Soybean Fiber Research Articles

Improving emulsifying properties of okara-derived insoluble soybean fiber (ISF): contribution of steam-cooking processing and various fractions of ISF

In response to the low utilization and poor emulsifying properties of insoluble soybean fiber (ISF) derived from okara, this work aimed to improve the structural-physicochemical properties of ISF by steam-cooking process through adjusting the pH, temperature and duration. The effects of soluble and insoluble fractions of ISF on its emulsifying properties were investigated. Increased temperature to 120 °C and prolonged durations of steam-cooking at pH 3 disintegrated the ISF matrix and reduced the aggregation, while notable aggregation was observed at pH 11 and 120 °C. The heightened steam-cooking intensity led to stronger hydrogen bonding within ISF, accompanied by the increase in crystallinity index from 26.7%–30.8% to 40.1%–44.2%. Additionally, there was a notable enhancement in gel-like properties, as evidenced by the elastic modulus of ISF suspensions increasing from 0.3–247.2 Pa to 1048.0–1355.0 Pa. The steam-cooking positively influenced the surface wettability and emulsifying properties of ISF, particularly evident by the near-neutral contact angle of ISF steam-cooked at 120 °C, resulting in emulsions with finer droplets. The microstructure and apparent viscosity of the emulsions were primarily influenced by the insoluble fractions, despite the higher capability of soluble fractions to reduce interfacial tension. The insoluble fractions prevented droplet aggregation by facilitating the formation of droplet clusters. Overall, steam-cooking improved the emulsifying properties of ISF by modulating composition and physicochemical properties, providing promising applications for ISF as food ingredients in emulsions and gels.

Extraction of insoluble soybean fiber by alternating ultrasonic/alkali and its improved superior physicochemical and functional properties

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

A novel set-type yogurt with improved rheological and sensory properties by the sole addition of insoluble soybean fiber

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

Effects of physical method and enzymatic hydrolysis on the properties of soybean fiber-rich stabilizer for oil in water emulsions.

Okara is a by-product from the soybean industry and an abundant resource of insoluble soybean fiber (ISF). ISF with various properties could be obtained by different extraction methods. It is an attractive option to utilize okara by taking advantage of ISF as an emulsifier or stabilizer. Compared with the untreated ISF (ISFUT ), superfine grinding reduced the particle size and viscosity of ISF (ISFSG ). Steam explosion increased the water solubility from 17.5% to 51.7% but decreased the water holding capacity and swelling capacity of ISF (ISFSE ) from 15.0 and 14.0 g/g to 4.2 and 3.3 g/g, respectively. Emulsions prepared by ISFUT and ISFSG before or after enzymatic hydrolysis presented large oil droplets and were unstable. Although emulsions prepared by ISFSE after enzymatic hydrolysis (ISFSE-E ) showed flocculation, the volume-weighted average diameter (19.7 μm) were the smallest while the viscosity and viscoelastic modulus were the highest, and exhibited excellent physical stability during storage. ISF obtained by physical and hydrolysis treatment displayed diverging physicochemical properties while ISF prepared by steam explosion-enzymatic hydrolysis presented the best potential to stabilize emulsions. The present study could provide novel information about the utilization of okara by the application of ISF as an emulsifier or stabilizer. © 2023 Society of Chemical Industry.

Characteristics of insoluble soybean fiber (ISF) concentrated emulsions: Effects of pretreatment on ISF and freeze-thaw stability of emulsions.

The properties of emulsions could be affected by the interactions between the components and network stabilization effect, which are commonly adjusted by changes in pH, ionic strength and temperature. In this work, insoluble soybean fiber (ISF) obtained via homogenization after alkaline treatment was pretreated firstly and then resultant emulsions were freeze-thawed. Heating pretreatment reduced droplet size, enhanced viscosity and viscoelasticity as well as subsequent stability of ISF concentrated emulsions, while both acidic pretreatment and salinized pretreatment decreased the viscosity and weakened the stability. Furthermore, ISF emulsions exhibited a good freeze-thaw performance which was further improved by secondary emulsification. Heating promoted the swelling of ISF and strengthened the gel-like structure of emulsions while salinization and acidization weakened the electrostatic interactions and caused the destabilization. These results indicated that pretreatment of ISF significantly influenced the concentrated emulsion properties, providing guidance for the fabrication of concentrated emulsions and related food with designed characteristics.

Preparation and characterization of cellulose nanocrystals with high stability from okara by green solvent pretreatment assisted TEMPO oxidation

Because the traditional preparation methods of cellulose nanocrystals (CNCs) involve chemical pollution issues, in this study, two typical green solvents, alkali/urea solvent (AUS) and deep-eutectic solvent (DES), were used to dissolve insoluble soybean fibers (ISF) extracted from okara and prepare regenerated CNCs (AUS/CNC and DES/CNC), which were further modified by TEMPO oxidation (AUS/T-CNC and DES/T-CNC). The recoveries of AUS and DES were 82.58 % and 84.00 %, respectively. Chemical composition analysis showed high cellulose purity (>95 %) of the regenerated CNCs. FTIR, XRD and 13C NMR analysis indicated the cellulose structure and polymorph of CNCs. Thermal analysis revealed that the maximum degradation peak of regenerated CNC shifted to a lower temperature. AFM revealed that CNCs exhibited rod-like fiber structures, while AUS-pretreated CNCs exhibited some special spherical fibers. TEMPO oxidation showed an enhancement effect on the characteristics of AUS/T-CNC and DES/T-CNC; DES/T-CNC exhibited higher stability and apparent viscosity than AUS/T-CNC. The DES/T-CNC-based cryogel displayed a higher adsorption capacity for anthocyanin (0.40 g/g) and curcumin (1.09 g/g) with good controlled release capacity. These results indicated that green solvent pretreatment-assisted TEMPO oxidation is a new environmentally friendly and low-cost method for the preparation of CNCs and shows excellent potential in the field of drug loading and controlled release.

Stabilization of Emulsions With High Physical Stability Using Ultrasonic Autoclaving Alkaline-Treated Insoluble Soybean Fiber

Stabilization of Emulsions With High Physical Stability Using Ultrasonic Autoclaving Alkaline-Treated Insoluble Soybean Fiber

Hydration effects of insoluble soybean fiber (ISF) on rheological properties and freeze-thaw stability of ISF concentrated emulsions.

Concentrated emulsions have been formulated in many foods. The insoluble soybean fiber (ISF) can be utilized as a particle to stabilize concentrated emulsions. However, the approach to control the rheological properties and stability of the ISF concentrated emulsions is still worth investigating. In this study, alkali-extracted ISF was hydrated by adding sodium chloride or heating and the prepared concentrated emulsions were subjected to freeze-thawing. Compared with the original hydration method, salinization reduced the absolute ζ-potential of the ISF dispersions to 6 mV, resulting in a lower absolute ζ-potential of the concentrated emulsions, which led to a decreased electrostatic repulsion and the largest droplet size, but to the lowest apparent viscosity, viscoelastic modulus, and stability. By contrast, hydration by heating promoted the interparticle interactions, and then a decreased droplet size (54.5 μm) but with a more densely distributed droplets was observed, together with enhanced viscosity and viscoelasticity properties. The fortified network structure improved the stability of the concentrated emulsions both against high-speed centrifugation and long-term storage. Additionally, secondary emulsification after freeze-thaw further improved the performance of the concentrated emulsions. The results suggest that the formation and stability of the concentrated emulsion could be regulated by different hydration methods of particles, which could be adjusted according to the practical applications. © 2023 Society of Chemical Industry.

Acquisition of insoluble soybean fiber with high gelation performance based on structural modifications through pH-shifting during steam-cooking treatment

Utilization of by-products remains a critical technical challenge in the food industry. This work aimed to improve the gelation performance of insoluble soybean fiber (ISF) from okara based on structural modifications via pH-shifting during steam-cooking treatment. Okara was intrinsically compact and tightly aggregated. Its amorphous region was degraded by steam-cooking at pH 3 and inter-molecular H-bonds were reduced, resulting in increased content of cellulose from 37.86 wt% to 43.32 wt% and crystallinity degree from 7.79% to 40.10%. The compact structure of okara was dissociated into flexible fibers by steam-cooking at pH 11, allowing for higher porosity with a specific surface area reaching 1.4428 m2/g. However, there were no significant changes in microstructure except for a decreased particle size as pH approached neutral. The outstanding structure and adsorption capacity of ISF supported the higher gelatin performance. The hydrogels with a self-supporting and dense network structure were observed after continuous stirring from ISF steam-cooked at pH 3, 4, and 11, which was attributed to H-bonds between ISFs, while okara and other ISF suspensions exhibited good fluidity. These findings provide a new method for ISF treated by steam-cooking to enable hydrogel formation for potential applications in reconstituted foods and low-calorie gel systems.

Formation and characterization of oleogels derived from emulsions: Evaluation of polysaccharide ratio and emulsification method

In the present work, highly oil-binding oleogels were fabricated by two polysaccharides (insoluble soybean fiber (ISF) and hydroxypropyl methylcellulose (HPMC)) using an emulsion-templated method. The polysaccharide-based network was developed by oven-drying ISF and HPMC co-stabilized emulsions to obtain the oleogels and two emulsification methods were compared. The aqueous polysaccharide mixtures displayed an increased hydrodynamic diameter but decreased viscosity with increasing proportions of ISF, leading to a reduced interfacial tension. Increased HPMC reduced the droplet size of emulsions while it improved the apparent viscosity and loss modulus. Emulsions prepared by high-pressure homogenization displayed a smaller droplet size and lower viscosity while the oleogels exhibited abundant liquid oil. By contrast, emulsions prepared by high-speed shearing presented a larger droplet size while the oleogels exhibited well-structured semi-solid oil. The oleogels were endowed with stronger gel strength (increased to 184 g and 461 g, respectively) and hardness from increased HPMC, resulting in a decreased oil loss. Increasing the HPMC content contributed to a more compact structure of the oleogels and emulsions whereby emulsions with a too small droplet size were difficult to be fully converted into gel-like semi-solid oil. Results indicate that ISF and HPMC can be applied in structuring oleogels as substitutes for solid fats.

Effect of egg white protein-insoluble soybean fiber interactions on the formation and structural characteristics of low-oil emulsion gels

Emulsion gels with low oil content have attracted increasing interests, and insoluble soybean fibers (ISFs) have been proven to be the potential natural emulsifying stabilizers for emulsion gels. In this work, the structure and characteristics of low-oil emulsion gels stabilized by egg white protein (EWP) and ISF were investigated via tuning interactions between EWP-ISF below, near, or above the isoelectric point (pI) of EWP. EWP was adsorbed onto ISF matrix via electrostatic attraction and hydrogen bonding as EWP-ISF ratio changed from 1:0 to 1:2 below the pI (pH 3.2), resulting in a 3.52 mg/mL decrease in soluble EWP content. EWP-ISF synergistically adsorbed onto the oil-water interface, and the droplets were incorporated into gel matrix via hydrophobic interaction, improving the water-binding capacity and gel structure. The addition of ISF could still improve the gel structure at pH 4.5 despite the weakened interactions of EWP-ISF. However, the competitive adsorption occurred above the pI (pH 7.0), with more ISFs participating in interfacial stabilization; simultaneously the interactions between droplet-gel matrix were weakened, resulting in a decreased gel strength. Overall, ISF improved structural properties of low-oil emulsion gels, which exhibited a higher water-binding capacity and gel strength (14.9 g) at pH 3.2 and EWP-ISF ratio of 1:2.

Dietary Soybean Protein Decreases Plasma Taurine in Cats

Commercial dry and canned diets fed to cats cause ∼two- and fourfold increase in the taurine requirement, respectively, as compared with that observed for purified diets. In two experiments, the effect of source and level of protein and fiber in the diet on the concentration of taurine in plasma and whole blood of cats was studied. All diets contained 1 g taurine/kg dry matter. When a casein-based diet containing either 25% or 50% protein was given to cats for 6 wk, no difference in plasma taurine concentration was observed; however, substituting soybean protein for casein resulted in a significant (P < 0.01) decrease in plasma taurine concentration of cats in the 50% soybean protein group, but not in the 25% soybean protein group. In Experiment 2, the food intake of cats was limited [26 g dry matter/(kg body weight·d)], and the protein was 30 or 60% of the diet. Cats fed 60% soybean protein or casein diets had significantly lower plasma taurine concentrations than cats fed a 30% casein diet, with the 60% soybean protein diet causing the greater decrease. There was no effect of either 2 or 4% soybean fiber on plasma taurine concentration as compared with the same diet without the added fiber. The taurine concentration in plasma was higher (P < 0.05) in male cats than in female cats. Protein source, amount in the diet and gender did not affect the whole blood taurine concentration. Cats given diets containing 60% casein or soybean protein diets excreted a greater amount of fecal total bile acid and total taurine than cats given a 30% casein diet. Cats with higher plasma concentrations of taurine excreted a greater amount of free taurine in urine, and a lesser amount of taurine and bile acids in feces. These results show that although protein source (soybean protein) and the quantity in the diet have a significant effect on the excretion pattern of taurine by cats, these effects are not sufficient to account for the marked increase in the taurine requirement found when canned heat-processed diets are fed.

Effects of microwave on the potential microbiota modulating effects of agro-industrial by-product fibers among different individuals

Microwaving was used to improve the functional properties of dietary fibers. However, the effects of microwave on the fermentability of different fibers and their role in modulating the gut microbiota were not clear. Four agro-industrial by-product fibers were treated with microwave and their fermentability and microbiota-modulating effects on different inoculum sources were investigated. The microwave treated fiber had a looser microscopic structure and more soluble dietary fiber (SDF). Microwave treatment increased soluble fiber the most, short-chain fatty acid production the most, and altered the microbial community the most in soybean fiber, while it caused the least changes in fiber structure and fermentability in sweet potato fiber. Although fecal inocula and fiber source had a greater effect on fiber fermentation, microwave treatment had a small but significant effect on fiber fermentability. Microwave treatment decreased gas production and pH in all four fibers. The key bacteria that responded to microwave treatment were clustered into 25 co-abundance groups (CAGs). CAG10 consisting of Blautia spp. and Bifidobacterium spp. was affected by microwave treatment and positively associated with SDF in all donors. This study showed that the new niches created by microwave, including increased SDF and loosened fiber structure, both contributed to the improvement of the fermentability and microbiota modulating effects of the different fibers.

Preparation and characterization of emulsion gels stabilized by adequately preprocessed insoluble soybean fiber from okara.

Emulsion gels as soft materials were formulated by insoluble soybean fiber (ISF) assembled from okara in this study. Steam explosion on okara (ISFS) transformed the insoluble fiber in the original okara (ISFU) into soluble fiber. Enzymatic hydrolysis led to a lower protein content, smaller particle size and smaller contact angle of ISF. ISFE, which was obtained by enzymatic hydrolysis of ISFU, was not able to produce stable emulsion gels at 0.50 to 1.50 wt% ISF, whereas the ISF after a combined steam explosion-enzymatic hydrolysis treatment (giving rise to ISFSE) stabilized emulsion gels at varying oil volume fractions (φ) from 10 to 50%. The ζ-potential of emulsion gels was around -19 to -26 mV. The droplet size first decreased (from 43.8 μm to 14.8 μm when at φ = 0.3) with increasing ISF content (from 0.25 wt% to 1.25 wt%) and then remained constant, as also seen from the microstructure. The apparent viscosity and viscoelastic properties were strengthened upon increasing both the ISF concentration and oil volume fraction. The protein and soluble fiber contributed to the interfacial activity of ISF while the insoluble fiber played an important role in the gel-like structured network of emulsion gels, making them maintain physical stability during long term storage. These findings could provide novel information about soybean fiber to fabricate soft materials and the utilization of okara at an industrial-scale.

The formation, structural and rheological properties of emulsion gels stabilized by egg white protein-insoluble soybean fiber complex

In this work, the structural and interfacial characteristics of egg white protein-insoluble soybean fiber (EWP-ISF) complex, as well as the effects of the EWP-ISF ratio and oil volume fraction ( φ ) on the formation of emulsion droplet-aggregated gels were investigated. EWP was adsorbed onto the surface of ISF matrix at pH 3.2 via electrostatic and hydrogen-bonding interactions. The contact angle significantly increased from 119.3° to 131.5° ( p < 0.05) as the EWP-ISF ratio changed from 1:0 to 1:2, simultaneously, the adsorption of EWP-ISF complex at the oil-water interface produced a visible interfacial film. At lower φ of 0.2–0.3, as the EWP-ISF ratio decreased from 2:1 to 1:2, the droplets became finer and the gel-like structure was strengthened; additionally, the relaxation time ( T 23 ) significantly decreased from 622.257 ms to 219.639 ms ( p < 0.05), implying the conversion of movable water to bound water. At a higher φ of 0.4–0.5, the droplets were densely packed through bridging flocculation and interactions between droplets and the gel network. Accordingly, the emulsion droplet-aggregated gels stabilized by EWP-ISF presented high elastic modulus and yield stress, as well as excellent thixotropic recovery. • The emulsibility of egg white protein-insoluble soybean fiber (EWP-ISF) was raised. • EWP adsorbed to the ISF surface via electrostatic attraction and hydrogen-bonding. • The adsorption of EWP-ISF at oil-water interface formed a visible interfacial film. • EWP-ISF emulsion gels had higher yield stress and superior thixotropic recovery.

Incorporation of modified okara-derived insoluble soybean fiber into set-type yogurt: Structural architecture, rheological properties and moisture stability

In the present work, modified okara-derived insoluble soybean fiber (ISF) was incorporated into set-type yogurt to investigate its effect on structure, rheological properties and moisture stability. Low concentrations (0.25% and 0.50%, w/v) of ISF induced a more homogeneous network structure with embedded pores or cavities compared to plain set-type yogurt. At high concentrations (0.75%, 1.00% and 1.25%, w/v), a unique structure of ISF attached to aggregated casein micelles was formed. Oscillation time sweep indicated the onset of the casein micelle network appeared earlier as the ISF concentration increased from 0% to 0.50% and then became later as it continued to increase to 1.25%. Rheological measurements showed that the addition of ISF reinforced the structural strength of the yogurt gel to cope with the applied stress, and the consistency index (Pa·sn) fitted by flow curves increased significantly (p < 0.05) from 11.79 to 51.14 at 1.25% ISF addition. Furthermore, the values of the storage modulus and apparent viscosity were dependent on the addition of higher concentrations of ISF, which was related to the viscos and viscoelastic properties of ISF in the aqueous phase. The yogurt gel matrix bound more tightly to water and also exhibited significantly (p < 0.05) higher water holding capacity than the plain yogurt in the case of centrifugation (1000 g, 20 min), up to 84.5%. This study confirms the benefits of ISF in fortifying yogurt and has important implications for the production of the fiber-rich ‘clean label’ set-type yogurt.

Soya ve Pamuklu Örme Kumaşların Seçilen Performans Özelliklerinin Karşılaştırılması Üzerine Deneysel Bir Çalışma

In this study, 100% soybean and 100% cotton suprem and pique knitted fabrics were produced. Quality performance parameters, color fastness and spectrophotometric color results of the knitted fabrics were compared. The aim of the study is to reveal the advantages and weaknesses of soybean knitted fabrics compared to cotton knitted fabrics. When the production and test results are examined, soybean fabrics are softer than cotton fabrics. Knitted pique 100% soybean protein fiber fabrics dimensional change is worse than 100% cotton. Air permeability of fabrics made from soybean fiber is better than cotton fabrics therefore it can be provided thermal comfort conditions. Bursting strength of soybean fabrics is as good as cotton fabrics. In the color fastness tests, the fastness values of the soybean fabrics were found to be high and wet rubbing fastness is good. As a result of this study, it was seen that the color fastness, softness, abrasion resistance, air permeability of the soybean knitted were better than cotton fabrics. Soybean fabrics were found to be more pilling than cotton fabrics. When the results of the research are examined, 100% soybean fabrics can be used instead of cotton fabrics.

Emulsifying and whipping properties of mixing polysaccharide dispersions: effect of ratio between insoluble soybean fiber and hydroxypropyl methylcellulose.

The interactions between various food colloids in different systems (e.g., dispersions, emulsions, creams) have a bearing on the processing and characteristics of food systems. Hydrophilic polysaccharides have been proven to have the potential to fabricate the above systems. In the present work, hydroxypropyl methylcellulose (HPMC) was partially replaced by the insoluble soybean fiber (ISF) extracted from defatted okara to prepare mixing dispersions, oil-in-water emulsions and whipped creams. The presented work showed that as the proportion of ISF increased, the foaming properties of ISF/HPMC dispersions were enhanced, the absolute value of the ζ-potential and the particle size of the emulsions increased, while the heat stability and centrifugal stability first increased and then decreased. Upon whipping, the loss angle (tan δ) decreased first and then increased, while the overrun, foam stability and cream stability, as well as the elastic modulus (G'), presented the opposite trend. These results indicated that an appropriate amount (40-60%) of ISF in the ISF/HPMC systems enhanced the foaming and emulsifying capacities of mixtures and the stability of the resultant emulsion; subsequently, the whipping performance and whipped cream network structure were strengthened, suggesting that ISF has great potential for application in whipped cream as a 'green' and safe food ingredient. © 2022 Society of Chemical Industry.

Hot Air-Assisted Radio Frequency (HARF) Drying on Wild Bitter Gourd Extract.

Wild bitter gourd (Momordica charantia L. var. abbreviata S.) is a kind of Chinese herbal medicine and is also a vegetable and fruit that people eat daily. Wild bitter gourd has many bioactive components, such as saponin, polysaccharide, and protein, and the extract is used to adjust blood sugar in patients with diabetes. The objective of this study was to investigate simultaneous hot air-assisted radio frequency (HARF) drying and pasteurization for bitter gourd extract, and then to evaluate its effects on blood sugar of type II diabetic mice. The results showed that the solid–liquid ratio of the wild bitter gourd powder to water was 1:10 and it was extracted using focused ultrasonic extraction (FUE) for only 10 min with 70 °C water. Then, 1 kg of concentrated bitter gourd extract was mixed with soybean fiber powder at a ratio of 2:1.1. It was dried by HARF, and the temperature of the sample could reach above 80 °C in only 12 min to simultaneously reduce moisture content (wet basis) from 58% to 15% and achieve a pasteurization effect to significantly reduce the total bacterial and mold counts. Type II diabetic mice induced by nicotinamide and streptozocin (STZ) for two weeks and then were fed four-week feeds containing 5% RF-dried wild gourd extract did not raise fasting blood glucose. Therefore, the dried powder of wild bitter gourd extracts by HARF drying had a hypoglycemic effect.

A novel preparation strategy of emulsion gel solely stabilized by alkaline assisted steam-cooking treated insoluble soybean fiber

In this work, the insoluble soybean fiber, which was derived from okara facilely prepared by alkaline assisted steam-cooking treatments (AST-ISF), was used to prepare emulsion gels through regulating oil volume fraction (φ, 0.1–0.6) and ISF concentration (c, 0.05%–0.5%). AST-ISF was mainly composed of insoluble fiber (82.99 ± 0.24%), and most proteins were removed by alkaline treatment. AST endowed ISF with a higher crystallinity index (47.30 ± 0.82%) and moderate interfacial wettability (87.2 ± 1.2°), which facilitated the adsorption of AST-ISF at the oil-water interface and the formation of a stronger gel-like network structure. Raw okara and alkaline treated ISF could not form emulsion gels. In contrast, the emulsion gels could be formed by AST-ISF, and it was enhanced by AST-ISF adsorbing and entrapping with the oil phase. Oil volume fraction was a crucial factor affecting the microstructure. Especially when φ = 0.5, the degree of droplet aggregation was particularly prominent, and the elastic modulus increased up to about ten times compared with that at φ = 0.1. The minimum AST-ISF concentration to form emulsion gel was 0.3%. The study revealed that the structure of AST-ISF stabilized emulsion gel was characterized as a hybrid network structure composed of tightly packed oil droplets with cross-linked ISF in the continuous phase.