Effect of four modification methods on adsorption capacities and in vitro hypoglycemic properties of millet bran dietary fibre

Quality, improvement of soluble dietary fiber from Dictyophora indusiata by-products by steam explosion and cellulase modification: Structural and functional analysis

Steam explosion (SE) and cellulase treatment are potentially effective processing methods for Dictyophora indusiata by-products, for use in high-value applications. The treatment conditions were optimized by response surface methodology, increasing the soluble dietary fiber (SDF) yield by 1.52 and 1.16 times after the SE and cellulase treatments, respectively. The both treatments did not affect the functional groups and crystal types of the polysachharides, but both reduced the crystallinity. The SDF had a porous microstructure, which would increase the specific surface area and facilitates the adsorption of water and glucose, thereby improving its functional properties. SE and cellulase treatment significantly improved the hydration capacity of SDF; the glucose adsorption capacity increased by 1.15 and 1.07 times, respectively. Overall, the modified SDF showed different degrees of advantages in terms of yield, physicochemical and functionality. This study demonstrated that SE and cellulase are effective modification methods for SDF made from D. indusiata by-products.

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.

Physiochemical, Bio, Thermal, and Non-Thermal Processing of Major and Minor Millets: A Comprehensive Review on Antinutritional and Antioxidant Properties

Millets are recognized as future foods due to their abundant nutrition and resilience, increasing their value on the global stage. Millets possess a broad spectrum of nutrients, antinutrients, and antioxidants, making it imperative to understand the effects of various processing methods on these components. Antinutritional factors interfere with the digestibility of macro-nutrients and the bioavailability and bio accessibility of minerals. This necessitates methods to reduce or eliminate antinutrients while improving nutritive and antioxidant value in food. This review aims to elucidate the rationale behind processing choices by evaluating the scientific literature and examining the mechanisms of processing methods, categorized as physiochemical, bio, thermal, novel non-thermal, and their combination techniques. Physiochemical and bioprocessing methods alter antinutrients and antioxidant profiles through mass transfer, enzyme activation, product synthesis, microbial activity, and selective removal of grain layers. Thermal methods break functional bonds, modify the chemical or physical structures, enhance kinetics, or degrade heat-labile components. Non-thermal techniques preserve heat-sensitive antioxidants while reducing antinutrients through structural modifications, oxidation by ROS, and break down the covalent and non-covalent bonds, resulting in degradation of compounds. To maximize the trade-off between retention of beneficial components and reducing detrimental ones, exploring the synergy of combination techniques is crucial. Beyond mitigating antinutrients, these processing methods also stimulate the release of bioactive compounds, including phenolics, flavonoids, and peptides, which exhibit potent health-promoting properties. This review underscores the transformative potential of processing technologies in enhancing millets as functional ingredients in modern diets, promoting health and advancing sustainable food practices.

How lignocellulose degradation can promote the quality and function of dietary fiber from bamboo shoot residue by Inonotus obliquus fermentation

Lignocellulose constitutes the primary component of dietary fiber. We assessed how fermenting bamboo shoot residue with the medicinal white-rot fungus Inonotus obliquus affected the yield, composition, and functional attributes of dietary fiber by altering bamboo shoot residue lignocellulose's spatial structure and composition. I. obliquus secretes lignocellulolytic enzymes, which effectively enhance the degradation of holocellulose and lignin by 87.8% and 25.5%, respectively. Fermentation led to a more porous structure and reduced crystallinity. The yield of soluble dietary fiber increased from 5.1 g/100 g raw BSR to 7.1 g/100 g 9-day-fermented bamboo shoot residue. The total soluble sugar content of dietary fiber significantly increased from 9.2% to 13.8%, which improved the hydration, oil holding capacity, in vitro cholesterol, sodium cholate, and nitrite adsorption properties of dietary fiber from bamboo shoot residue. These findings confirm that I. obliquus biotransformation is promising for enhancing dietary fiber yield and quality.

Ball Milling Improves Physicochemical, Functionality, and Emulsification Characteristics of Insoluble Dietary Fiber from Polygonatum sibiricum

The effects of ball milling on the physicochemical, functional, and emulsification characteristics of Polygonatum sibiricum insoluble dietary fiber (PIDF) were investigated. Through controlling milling time (4, 5, 6, 7, and 8 h), five PIDFs (PIDF-1, PIDF-2, PIDF-3, PIDF-4, and PIDF-5) were obtained. The results showed that ball milling effectively decreased the particle size and increased the zeta-potential of PIDF. Scanning electron microscope results revealed that PIDF-5 has a coarser microstructure. All PIDF samples had similar FTIR and XRD spectra. The functional properties of PIDF were all improved to varying degrees after ball milling. PIDF-3 had the highest water-holding capacity (5.12 g/g), oil-holding capacity (2.83 g/g), water-swelling capacity (3.83 mL/g), total phenol (8.12 mg/g), and total flavonoid (1.91 mg/g). PIDF-4 had the highest ion exchange capacity. Fat and glucose adsorption capacity were enhanced with ball milling time prolongation. PIDF-5 exhibited a contact angle of 88.7° and lower dynamic interfacial tension. Rheological results showed that PIDF-based emulsions had shear thinning and gel-like properties. PE-PIDF-5 emulsion had the smallest particle size and the highest zeta-potential value. PE-PIDF-5 was stable at pH 7 and high temperature. The findings of this study are of great significance to guide the utilization of the by-products of Polygonatum sibiricum.

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.

Effects of soluble dietary fiber from pomegranate peel on the physicochemical properties and in-vitro digestibility of sweet potato starch

The effects of soluble dietary fiber (SDF) from pomegranate peel obtained through enzyme (E-SDF) and alkali (A-SDF) extractions on the structural, physicochemical properties, and in vitro digestibility of sweet potato starch (SPS) were investigated. The expansion degree of SPS granules, pasting viscosity, gel strength and hardness were decreased after adding E-SDF. The setback was accelerated in the presence of A-SDF but E-SDF delayed this effect during the cooling of the starch paste. However, the addition of A-SDF significantly reduced the breakdown of SPS and improved the freeze-thaw stability of starch gels, even at low concentrations (0.1 %), while E-SDF showed the opposite result. The structural characterization of SDF-SPS mixtures showed that A-SDF can help SPS form an enhanced microstructure compared with E-SDF, while polar groups such as hydroxyl group in E-SDF may bind to leached amylose through hydrogen bonding, leading to a decrease in SPS viscoelasticity. In addition, the results of in vitro digestion analysis indicated that A-SDF and E-SDF could decreased the digestibility of SPS and increased the content of resistant starch, especially when 0.5 % E-SDF was added. This study provides a new perspective on the application of SDF from pomegranate peel in improving starch-based foods processing and nutritional characteristics.

Effects of steam explosion-modified rice bran dietary fiber on volatile flavor compounds retention and release of red date-flavored naan (ethnic specialty food of Xinjiang) during storage

This study explored the effects of steam explosion-modified rice bran dietary fiber (S-RBDF) on red date-flavored naan quality and flavor characteristics. The results revealed that the rheological properties of the dough were improved with the incremental addition of S-RBDF (0-5%). The microstructure revealed that adding an appropriate amount of S-RBDF (1-5%) enabled more starch granules to be embedded in the dough network. Notably, the addition of 5% S-RBDF resulted in naan with an optimum specific volume and texture, which consumers preferred. Additionally, gas chromatography-mass spectrometry analysis showed that adding S-RBDF to naan contributed to the retention and sustained release of pleasant volatile compounds (e.g. red date flavor, etc.), while inhibiting the development of unpleasant volatile compounds by delaying the oxidation and decomposition of lipids and preserving the antioxidant phenolic compounds, thus contributing to flavor maintenance of naan during storage. Overall, these results provided a foundation for developing high-quality flavored naan.

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.

Chinese bayberry (Myrica rubra Sieb. et Zucc.) leaves proanthocyanidins inhibit intestinal glucose transport in human Caco-2 cells

Background: The hypoglycemic effects of Chinese bayberry leaves proanthocyanidins (BLPs) have been demonstrated. It is unclear, nevertheless, whether BLPs reduced postprandial blood glucose levels by regulating glucose uptake and glucose transport. Method: This study investigated the effect of BLPs (25, 50, and 100 μg/mL) on glucose uptake and glucose transport in human intestinal epithelial cells (Caco-2 cells). The uptake of 2-Deoxy-2-[(7-nitro-2,1,3-benzoxadiazol-4-yl) amino]-D-glucose (2-NBDG) and disaccharidases activity in Caco-2 cells were measured. The glucose transport ability across the cell membrane was determined using the established Caco-2 monolayer model. The transcript and protein levels of key glucose transporters were analyzed using real-time quantitative polymerase chain reaction (RT-qPCR) and western blotting, respectively. Results: The results showed that BLPs significantly decreased glucose uptake and disaccharidases activity (p < 0.05). Otherwise, BLPs treatment obviously inhibited glucose transport across the Caco-2 monolayer in both simulated-fast (5 mM glucose) and simulated-fed (25 mM glucose) conditions. It was attributed to the suppression of glucose transporter2 (GLUT2) and sodium-dependent glucose cotransporter 1 (SGLT1) by BLPs. BLPs were found to significantly downregulated the transcript level and protein expression of glucose transporters (p < 0.05). Meanwhile, the mRNA expression of phospholipase C (PLC) and protein kinase C (PKC) involved in the signaling pathway associated with glucose transport were decreased by BLPs. Conclusion: These results suggested that BLPs inhibited intestinal glucose transport via inhibiting the expression of glucose transporters. It indicated that BLPs could be potentially used as a functional food in the diet to modulate postprandial hyperglycemia.

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.

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.

Improving the quality of soluble dietary fiber from Poria cocos peel residue following steam explosion

Poria cocos peel residue (PCPR) still contains much soluble dietary fiber (SDF), steam explosion (SE) treatment was applied to PCPR to create a superior SDF. Steam pressure of 1.2 MPa, residence period of 120 s, and moisture content of 13% were the optimized parameters for SE treatment of PCPR. Under optimized circumstances, SE treatment of PCPR enhanced its SDF yield from 5.24% to 23.86%. Compared to the original SDF, the SE-treated SDF displayed improved enzyme inhibition, including the inhibition of α-amylase and pancreatic lipase, also enhanced water holding, oil holding, water swelling, nutrient adsorption including cholesterol, nitrite ions, and glucose and antioxidant abilities. Additionally, it had a decreased molecular weight, improved thermal stability, and a rough surface with many pores of different sizes. Given that SDF had been improved physiochemical and functional characteristics thanks to SE treatment, it might be the excellent functional ingredient for the food business.

Effects of Alkaline Hydrogen Peroxide and Cellulase Modifications on the Physicochemical and Functional Properties of Forsythia suspensa Dietary Fiber

Besides active substances, Forsythia suspensa is rich in dietary fiber (DF), but it is often wasted or discarded and not put to good use. In order to improve the function of Forsythia DF, it was modified using alkaline hydrogen peroxide (AHP) and cellulase (EM). Compared to the control DF (ODF), the DF modified using AHP (AHDF) and EM (EMDF) had a looser microstructure, lower crystallinity, and higher oil holding capacity (OHC) and cation exchange capacity (CEC). The AHP treatment significantly increased the water holding capacity (WHC) and water swelling ability (WSA) of the DF, while the EM treatment achieved just the opposite. Moreover, the functional properties of AHDF and EMDF, including their cholesterol adsorption capacity (CAC), nitrite ion adsorption capacity (NAC), glucose adsorption capacity (GAC), glucose dialysis retardation index (GDRI), α-amylase inhibitory activity, and DPPH radical scavenging activity, were far better than those of ODF. Together, the results revealed that AHP and EM modifications could effectively improve or enhance the physicochemical and functional properties of Forsythia suspensa DF.

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.

Effects of three biological combined with chemical methods on the microstructure, physicochemical properties and antioxidant activity of millet bran dietary fibre

The effects of cellulase hydrolysis separately combined with hydroxypropylation, carboxymethylation and phosphate crosslinking on the physicochemical properties and antioxidant activity of millet bran dietary fibre (MBDF) were investigated. Compared to cellulase hydrolysis alone, these dual modifications more effectively improved the soluble fibre content, water-swelling ability, viscosity, emulsifying capacity and cation-exchange capacity of MBDF but reduced the emulsion stability, brightness and polyphenol content of MBDF (P < 0.05). MBDF modified by cellulase hydrolysis combined with hydroxypropylation showed the highest emulsifying capacity (60.03 m²/g) and oil-adsorption capacity (3.32 g/g) but the lowest nitrite ion-adsorbing ability (NIAA). MBDF modified by cellulase hydrolysis with carboxymethylation showed the highest surface hydrophobicity, cation-exchange capacity (0.352 mmol/g) and NIAA (152.89 μg/g). MBDF modified by cellulase hydrolysis combined with phosphate crosslinking exhibited excellent copper ion-adsorbing ability (19.97 mg/g) and viscosity (19.33 cp). Moreover, these dual modifications all enhanced the Fe²⁺ chelating ability and reducing power of MBDF (P < 0.05).

Effects of shear emulsifying/ball milling/autoclave modification on structure, physicochemical properties, phenolic compounds, and antioxidant capacity of lotus (Nelumbo) leaves dietary fiber

Lotus (Nelumbo) leaves are rich in polyphenols and dietary fiber, which have the potential as a high-quality fiber material in functional food. However, lotus leaves exhibit dense structure and poor taste, it is vital to develop appropriate modification methods to improve the properties of lotus leaves dietary fiber. In this study, the effects of three modification methods with shear emulsifying (SE), ball milling (BM), and autoclave treatment (AT) on structure, physicochemical properties, phenolic compounds, and antioxidant capacity of lotus leave dietary fiber (LDF) were evaluated. SEM indicated that there were significant differences in the microstructure of modified LDFs. FT-IR spectra and X-ray diffraction pattern of modified LDFs revealed similar shapes, while the peak intensity and crystalline region changed by modification. SE showed the greatest effect on crystallization index. SE-LDF had the highest water holding capacity, water swelling capacity, and bound phenolic content in LDFs, which increased by 15.69, 12.02, and 31.81%, respectively, compared with the unmodified LDF. BM exhibited the most dramatic effect on particle size. BM-LDF had the highest free phenolic and total phenolic contents in LDFs, which increased by 32.20 and 29.05% respectively, compared with the unmodified LDF. Phenolic compounds in LDFs were mainly free phenolic, and modifications altered the concents of flavonoids. The BM-LDF and SE-LDF exhibited higher antioxidant capacity than that of AT-LDF. Overall, SE-LDF showed better physical properties, and BM-LDF showed better bioactive components. SE and BM were considered to be appropriate modification methods to enhance the properties of LDF with their own advantages.

Physicochemical, structure properties and in vitro hypoglycemic activity of soluble dietary fiber from adlay (Coix lachryma-jobi L. var. ma-yuen Stapf) bran treated by steam explosion

To enhance the content of adlay bran soluble dietary fiber (SDF) and improve its functionality, we investigated the influences of steam explosion (SE) on the physicochemical, structural properties, and in vitro hypoglycemic activities of adlay bran SDF. The cellulose, hemicellulose, and lignin contents of adlay bran decreased significantly after SE treatment. When the SE strength was 0.8 MPa for 3 min, the SDF content was 9.37%, which was a significant increase of 27.48% compared to the control. Under these conditions, SDF showed the highest oil-holding capacity (OHC) (2.18 g/g), cholesterol adsorption capacity (CAC) (27.29 mg/g), glucose adsorption capacity (GAC) (15.54 mg/g), glucose dialysis retardation index (GDRI) (36.57%), and α-Amylase activity inhibition ratio (α-AAIR) (74.14%). Compared with SDF from untreated adlay bran, SDF from SE-treated adlay bran showed lower weight molecular. In addition, differential scanning calorimetry (DSC) measurement showed that the peak temperature of SDF from adlay bran treated by SE increased by 4.19°C compared to the untreated SDF sample. The structure of SDF from adlay bran treated by SE showed that the SDF surface was rough and poriferous and the specific surface areas increased. In conclusion, SE pretreatment increases the content of SDF in adlay bran and improves its physicochemical, structural properties, and biological activities, which will be beneficial for the further exploitation of adlay bran.

Effects of electron beam irradiation treatment on the structural and functional properties of okara insoluble dietary fiber

BACKGROUND

Insoluble dietary fiber (IDF) has beneficial physiological effects, such as the promoting of intestinal peristalsis, the improving of intestinal flora, and the absorbing of some harmful substances. Okara, a byproduct of soybean processing, is a potential source of IDF. But the larger particle size and poor water solubility of okara IDF have adverse effects on sensory properties and functional characteristics. Therefore, we used an emerging type of physical method is electron beam irradiation (EBI) to modify okara, and investigated that the effects of EBI doses on the structure and functional properties of okara IDF.

RESULTS

It was found that the electron beam treatment damaged the crystalline structure of IDF. Observation of the surface of EBI-treated IDF revealed a loose and porous morphology rather than the typical smooth structure. At a dose of 6 kGy, a smallest particle size and largest specific surface area of IDF was obtained, and these factors increased the apparent viscosity of an IDF dispersion. The water holding capacity, swelling capacity and the oil holding capacity upon irradiation at 6 kGy increased 74.13%, 84.76% and 41.62%, respectively. In addition, the capacity for adsorption of cholesterol, sodium cholate, glucose and nitrite ion were improved after electron beam treatment.

CONCLUSION

The modified okara IDF showed improved particle sizes and hydration properties, and these changes correlated with an improvement to the rough taste of IDF and improvements to the texture and storage period upon supplementation into food. © 2022 Society of Chemical Industry.

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.

The effect of ball milling on the structure, physicochemical and functional properties of insoluble dietary fiber from three grain bran

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

Physicochemical structure and functional properties of soluble dietary fibers obtained by different modification methods from Mesona chinensis Benth. residue

Alkaline hydrogen peroxide (AHP), high-temperature cooking combined with ultrasonic (HTCU) and high-temperature cooking combined with complex enzyme hydrolysis (HTCE) were used to modify soluble dietary fiber (SDF) in Mesona chinensis Benth. residue (MCBR), then the structural and in vitro functional properties of A-SDF, HU-SDF and HE-SDF were investigated. Results showed that the three treatments significantly increased the yield of SDF. Scanning electron microscopy, FT-IR, monosaccharide composition, X-ray diffraction, molecular weight distribution and thermal stability analysis were employed to determine the structural changes. Compared with the control SDF (CK-SDF), HE-SDF and HU-SDF had looser and more porous microstructure, as well as lower crystallinity. In contrast to HE-SDF and HU-SDF, A-SDF exhibited a dense wavy microstructure, and elevated crystallinity and thermal stability. In addition, the monosaccharide composition and molecular weight of HU-SDF, HE-SDF and A-SDF were significantly altered as compared to CK-SDF. Moreover, the functional properties of HE-SDF and HU-SDF, including water holding capacity (WHC), oil holding capacity (OHC), glucose adsorption capacity (GAC), α-amylase activity inhibition ratio (α-AAIR), cholesterol adsorption capacity (CAC) and nitrite ion adsorption capacity (NIAC), were significantly higher than those of CK-SDF. However, the dense structure and high crystallinity of A-SDF resulted in a significantly lower GAC and NIAC than that of CK-SDF, with only WHC and α-AAIR being improved. Overall, this study showed that HTCU and HTCE could be used as ideal modification methods for MCBR SDF, HE-SDF and HU-SDF have potential as functional additives in food.

Characterization of Berry Pomace Powders as Dietary Fiber-Rich Food Ingredients with Functional Properties

This study aimed to evaluate and compare the dried pomace powder of cranberries, lingonberries, sea buckthorns, and black currants as potential food ingredients with functional properties. The composition and several physicochemical and adsorption properties associated with their functionality were investigated. Tested berry pomace powders were rich in dietary soluble fiber (4.92–12.74 g/100 g DM) and insoluble fiber (40.95–65.36 g/100 g DM). The highest level of total phenolics was observed in the black currant pomace (11.09 GAE/g DM), whereas the sea buckthorn pomace revealed the highest protein concentration (21.09 g/100 g DM). All the berry pomace powders that were tested exhibited good water-holding capacity (2.78–4.24 g/g) and swelling capacity (4.99–9.98 mL/g), and poor oil-binding capacity (1.09–1.57 g/g). The strongest hypoglycemic properties were observed for the lingonberry and black currant pomace powders. The berry pomace powders presented effective in vitro hypolipidemic properties. The cholesterol-binding capacities ranged from 21.11 to 23.13 mg/g. The black currant and cranberry pomace powders demonstrated higher sodium-cholate-binding capacity than those of the lingonberry and sea buckthorn pomace powders. This study shows promising results that the powders of tested berry pomace could be used for further application in foods.