. © 2024 The Author(s). Journal of the Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Study on the structure and adsorption characteristics of the complex of modified Lentinus edodes stalks dietary fiber and tea polyphenol

The waste Lentinus edodes stalks from Lentinus edodes processing were used as raw materials by the steam explosion to prepare modified Lentinus edodes stalks dietary fiber and combined with tea polyphenols to form the SE-DF-tea polyphenols complex (SE-DF-TPC). The SE-DF-tea polyphenols mixture (SE-DF-TPM) was prepared according to the complex's optimal adsorption conditions. Fluorescence microscopy, Fourier transform infrared spectroscopy, particle size measurement, thermogravimetric analysis, and X-ray diffraction were used to analyze its structure, and the thermal stability of the complex and its adsorption capacity for lipids, cholesterol, and cholates were studied. The results indicate that dietary fiber from modified Lentinus edodes stalks and tea polyphenols form a stable complex through non-covalent bonding. In addition, the thermal stability of the phenolic substances in the complex and the adsorption capacity of the complex to fats, cholesterol, and cholates is better than modified dietary fiber and the mixture of dietary fiber and tea polyphenols.

Effect of different pretreatment methods on soluble dietary fiber macromolecules extracted from Korla fragrant pear (Pyrus sinkiangensis Yü): Structure, physicochemical properties, and biological activity

Herein, Korla fragrant pear (KFP) was subjected to ultrasonication (UA), microwave (MA), high-pressure humid heat (HPHH), and composite enzyme hydrolysis (CEH) pretreatments before the extraction of soluble dietary fiber. The yield, structural characteristics, and functional properties of SDF obtained after the different pretreatments were compared. All the aforementioned pretreatment methods increased the yield of SDF and decreased that of insoluble dietary fiber. The highest yield of SDF was obtained after the HPHH pretreatment (10.11 %). The SDF obtained after pretreatment exhibited loose, cracked, and porous structures, decreased crystallinity and molecular weight (Mw), and improved physicochemical and functional properties. The highest water solubility (72.35 %), cation exchange capacity (0.92 mmoL/g), glucose adsorption capacity (7.80 mmoL/g), and cholesterol adsorption capacity (11.95 and 16.59 mg/g at pH 2 and 7, respectively), in vitro antioxidant activity, and α-glucosidase inhibitory activity were achieved following the CEH pretreatment. Multivariate analysis revealed that most of the functional properties were negatively correlated with the crystallinity and Mw of SDF but positively correlated with the antioxidant activities (e.g., DPPH and ABTS) and α-glucosidase inhibitory activity. These findings provide a theoretical basis for the extraction, modification, and application of SDF extracted from KFP.

Production, structural and functional properties of dietary fiber from prosomillet bran obtained through Bifidobacterium fermentation

The effects of Bifidobacterium fermentation on dietary fiber (DF) of prosomillet bran were studied. Firstly, optimal fermentation conditions for extracting soluble dietary fiber were determined through single factor tests and orthogonal experiments. The structural features were evaluated by means of scanning electron microscopy, X-ray diffraction, Fourier infrared spectroscopy, particle size analysis, thermogravimetric analysis, and monosaccharide content. The results showed that some the crystal structure changed from crystal to non-crystal, which was followed by the decrease of thermal stability. The DF's surface loosened and its particle size decreased after fermentation. Meanwhile, DF showed similar spectral characteristics before and after fermentation, but the monosaccharide composition changed. Furthermore, the physicochemical properties were investigated. The fermented DF exhibited higher water swelling capacity, water holding capacity, oil holding capacity. Finally, improvements in glucose adsorption capacity, cation exchange and antioxidant properties were observed. These results indicated that Bifidobacteria fermentation is beneficial to the modification of DF.

Insights into the relationship between the acetylation of Dendrobium officinale polysaccharides and the ability to promote sIgA secretion

The acetyl group is a significant reactive component of Dendrobium officinale polysaccharide (DOP). In this study, we prepared DOPs with different degrees of acetyl substitution and investigated how the acetyl group, a naturally occurring characteristic of DOP, influences the immunomodulatory activity and the production of secretory IgA (sIgA) in the small intestine. Physical property measurements revealed significant changes in surface morphology and solubility of DOP caused by the addition or removal of acetyl groups. In vivo studies have demonstrated that DOP can mitigate Cyclophosphamide-induced immunosuppression by enhancing the immune organ index, promoting immunoglobulin secretion, and increasing the population of immune cells. Additionally, DOP can enhance sIgA production through multiple pathways, including enhanced IgA+ B cell class switch recombination, gut homing of IgA+ plasma cells, and upregulation of factors involved in sIgA composition and secretion. Correlation analysis revealed strong, piecewise-specific correlations between DOP acetylation and sIgA production at varying intervals of acetyl substitution. Based on this, we propose a theoretical framework in which the acetylation of DOP and the secretion of small intestinal sIgA demonstrate a "piecewise correlation". This framework illustrates the influence of DOP acetylation on immunomodulatory activity and provides a theoretical basis for enhancing the added value of Dendrobium officinale resources.

Effects of acid, alkaline and enzymatic extraction methods on functional, structural and antioxidant properties of dietary fiber fractions from quince (Cydonia oblonga Miller)

In this study, quince soluble dietary fiber (SDF) and insoluble dietary fiber (IDF) were obtained by acid extraction, enzyme extraction and alkaline extraction methods. The acid extracted DF displayed higher results compared to enzyme and alkaline extraction methods in terms of water holding capacity (15.97 g/g SDF), oil holding capacity (1.05 g/g SDF) and nitrite ion adsorption capacity (92.83 mg/g SDF). The antioxidant activity and phenolic content of acid extracted IDF were significantly higher than the other quince DFs. In addition, quince DFs exhibited in vitro hypoglycaemic activity, exhibiting high glucose adsorption capacity (237 mg/g) and α-amylase inhibition activity (82 %). Similarly, acid extracted SDF of quince showed in vitro hypolipidemic activity, with cholesterol adsorption capacity of 155 mg/g and lipase inhibition activity of 36 %. The structures and thermal properties of quince DFs were characterized by FT-IR and TGA. Quince DFs with high functional properties might be suitable agents for functional food formulations, such as meat products, low-calorie fruit bars, flour mixtures, etc.

Effects of ultrasonic treatment on the physicochemical, structural, and functional properties of soluble dietary fiber from coffee peels

Coffee peel (CP) is an important by-product of coffee processing which is rich in bioactive components. In the present work, we extracted coffee peel soluble dietary fiber (CSDF) via ultrasound-assisted alcohol precipitation to reduce resource waste as well as environmental pollution and evaluate its structure, monosaccharide composition, and functional and physicochemical characters. Based on our findings, ultrasonic treatment decreased particle size of CSDF from 131.49 ± 7.67 μm to 75.84 ± 1.20 μm, and markedly improved the homogeneity. The ultrasonic power of 200-300 W resulted in increased thermal stability due to a higher crystallinity of the CSDF. Increasing the ultrasonic power (0-500 W) reduced rhamnose level from 8.25 % to 7.61 % (p < 0.05) and the SDF treated with 100 W of ultrasonic power had the highest fructose content (21.37 %). The ultrasonic treatment improved the water-solubility, oil-holding capacities and water-holding capacities of CSDF, with highest water-holding capacity being obtained at 300 W (8.92 ± 1.57 g/g). Additionally, the glucose and nitrite ion adsorption capacities significantly improved after ultrasonic modification. These findings may expand the application of CSDF in the food industry.

Enhancing Rice Bran Soluble Dietary Fiber Yield Through Sequential Ultrasound-Xylanase Treatment

The main aim of this study was to enhance the content of soluble dietary fiber (SDF) derived from rice bran (RB) through various treatments, including physical methods (ultrasound and alternating magnetic field (AMF)) and enzymatic approaches (cellulase and xylanase), applied individually or in combination. The results revealed that AMF treatment was the most effective single modification technique for increasing SDF yield, followed by treatments with xylanase, cellulase, and ultrasound. Notably, among the combined approaches, the sequential ultrasound-xylanase treatment (U-X) demonstrated the highest potential for enhancing SDF yield. Further optimization experiments revealed that under the conditions of a xylanase addition of 4.3 mg/g sample, a material-to-liquid ratio of 50 mL/g, and an ultrasonic power of 72 W, the yield of U-X-SDF significantly increased from 1.03% to 18.4%. Compared to unmodified samples, the modified SDF groups exhibited marked enhancements in water holding capacity (42.5-86.4%) and water solubility (21.0-30.6%), while the unmodified SDF displayed superior oil holding capacity than the modified groups. In summary, the sequential ultrasound-xylanase treatment not only improves the SDF yield but also enhances the functional properties of RB-derived SDF, positioning it as a valuable health-promoting food additive with potential benefits for both laboratory and industrial food applications. The optimized treatment process can contribute to the development of new functional food ingredients from RB, thereby promoting health and wellness in consumers.

Structural Characterization of, and Protective Effects Against, CoCl2-Induced Hypoxia Injury to a Novel Neutral Polysaccharide from Lycium barbarum L

Oxidative stress is closely related to the occurrence and development of ischaemic stroke. Natural plant polysaccharides have potential value in inhibiting oxidative stress and preventing ischaemic stroke. Here, a novel neutral polysaccharide named LICP009-3F-1a with a Mw of 10,780 Da was separated and purified from Lycium barbarum L. fruits. Linkage and NMR data revealed that LICP009-3F-1a has the following backbone: →4)-β-D-Glcp-(1→6)-β-D-Galp-(1→, with a branched chain of β-D-Galp-(1→3)-β-D-Galp-(1→, α-L-Araf-(1→ and →6)-α-D-Glcp-(1→ connected to the main chain through O-3 of →3,6)-β-D-Galp-(1→. X-ray and SEM analyses showed that LICP009-3F-1a has a semicrystalline structure with a laminar morphology. Thermal property analysis showed that LICP009-3F-1a is thermally stable. In vivo experiments suggested that LICP009-3F-1a could inhibit hypoxia-induced oxidative stress damage by eliminating ROS, reversing and restoring the activities of the antioxidant enzymes SOD, CAT, and GPx, and reducing the expression levels of the HIF-1α and VEGF genes. Blocking the apoptosis genes Bax and Caspase 3 and upregulating the expression of the antiapoptotic gene Bcl-2 protected PC12 cells from hypoxia-induced apoptosis. These results suggest that LICP009-3F-1a may have multiple potential uses in the treatment of IS.

Mechanism of promoting okara insoluble to soluble dietary fiber by high-pressure homogenization-microbial fermentation

This study investigated the conversion of okara insoluble dietary fiber (IDF) to soluble dietary fiber (SDF) using high-pressure homogenization (HPH) combined with microbial fermentation. The conversion mechanism was analyzed from four aspects: correlation, proteomics, component and structure under. Results indicated a negative correlation between pH and SDF yield (r = -0.9885, p < 0.05), while cellulase and xylanase showed a positive correlation with SDF yield (p < 0.05). Proteomic analysis identified 22 key enzymes involved in IDF degradation. According to the composition and structure, the combined treatment effectively reduced the aggregation of IDF, promoting its transformation into SDF. HPH treatment primarily acted on the hemicellulose fractions in the amorphous region, while microbial fermentation broke hydrogen bonds between hydroxyl groups in the crystalline regions of cellulose, enhancing the conversion of more exposed cellulose. This study provided theoretical support for the development and utilization of okara IDF.

Machine learning-enhanced modeling and characterization for optimizing dietary Fiber production from Highland barley bran

This study investigated the modification of highland barley bran through co-fermentation of Lactobacillus bulgaricus and Kluyveromyces marxianus, and developed a dynamic prediction model for DF content under these co-fermentation conditions using machine learning algorithms. The results showed that the XGBoost algorithm could predict changes in the DF component content (R2 = 0.9553(SDF/IDF), RMSE = 0.0464.) and identify optimal fermentation conditions. Under these optimal conditions, both strains exhibited synergistic effects, where the lactic acid produced by Lactobacillus bulgaricus and β-glucosidase produced by Kluyveromyces marxianus may facilitate IDF decomposition and conversion, resulting in a maximum SDF/IDF ratio of 0.6911. This led to a 27.65 % reduction in IDF content and a 19.11 % increase in SDF content. Moreover, the physicochemical and functional properties of DF were enhanced after co-fermentation. The structure of DF became looser and more porous, its thermal stability improved, and its water-holding, oil-holding, and swelling capacities increased by 53.54 %, 16.11 %, and 44.96 %, respectively, compared with the unfermented counterpart; in terms of adsorption characteristics, its glucose, cholesterol and nitrite adsorption capacities were also significantly improved. According to in vitro gastrointestinal simulated digestion, digestion would have a great impact on the fermented DF, which showed good antioxidant properties during the intestinal digestion stage.

Advancements in modifying insoluble dietary fiber: Exploring the microstructure, physicochemical properties, biological activity, and applications in food industry-A review

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.

Ultra-high pressure assisted extraction of polysaccharide from Bangia fusco-purpurea: Structure and in vitro hypolipidemic activity

The structure and in vitro hypolipidemic activity of Bangia fusco-purpurea polysaccharide (BFP) assisted extracted with ultra-high pressure (UHP) at 100-600 MPa were studied. Compared to native BFP, UHP assisted extracted BFP had a more loose network structure with higher total sugar and uronic acid contents while less molecular weight (p < 0.05). Moreover, UHP assisted extraction significantly improved the in vitro hypolipidemic and antioxidant activity of BFP. Especially at 400 MPa UHP, the cholesterol adsorption and antioxidant capacities of BFP were increased by approximately 38.02 % and 11.69 %-32.29 %, respectively. BFP with UHP assisted extraction could alleviate oleic acid-induced lipid accumulation and lipid oxidation in HepG2 cells more effectively by activating the AMPK signaling pathway as well as inhibiting PPARγ expression, which was much related with its reduced molecular weight and loose network structure. The findings indicated that UHP assisted extracted BFP has better potential to develop natural hypolipidemic agent.

Influence of fermentation with lactic bacteria on the structure, functional properties and antioxidant activity of flaxseed gum

Flaxseed meal is a by-product of flaxseed oil extraction. In this research, lactic acid bacteria suitable for modification of flaxseed gum were screened based on cellulase activity and the extraction rate of flaxseed gum. The enzyme-weight method was employed to extract flaxseed gum (SDF). The influences of fermentation modification on the extraction yield, structure, function, and antioxidant activity of flaxseed gum was investigated. Based on the enzyme-producing activity and extraction rate, Lactobacillus plantarum (LP-3), Bacillus paracaetocasei (KLDS-82), and Lactobacillus acidophilus (LAC-11) were identified as the most suitable strains for modifying flaxseed gum. The results indicated that the extraction yield of flaxseed gum was 18.45 % ± 0.2 % after fermentation with KLDS-82, which was significantly higher than that of the unmodified group. After fermentation, the microstructure of flaxseed gum became looser and more porous. The characteristic absorption peak of polysaccharide was observed through scanning electron microscopy (SEM), Fourier transform infrared (FT-IR), and X-ray diffraction (XRD), and the crystallization area was reduced. Simultaneously, its swelling capacity, water-holding capacity, oil-holding capacity, and other physicochemical properties have also been enhanced. The glucose adsorption capacity, cholesterol adsorption capacity, sodium cholic acid adsorption capacity, cation exchange capacity, α-glucosidase inhibitory activity, and antioxidant properties of SDF modified by Bacillus paracaetocasei (F-SDF) were significantly higher than those of Lactobacillus acidophilus modified SDF (S-SDF), Lactobacillus plantarum modified SDF (Z-SDF), and unmodified SDF (U-SDF). In conclusion, the modification effect of KLDS-82 is the most remarkable. Therefore, it can be utilized as a functional raw material in food.

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.

Extraction of Soluble Dietary Fiber from Sunflower Receptacles (Helianthus annuus L.) and Its Alleviating Effect on Constipation in Mice

BACKGROUND/OBJECTIVES

Sunflower receptacles are the main by-product of the processing of Helianthus annuus L.

METHODS

In this study, several extraction methods of soluble dietary fiber (SDF) from sunflower receptacles were evaluated, and then, the physicochemical structure and functional properties of these SDFs were examined. Finally, a mouse constipation model was established to explore its therapeutic potential for constipation.

RESULTS

The results showed that the SDF yield of citric acid extraction and enzyme extraction was better than that of hot-water extraction. Structural characterization showed that the three SDF functional groups were similar and amorphous, while the surface distribution of the SDF obtained by the citric acid extraction method (ASDF) had more fine pores. Physicochemical analysis showed that ASDF had the best water-holding capacity, oil-holding capacity, and expansion force. Animal experiments showed that the first black stool defecation time of the model group changed significantly (p < 0.001), indicating that the model was successful. Compared with the model group, the middle- and high-dose groups reduced the first black stool defecation time (p < 0.05 or p < 0.01) and increased the fecal water content (p < 0.05). The high-dose group significantly promoted the intestinal peristalsis of mice (p < 0.05). From hematoxylin-eosin (H&E) staining, it can be seen that the three dose groups of ASDF can improve the damage of mouse colon tissue induced by loperamide hydrochloride to a certain extent.

CONCLUSIONS

Our results show that ASDF has good physical and chemical properties and laxative properties and has broad development space in the field of health food.

Extraction Method Effects on Structural Properties and Functional Characteristics of Dietary Fiber Extracted from Ginseng Residue

In this research, the dietary fibers (DFs) from ginseng residue were extracted by employing three different extraction methods (alkaline: AL, acidic: AC, enzymatic: EN). The extracted DFs were characterized in terms of their structural and functional properties. The results clearly showed that, regardless of the extraction methods, all DF samples exhibited representative infrared spectral features. The DF extracted by AC (citric acid) had more porous structures with a looser configuration, in conjunction with high apparent viscosity, whereas the DF extracted by EN (α-amylase and protease) exhibited higher thermal stability. Moreover, the monosaccharide composition of the DF samples was significantly influenced by the extraction method type. The DF from ginseng residue extracted by AC had the highest functional properties, such as water holding capacity (8.16 g/g), oil holding capacity (3.99 g/g), water swelling capacity (8.13 g/g), cholesterol-absorption capacity (12.85 mg/g), bile acid absorption capacity (91.51 mg/g), nitrite ion absorption capacity (124.38 ug/g at pH 2.0), glucose absorption capacity (52.67 mg/g at 150 mmol/L), as compared to those of DF extracted by the EN and AL (sodium hydroxide) methods. Hence, ginseng residue-derived DF extracted by the AC method may be potentially employed in the preparation of functional food ingredients.

Biovalorization of mango byproduct through enzymatic extraction of dietary fiber

Mango is considered one of the most important tropical fruits worldwide in terms of its consumption and consumer acceptability. Its processing generates huge quantities of mango byproducts, which is often discarded unscrupulously into the environment and, therefore, needs effective waste management practices. The extraction of mango peels' dietary fiber using enzymatic method can be a useful valorization strategy for management of mango by-products. In the present investigation, dietary fiber (soluble and insoluble fraction) was extracted by enzymatic hydrolysis using α-amylase, protease, and amyloglucosidase. Highest yield of dietary fiber (67.5%, w/w) was obtained at 60 °C temperature using recommended enzyme concentrations including α-amylase (40 µL), protease (110 µL), and amyloglucosidase (200 µL) after a treatment time of 60 min. SEM analysis indicated the increased porosity of dietary fiber samples caused due to the hydrolytic effect of enzymes on its surface structure, whereas FTIR analysis confirmed the functional groups present in dietary fiber. The coexistence of crystalline and amorphous nature of polymers present in soluble and insoluble fractions of dietary fiber was assessed by XRD analysis. Further, the analysis of functional properties including WHC, OHC, and SC revealed the suitability of using extracted mango peel's dietary fiber in the food systems.

Comparative study on physicochemical properties and hypoglycemic activities of intracellular and extracellular polysaccharides from submerged fermentation of Morchella esculenta

The structural characteristic, physicochemical properties and structure-hypoglycemic activity relationship of intracellular (IPS) and extracellular (EPS) from submerged fermentation of Morchella esculenta were systematically compared and assessed. Both IPS and EPS were neutral, with a triple-helical conformation, and composed of galactose, glucose and mannose monosaccharides in different molar ratios. The molecular weight and particle size of IPS were higher than those of EPS. FTIR and SEM showed that the main functional group absorption peak intensity, glycosidic bond type and surface morphology of the two polysaccharides differed. Analysis of rheological and thermal properties revealed that the viscosity of IPS was higher than that of EPS, while thermal stability of EPS was greater than that of IPS. Hypoglycemic activity analysis in vitro showed that both IPS and EPS were non-competitive inhibitors of α-amylase and α-glucosidase. EPS showed strong digestive enzyme inhibitory activity due to its higher sulphate content and molar ratio of galactose, lower Mw and particle size. Meanwhile, with its higher Mw and apparent viscosity, IPS showed stronger glucose adsorption capacity and glucose diffusion retardation. These results indicate that IPS and EPS differed considerably in structure and physicochemical properties, which ultimately led to differences in hypoglycemic activity. These results not only suggested that IPS and EPS has the potential to be functional foods or hypoglycemic drugs, but also provided a new target for the prevention and treatment of diabetes with natural polysaccharides.

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

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

The hypoglycemic effect of enzymatic modified dietary fiber from bamboo shoot on type 2 diabetes rats

Bamboo shoot is a healthy food rich in dietary fiber (DF). However, its highly insoluble DF and fibrous texture limit its application in industrially processed foods. To achieve industrial processing of bamboo shoot, cellulase was used to improve the physical characteristics of bamboo shoot DF in this study. After enzymatic hydrolysis, the content of soluble DF (SDF) of bamboo shoot increased by 99.28% (from 5.53% to 11.02%) significantly (p < 0.01). At the same time, the effect of enzymatic-modified bamboo SDF (EMBSDF) on streptozotocin-induced type 2 diabetes rats was explored. Results demonstrated that the high dose of EMBSDF (312.8 mg/kg) treated rats showed significant improvements in terms of glucose tolerance and insulin sensitivity (p < 0.01) compared with the diabetes rats. Meantime, it was observed that the levels of glucagon-like peptide-1, adiponectin and interleukin-4 of high dose of EMBSDF compared with diabetes rats were increased (p < 0.01) by 57.79%, 159.13%, and 6.17%, respectively. The tumor necrosis factor-α, C-reactive protein, and leptin levels were decreased (p < 0.01) by 62.89%, 31.53%, and 7.84%, respectively. Furthermore, apparent kidney and pancreas histology improvements were found in high-dose and mid-dose EMBSDF-treated diabetes rats. These results indicated that the modified DF significantly improved diabetes.

Complexation of Olive Protein with Soluble Dietary Fibers: A Way to Improve the Functional Properties of Proteins and Efficiently Utilize Olives

High-value resources beyond oil extraction for the olive industry need to be developed due to increased olive production. Soluble dietary fibers (SDFs) and olive proteins (OPIs) are important components of olives. However, the commercial production process partially damages OPIs' emulsifying and foaming properties. Thus, the preparation of SDF-OPI complexes would help protect and even improve the emulsifying and foaming properties. The effects of pH and thermal-ultrasonic treatment on the complexation were explored, which showed that the SDF-OPI complexes prepared at pH 5 exhibited superior solubility (p < 0.05). SDF addition noticeably improved OPI thermal stability, emulsifying properties, and foaming properties. Moreover, the complexes prepared by thermal-ultrasonic treatment exhibited higher emulsion stability and lower emulsification activity than those prepared without thermal-ultrasonic treatment. In the acidic system, the electrostatic interaction was considered the main driving factor, assisted by the hydrophobic interaction. Additionally, after thermal-ultrasonic treatment, the covalent binding was observed by infrared spectroscopy. These results revealed the interaction mechanism between SDF and OPI, and the complexes significantly enhanced the functional properties of OPI. This study provides a reference for the high-value utilization of olives, thus broadening their potential uses in the food sector and beyond.

Effects of Different Extraction Methods on the Structural and Functional Properties of Soluble Dietary Fibre from Sweet Potatoes

In this study, hot water treatment (WT), ultrasonic treatment (UT), ultrasonic-sodium hydroxide treatment (UST), ultrasonic-enzyme treatment (UET), and ultrasonic-microwave treatment (UMT) were used to treat sweet potatoes. The structural, physicochemical, and functional properties of the extracted soluble dietary fibres (SDFs) were named WT-SDF, UT-SDF, UST-SDF, UET-SDF, and UMT-SDF, respectively. Scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), thermal properties, and Brunauer-Emmett-Teller (BET) analysis were employed. The structural results indicated that the UST-SDF exhibited the best thermal stability, highest crystallinity, and maximum specific surface area. Moreover, compared to hot water extraction, ultrasonic extraction, or ultrasonic extraction in combination with other methods, enhanced the physicochemical and functional properties of the SDF, including extraction yield, water-holding capacity (WHC), oil-holding capacity (OHC), glucose adsorption capacity (GAC), glucose dialysis retardation index (GDRI), sodium cholate adsorption capacity (SCAC), cholesterol adsorption capacity (CAC), nitrite ion adsorption capacity (NIAC), and antioxidant properties. Specifically, the UST-SDF and UMT-SDF showed better extraction yield, WHC, OHC, GAC, CAC, SCAC, and NIAC values than the other samples. In summary, these results indicate that UST and UMT could be applied as ideal extraction methods for sweet potato SDF and that UST-SDF and UMT-SDF show enormous potential for use in the functional food industry.

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 structural characteristics on the physicochemical properties and functional activities of dietary fiber: A review of structure-activity relationship

Dietary fibers come from a wide range of sources and have a variety of preparation methods (including extraction and modification). The different structural characteristics of dietary fibers caused by source, extraction and modification methods directly affect their physicochemical properties and functional activities. The relationship between structure and physicochemical properties and functional activities is an indispensable basic theory for realizing the directional transformation of dietary fibers' structure and accurately regulating their specific properties and activities. In this paper, since a brief overview about the structural characteristics of dietary fiber, the effect of structural characteristics on a variety of physicochemical properties (hydration, electrical, thermal, rheological, emulsifying property, and oil holding capacity, cation exchange capacity) and functional activities (hypoglycemic, hypolipidemic, antioxidant, prebiotic and harmful substances-adsorption activity) of dietary fiber explored by researchers in last five years are emphatically reviewed. Moreover, the future perspectives of structure-activity relationship are discussed. This review aims to provide theoretical foundation for the targeted regulation of properties and activities of dietary fiber, so as to improve the quality of their applied products and physiological efficiency, and then to realize high value utilization of dietary fiber resources.

Influence of Three Modification Methods on the Structure, Physicochemical, and Functional Properties of Insoluble Dietary Fiber from Rosa roxburghii Tratt Pomace

Rosa roxburghii Tratt pomace is rich in insoluble dietary fiber (IDF). This study aimed to investigate the influence of three modification methods on Rosa roxburghii Tratt pomace insoluble dietary fiber (RIDF). The three modified RIDFs, named U-RIDF, C-RIDF, and UC-RIDF, were prepared using ultrasound, cellulase, and a combination of ultrasound and cellulase methods, respectively. The structure, physicochemical characteristics, and functional properties of the raw RIDF and modified RIDF were comparatively analyzed. The results showed that all three modification methods, especially the ultrasound-cellulase combination treatment, increased the soluble dietary fiber (SDF) content of RIDF, while also causing a transition in surface morphology from smooth and dense to wrinkled and loose structures. Compared with the raw RIDF, the modified RIDF, particularly UC-RIDF, displayed significantly improved water-holding capacity (WHC), oil-binding capacity (OHC), and swelling capacity (SC), with increases of 12.0%, 84.7%, and 91.3%, respectively. Additionally, UC-RIDF demonstrated the highest nitrite ion adsorption capacity (NIAC), cholesterol adsorption capacity (CAC), and bile salt adsorption capacity (BSAC). In summary, the combination of ultrasound and cellulase treatment proved to be an efficient approach for modifying IDF from RRTP, with the potential for developing a functional food ingredient.

Modification of pea dietary fibre by superfine grinding assisted enzymatic modification: Structural, physicochemical, and functional properties

Using the optimal extraction conditions determined by response surface optimisation, the yield of soluble dietary fibre (SDF) modified by superfine grinding combined with enzymatic modification (SE-SDF) was significantly increased from 4.45 % ± 0.21 % (natural pea dietary fibre) to 16.24 % ± 0.09 %. To further analyse the modification mechanism, the effects of three modification methods-superfine grinding (S), enzymatic modification (E), and superfine grinding combined with enzymatic modification (SE)-on the structural, physicochemical, and functional properties of pea SDF were studied. Nuclear magnetic resonance spectroscopy results showed that all four SDFs had α- and β-glycosidic bonds. Fourier transform infrared spectroscopy and X-ray diffraction spectroscopy results showed that the crystal structure of SE-SDF was most severely damaged. The Congo red experimental results showed that none of the four SDFs had a triple-helical structure. Scanning electron microscopy showed that SE-SDF had a looser structure and an obvious honeycomb structure than other SDFs. Thermogravimetric analysis, particle size, and zeta potential results showed that SE-SDF had the highest thermal stability, smallest particle size, and excellent solution stability compared with the other samples. The hydration properties showed that SE-SDF had the best water solubility capacity and water-holding capacity. All three modification methods (S, E, and SE) enhanced the sodium cholate adsorption capacity, cholesterol adsorption capacity, cation exchange capacity, and nitrite ion adsorption capacity of pea SDF. Among them, the SE modification had the greatest effect. This study showed that superfine grinding combined with enzymatic modification can effectively improve the SDF content and the physicochemical and functional properties of pea dietary fibre, which gives pea dietary fibre great application potential in functional foods.

In vitro digestive properties of Dictyophora indusiata polysaccharide by steam explosion pretreatment methods

Dictyophora indusiata is medicinal and edible fungi containing various nutrients. The aim of this study was to investigate the efficient extraction and structural evolution of Dictyophora indusiata polysaccharide during the vitro digestion based on steam explosion pretreatment methods. In this study, the extraction rate of Dictyophora indusiata polysaccharide was optimized by steam explosion pretreatment methods, which was 2.46 folds that of the water extraction method. In addition, the digestion and fermentation properties of Dictyophora indusiata polysaccharide before and after steam explosion were evaluated in vitro by the changes of molecular weights, total and reducing sugars levels, surface morphology and functional groups, which showed that the structure of Dictyophora indusiata polysaccharide remained stable after salivary-gastric digestion, and partially entered the large intestine, where it could be utilized by gut microbiota. Dictyophora indusiata polysaccharide promoted the increase of beneficial bacteria Megamonas and increased the content of acetic acid, propionic acid and butyric acid, which was 2.17, 2.81, 2.43 folds that of the CON group after fermentation for 24 h, and 1.87, 2.77, 1.90 folds that of the CON group after fermentation for 48 h, respectively. This study will provide theoretical basis for the high value utilization of Dictyophora indusiata polysaccharide.

The effects of different fiber fractions from sour cherry (Prunus cerasus L.) pomace and fiber modification methods on cake quality

Sour cherry pomace is the largest byproduct of sour cherry processing with more than 0.4 million tonnes per year. In this study, sour cherry pomace powder (SCPP) has been treated individually or by a combination of microwave (MW), enzymatic hydrolysis, and high pressure to increase soluble dietary fiber (SDF) content. Then, the untreated or treated forms of SCPP, their SDF, and insoluble dietary fiber (IDF) isolates were added (5%) to the reduced-fat cake. Rheological, physical, and textural properties of the full-fat (50%) and the reduced-fat (25% fat) cakes enriched with dietary fiber (DF) were compared. SDF enrichment minimized the negative effect of fat reduction in the cake. Water absorption, mixing tolerance, hardness, and springiness values of the SDF-enriched samples were found as the lowest. Extensibility, energy, weight loss, and cohesiveness values were found to be the highest values with the addition of SDF. All treatments helped to decrease mixing tolerance, dough development, and stability time. MW was the critical treatment for DF modification. Individual MW-treated DF samples increased resistance to extension of the dough samples as compared to the untreated SDF, IDF, and SCPP. Nevertheless, SDF showed better performance in acting as a fat replacer than IDF and SCPP. PRACTICAL APPLICATION: The soluble dietary fiber (SDF) isolate minimized the negative effect of fat reduction in cakes. Water absorption and mixing tolerance of the dough were measured as the lowest. The hardness and springiness of soluble dietary fiber-enriched cakes were found to be the lowest. Extensibility and weight loss reached the highest value when SDF was used. Treatments helped decrease mixing tolerance, dough development, and stability time.

Effects of two celery fibers on the structural properties and digestibility of glutinous rice starch: A comparative study

The present study focused on the extraction of water-soluble dietary fiber (CSDF) and water-insoluble dietary fiber (CIDF) from celery. It investigated their effects on glutinous rice starch's (GRS) physicochemical, structural, and digestive properties. The results showed that as the addition of the two dietary fibers increased, they compounded with GRS to varying degrees, with the complexing index reaching 69.41 % and 60.81 %, respectively. The rheological results indicated that the two dietary fibers reduced the viscosity of GRS during pasting and inhibited the short-term regrowth of starch. The FTIR and XRD results revealed that the two fibers interacted with GRS through hydrogen bonding, effectively inhibiting starch retrogradation. Furthermore, both fibers increased the pasting temperature of GRS, thus delaying its pasting and exhibiting better thermal stability. Regarding digestibility, the starch gels containing dietary fibers exhibited significantly reduced digestibility, with RS significantly increased by 8.15 % and 8.95 %, respectively. This study provides insights into the interaction between two dietary fibers and GRS during processing. It enriches the theoretical model of dietary fiber-starch interaction and provides a reference for the application development of starch-based functional foods.

Effects of high-pressure microfluidization treatment on the structural, physiochemical properties of insoluble dietary fiber in highland barley bran

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 NO2- 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 NO2- 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.

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.

Effects of extraction methods on the physicochemical properties and functionalities of pectic polysaccharides from burdock (Arctium lappa L.)

In this work, the effects of four different extraction methods, acid (HCl), alkali (NaOH), enzymes (cellulase/pectinase), and buffer (pH 7.0) on the physicochemical properties and functionalities of burdock pectin were systematically investigated and compared. Buffer extraction gave a low yield (2.8 %) and is therefore limited in its application. The acid treatment hydrolyzed the neutral sidechains and gave a homogalacturonan content of 72.6 %. By contrast, alkali and enzymes preserved the sidechains while degrading the polygalacturonan backbone, creating a rhamnogalacturonan-I dominant structure. The branched structure, low molecular weight, and high degree of methylation (42.3 %) contributed to the interfacial adsorption, emulsifying capacity, and cellular antioxidant activity of the enzyme-extracted product. For the acid-extracted product, the strong intramolecular electrostatic repulsion restricted the formation of a contact interface to prevent coalescence of the emulsion. In addition, they did not have sufficient reducing ends to scavenge free radicals. Although a high branching size (5.0) was adopted, the low degree of methylation (19.5 %) affected the emulsifying capacity of the alkali-extracted products. These results provide useful information for pectic polysaccharides production with tailored properties.

Production, structural and functional characteristics of soluble dietary fiber from fermented okara by Penicillium expansum

Soluble dietary fiber (SDF), an important prebiotic, has attracted growing attention, due to its great health effects and wide application. This study focused on the preparation of SDF from fermented okara. The yield of SDF obtained through Penicillium expansum fermentation (FSDF) reached 45.63 % (w/w) under the optimal conditions (pH 6.7, inoculum size 9.5 %, and time 29 h) by response surface methodology, which were 1.92 and 4.43 times higher than those of phosphate-citric acid treatment and untreated okara. Infrared spectra and X-ray diffraction indicated that three SDFs had similar spectral distribution and crystalline region. Moreover, FSDF displayed looser and more porous microstructures. Meanwhile, the composition ratio of monosaccharides has changed. FSDF exhibited higher water solubility (97.46 %), glucose adsorption capacity (203.73 mg/g), sodium cholate adsorption capacity (13.07 mg/g), cholesterol adsorption capacity (6.69- 7.62 mg/g) and radical (ABTS+, hydroxyl and DPPH) scavenging capacity. Additionally, three SDFs didn't degrade by upper gastrointestinal tract and could improve the proportion of beneficial intestinal flora in vitro, such as Lactobacillus and Bifidobacterium. Overall, the FSDF prepared in this study was a functional ingredient with great potential in foods.

The effects of high-pressure, enzymatic, and high-pressure-assisted enzymatic treatment on the properties of soluble dietary fibers and their use in jelly prepared with grape waste extract

This study aimed to investigate the physicochemical attributes of soluble dietary fibers (SDFs) of grape, which were isolated after enzymatic (using cellulase [0.1 MPa/60°C/30 min]), high-pressure (HP) (100 MPa/60°C/30 min), or HP-assisted enzymatic treatment (using cellulase [100 MPa/60°C/30 min]), then to evaluate textural properties, color, and microbiological load of jelly prepared using grape waste extract and either pectin or SDF types. HP-assisted enzymatic treatment increased glucose adsorption capacity by more than 50%, and the water-holding capacity of SDF more than twofold as compared to the levels measured in untreated-SDF. After treatments, glucose and galactose contents decreased, whereas fructose, mannose, xylose, arabinose, and rhamnose ratios increased. The arabinose ratio increased more than twice by the effect of HP, whereas the xylose content increased almost fivefold with HP-assisted enzymatic treatment. For the textural properties of jelly, HP-assisted enzymatic treated-SDF provided almost double values in gel strength and adhesiveness than those contributed by untreated-SDF. It was followed by HP-treated SDF jelly. The results showed that HP-assisted enzymatic treatment developed more similar outcomes with enzymatic treatment, rather than HP treatment alone. HP-assisted enzymatic hydrolysis is recommended for treating SDF for use in jelly due to its synergistic effect. PRACTICAL APPLICATION: High-pressure-assisted cellulase treatment provided the best properties to SDF for jelly. In combined treatment, impacts of cellulase treatment were more prominent than HP effects. Therefore, the use of HP assistance for enzymatic hydrolysis shortens the processing time. Moreover, the technological and functional properties (water holding, glucose adsorption capacity, and monosaccharide composition) of the combined treated-fiber can improve. In addition, the color and textural properties of the jelly prepared with this treated-fiber can be enhanced. In this way, it may be possible to obtain a good thickening agent. This material can also be an alternative to pectin.

The characteristics of microwave-treated insoluble and soluble dietary fibers from grape and their effects on bread quality

This study investigated the morphological and hydration properties of untreated and microwave (MW)-treated isolate forms of soluble (SDF) and insoluble dietary fibers (IDF) obtained from grapes. Then, the rheological, textural, and other physical effects of the fibers (5% flour basis) were evaluated on bread quality. For this purpose, grape pomace was valorized as the juice extraction waste. MW significantly improved hydration properties of SDF and IDF by modifying their microstructures (p < .05). SDF had a clean-cut morphology whereas IDF had an indented microstructure with a wrinkled surface. After MW treatment, deep grooves and holes were observed. These variations in the IDF structure were more extensive. DF additions influenced water absorption, mixing tolerance index, dough development time, dough stability, resistance to extension, extensibility, energy of the dough and hardness, cohesiveness, springiness, chewiness, weight loss, specific volume, crust color difference of the bread in comparison with the properties of control samples significantly (p < .05). IDF had especially pronounced effects on the dough and bread characteristics. SDF enrichment provided more comparable results with the control bread than IDF. The originality of this work is to characterize isolated (100% purity) SDFs and IDFs, then discuss their effects on semi (dough) and final (bread) product quality.

The Progressive Utilization of Ponkan Peel Residue for Regulating Human Gut Microbiota through Sequential Extraction and Modification of Its Dietary Fibers

As a by-product of citrus processing, ponkan (Citrus reticulata Blanco, cv. Ponkan) peel residue is a source of high quality dietary fiber (DF). To make a full utilization of this resource and give a better understanding on the probiotic function of its DF, soluble dietary fiber (SDF) and insoluble dietary fiber (IDF) were extracted from ponkan peel residue (after flavonoids were extracted) using an alkaline method, followed by modifications using a composite physical-enzymatic treatment. The in vitro fermentation properties of the modified SDF and IDF (namely, MSDF and MIDF) and their effects on short-chain fatty acids (SCFA) production and changes in the composition of human gut microbiota were investigated. Results showed that MSDF and MIDF both significantly lowered the pH value and enhanced total SCFA content in the broths after fermented for 24 h by fecal inocula (p < 0.05) with better effects found in MSDF. Both MSDF and MIDF significantly reduced the diversity, with more in the latter than the former, and influenced the composition of human gut microbiota, especially increasing the relative abundance of Bacteroidetes and decreasing the ratio of Firmicutes to Bacteroidetes (F/B) value. The more influential microbiota by MSDF were g-Collinsella, p-Actinobacteria and g-Dialister, while those by MIDF were f-Veillonellaceae, c-Negativicutes and f-Prevotellacese. These results suggested that the modified ponkan peel residue DF can be utilized by specific bacteria in the human gut as a good source of fermentable fiber, providing a basis for the exploitation of the citrus by-product.

Release characteristic of bound polyphenols from tea residues insoluble dietary fiber by mixed solid-state fermentation with cellulose degrading strains CZ-6 and CZ-7

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.

Comparison on structure, properties and functions of pomegranate peel soluble dietary fiber extracted by different methods

In this research, the different methods (acid extraction, alkaline extraction and enzymatic extraction) were used to extract soluble dietary fiber (SDF) from pomegranate peel and compared with water extraction. Results revealed that all three extraction methods influenced the structure, physicochemical and functional properties of SDF. Especially, SDF extracted by enzymes (E-SDF) and SDF extracted by alkali (A-SDF) had higher yield (27.30% and 27.17%), molecular weight and thermal stability than SDF extracted by water (W-SDF). Higher oil holding capacity (OHC) was found in SDF extracted by acid (C-SDF) (3.18 g/g), A-SDF (3.18 g/g) and E-SDF (5.36 g/g) compared with W-SDF. In addition, A-SDF showed the smallest particle size, lowest ζ-potential and highest viscosity among the tested samples. E-SDF presented a more porous structure, better glucose adsorption capacity (GAC) and antioxidant activity than C-SDF and A-SDF. To sum up, A-SDF and E-SDF may have great potential to be functional food ingredients in the food 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.

Physicochemical properties of superfine grinding-microwave modified artichoke soluble dietary fiber and their alleviation of alcoholic fatty liver in mice

The effects of superfine grinding (SG) and microwave treatment (MT) on the structure and physicochemical properties of artichoke soluble dietary fiber (ASDF) and its protective effects on mice with alcoholic fatty liver (AFL) were studied. We compared the changes in structural characteristics and physicochemical properties of ASDF, SG-ASDF (ASDF treated by SG), MT-ASDF (ASDF treated by MT), and CM-ASDF (ASDF treated by SG and MT). Moreover, we evaluated the effects of the obtained ASDF on the growth characteristics, blood lipid levels, and liver of mice with AFL. Our results of the study showed that CM-ASDF had a more concentrated and uniform particle size, a higher extraction rate of ASDF and significantly improved water-holding capacity (WHC), oil-holding capacity (OHC) and water swelling capacity (WSC) of ASDF (p < 0.05). After the ASDF intervention, mice with AFL exhibited a significant improvement in body lipid levels and reduce liver inflammation. Specifically, aspartate aminotransferase (AST), alanine aminotransferase (ALT), malonaldehyde (MDA), Tumor necrosis factor-α (TNF-α) and Interleukin-6 (IL-6) were significantly decreased, while superoxide dismutase (SOD) and glutathione peroxidase (GSH-PX) were significantly increased (p < 0.05). And the hematoxylin-eosin (HE) staining results showed significant improvement of hepatic steatosis in mice with AFL. In summary, our study found that both SG and MT could improve the structure and physicochemical properties of ASDF, with CM-ASDF being the most effective. Additionally, CM-ASDF was selected to continue the investigation and demonstrated an excellent protective effect on mice with AFL, with the high dose group (H-ASDF) showing the greatest benefit. These findings provided some new insights for future comprehensive utilization of ASDF and drug development for the treatment of AFL.

Dietary fiber extraction from citrus peel pomace: Yield optimization and evaluation of its functionality, rheological behavior, and microstructure properties

Citrus fruits were widely used in processing and production, generating a large amount of peel pomace and a low utilization rate, resulting in substantial economic losses and environmental risks. It was important to extract compounds from citrus peel pomaces and find suitable preparation methods to improve their yield and physicochemical properties. Grapefruit peel pomace (GP) and navel orange peel pomace (OP) were used as raw materials in this study to prepare green and edible soluble dietary fiber (SDF) and insoluble dietary fiber (IDF). Analysis was done on the effects of solid-liquid ratio, cellulase hydrolysis time, cellulase dosage, and ultrasonic time on dietary fiber (DF) yield. To obtain the best DF preparation conditions, we used range analysis, variance analysis, and orthogonal experimental design. We also analyzed the structural, physicochemical, and rheological characteristics of SDF and IDF. According to the study's findings, SDF and IDF showed a loose and expansive structure with reduced particle size, higher specific surface area, and noticeably better physical and chemical properties after treating GP and OP with ultrasound-assisted composite enzyme method. Both SDF solution and IDF suspension were discovered through rheological analysis to be non-Newtonian pseudoplastic fluids, which was advantageous for expanding their applications in the field of food packaging. In conclusion, DF prepared using the ultrasound-assisted composite enzyme method was an excellent source of edible packaging materials, offering a benchmark for the recycling of other citrus peel wastes and ultimately paving the way for new methods of recycling citrus waste.

Sustainable Nonfarm Approaches to Achieve Zero Hunger and Its Unveiled Reality

Millions of people worldwide are deprived of sufficient, safe, and nutritious food required for an everyday and healthy life. The hunger crisis is worsening over time, even though many attempts have been made to minimize it. Increasing world population and competition for natural resources, climate change, natural disasters, urbanization, poverty, and illiteracy are the main causes that need to be addressed to reduce the hunger crisis. Various nonfarm technologies are being used to eradicate hunger but their long-term impact on the environment should also be considered. The real sustainability of several novel technologies being implemented to deal with hunger is an issue to tackle. This paper discusses the potential applications of storage facilities, underutilized crops, waste valorization, food preservation, nutritionally enriched novel food products, and technological advancement in food processing to achieve zero hunger. An attempt has also been made to address the sustainability of various nonfarm technology utilized to minimize the global hunger crisis.

Effects of Four Extraction Methods on Structure and In Vitro Fermentation Characteristics of Soluble Dietary Fiber from Rape Bee Pollen

In this study, soluble dietary fibers (SDFs) were extracted from rape bee pollen using four methods including acid extraction (AC), alkali extraction (AL), cellulase extraction (CL) and complex enzyme extraction (CE). The effects of different extraction methods on the structure of SDFs and in vitro fermentation characteristics were further investigated. The results showed that the four extraction methods significantly affected the monosaccharide composition molar ratio, molecular weight, surface microstructure and phenolic compounds content, but showed little effect on the typical functional groups and crystal structure. In addition, all SDFs decreased the Firmicutes/Bacteroidota ratio, promoted the growth of beneficial bacteria such as Bacteroides, Parabacteroides and Phascolarctobacterium, inhibited the growth of pathogenic bacteria such as Escherichia-Shigella, and increased the total short-chain fatty acids (SCFAs) concentrations by 1.63-2.45 times, suggesting that the bee pollen SDFs had a positive regulation on gut microbiota. Notably, the SDF obtained by CE exhibited the largest molecular weight, a relatively loose structure, higher extraction yield and phenolic compounds content and the highest SCFA concentration. Overall, our results indicated that CE was an appropriate extraction method of high-quality bee pollen SDF.

Effect of Insoluble Dietary Fiber Extracted from Feijoa (Acca sellowiana (O. Berg) Burret.) Supplementation on Physicochemical and Functional Properties of Wheat Bread

This study aimed to assess the effects of insoluble dietary fiber (IDF) from feijoa supplementation on the physicochemical and functional properties of wheat bread. The results showed that feijoa IDF (FJI) had the typical structures of hydrolysis fiber, polysaccharide functional groups, and crystal structure of cellulose. The gradual increase of FJI levels (from 2 to 8%) in wheat bread resulted in increased total DF, ash, and protein contents, accompanied by a reduction in moisture, carbohydrates, and energy value. The inclusion of FJI in the bread crumb caused a rise in both redness (a*) and yellowness (b*) values while decreasing the brightness (L*) relative to the control specimen. In addition, adding FJI up to 2% significantly increased total phenolic and flavonoid contents and antioxidant activity, as well as flavor score of supplemented bread samples, while additions above 2% resulted in undesirable taste and texture. FJI addition caused higher bile acid, NO2-, and cholesterol adsorption capacities. Moreover, FJI addition up to 4% significantly reduced glucose adsorption capacities at different in vitro starch digestion intervals. The findings revealed that FJI offers great potential as an ideal functional ingredient in food processing.

Characterization of manganized soluble dietary fiber complexes from tigernut meal and study of the suppressive activity of digestive enzymes in vitro

In this study, manganized soluble dietary fiber (SDF-Mn(II)) was prepared from tigernut meal using a microwave solid-phase synthesis method with SDF. Microscopic morphological and structural analyses of SDF-Mn(II) were carried out using scanning electron microscopy, Fourier infrared spectroscopy, UV full-band scanning, X-ray diffraction, a thermal analyzer, gel permeation chromatography, and nuclear magnetic resonance, and its in vitro hypoglycemic activity was initially investigated. The results of these analyses revealed that the reaction of Mn(II) with SDF mainly involved hydroxyl and carbonyl groups, with the Nuclear magnetic resonance (NMR) analysis showing that specific covalent binding was produced and substitution was mainly carried out at the C₆ position. Moreover, compared with SDF, the SDF-Mn(II) complex exhibited a porous structure, red-shifted, and color-enhancing effects on the UV characteristic peaks, significantly increased crystallinity and decreased molecular weight, and improved thermal stability; in addition, SDF-Mn(II) afforded significantly enhanced inhibition of α-amylase and α-glucosidase and possesses good in vitro digestive enzyme inhibition activity.

The structural and functional properties of dietary fibre extracts obtained from highland barley bran through different steam explosion-assisted treatments

The effects of steam explosion (SE)-assisted ultrasound (SEU), citric acid (SEC), sodium hydroxide (SEA), and cellulase (SEE) treatment on the properties of soluble dietary fibre (SDFP) extracted from highland barley bran were analysed. The results showed that SE pretreatment combined with other methods effectively improves the SDFP yield. The highest yield of SDF (20.01%) was obtained through SEA treatment. SEU-SDFP had a loose and porous structure, whereas the surface of SEC-SDFP and SEA-SDFP presented a complicated and dense texture. Although SE pretreatment reduced the thermal stability of SDFP, SEC and SEE treatment maintained its thermal stability. Furthermore, SEU-SDFP exhibited the highest water and oil holding capacities, and cholesterol and nitrite ion adsorption capacities. SEE-SDFP exhibited the best DPPH and ABTS radical scavenging abilities. In summary, four SE-assisted extraction methods had different advantages, and highland barley bran SDF can be considered as a potential functional additive in the food industry.

Fermentation of grapefruit peel by an efficient cellulose-degrading strain, (Penicillium YZ-1): Modification, structure and functional properties of soluble dietary fiber

In the study, a highly efficient cellulose-degrading strain was screened, which was identified as a fungus in the genus Penicillium sp., named YZ-1. The content of soluble dietary fiber was greatly increased by the treatment of this strain. In addition, the effects of soluble dietary fiber from high-pressure cooking group (HG-SDF), strain fermentation group (FG-SDF) and control group (CK-SDF) on the physicochemical structure, and in vitro hypolipidemic activity were investigated. The results showed that the physicochemical structure of the raw materials was improved after fermentation, and FG-SDF exhibited the loosest structure, the highest viscosity and thermal stability. Furthermore, compared to CK-SDF and HG-SDF, FG-SDF showed the most significant improvement in functional properties, including cholesterol adsorption capacity (CAC), inhibition of pancreatic lipase activity (LI) and mixed bile acid adsorption capacity (BBC). Overall, these findings will provide new insights into dietary fiber modification and improve the comprehensive use value of grapefruit by-products.