Effects Of Soy Protein Isolate Research Articles

Insight of soy protein isolate to decrease the gel properties corn starch based binary system: Rheological and structural investigation

Dysphagia has become a growing concern for elderly individuals, and starch-based gel foods is expected to become one of the foods easy to swallow. This study investigated the effects of soy protein isolate (SPI) on the sol-gel behavior, rheological, structural and gel properties of corn starch (CS). SPI raised the gelatinization temperature but reduced enthalpy values, inhibiting the gelatinization of CS. There was a reduction of rheological properties in CS-SPI system, involving apparent viscosity, modulus, and shear structural recovery properties, while SPI increased the Tan δ, creep-recovery, and thixotropic properties. Structural analysis demonstrated that SPI introduction altered the lamellar structure, increased the relative crystallinity, and decreased the hydrogen bond strength and order degree in CS-SPI gels, forming a weaker gel network. As a result, the texture profiles such as hardness, gumminess, and chewiness were decreased from 308.60 g to 64.98 g, 285.44 g–50.62 g, and 279.66 g–50.15 g, respectively, whereas the gel strength of CS-SPI gel decreased from 123.91 g to 45.78 g. This study provided foundations for the production of gel food suitable for swallowing.

Thermorheological properties and structural characteristics of soy and pumpkin seed protein blends for high-moisture meat analogs

This study explored the effects of soy protein isolate (SPI) and pumpkin seed protein concentrate (PSC) blends on the thermorheological properties and microstructure of high-moisture meat analogs. Using a Discovery Hybrid Rheometer, we observed that increasing PSC content weakened SPI network formation, resulting in decreased gel stability and a more porous, less aligned structure. Microstructural analyses (FE-SEM and FT-IR) revealed a correlation between protein network disruption and increased PSC content. Additionally, higher PSC levels reduced overall bonding (ionic, hydrogen, hydrophobic, disulfide), modifying the texture and softening the gel while retaining solid-like characteristics essential for replicating meat textures. Although full high-moisture extrusion conditions were not replicated, the observed trends offer valuable insights into texture development for meat substitutes. Future research using a closed-system rheometer is required to validate these findings and improve precision.

Effect of Soy Protein Isolate on the Quality Characteristics of Silver Carp Surimi Gel during Cold Storage.

This study mainly investigated the effect of soy protein isolate (SPI) on the gel quality of silver carp surimi under different storage conditions (storage temperatures of 4 °C, -20 °C, and -40 °C, and storage times of 0, 15, and 30 d). The results found that 10% SPI could inhibit the growth of ice crystals, improve the water distribution, enhance the water holding capacity of the gels, and strengthen the interaction between surimi and proteins. Compared to the control group, the composite silver carp surimi gel exhibited superior quality in texture, chemical interactions, and rheological properties during cold storage. Fourier transform infrared spectroscopy revealed an increasing trend in α-helix and β-turn content and a decreasing trend of β-sheet and random coil content. As storage time increased, the gel deterioration during cold storage inhibitory effect of the treatment group was superior to the control group, with the best results observed at -40 °C storage conditions. Overall, SPI was a good choice for maintaining the quality of silver carp surimi gel during cold storage, which could significantly reduce the changes in the textural properties during cold storage with improved water holding capacity.

Production of fresh cheese analogues; the impact of soy protein isolate and oat germ powder

AbstractPlant-based proteins are being rapidly explored in the food industry to produce healthy and nutritious foods. Herein, the effects of soy protein isolate (SPI) ratio to oat germ powder (OGP) (0:0, 3.7: 6.3, 5:5, 0:10, 10:0, and 6.3:3.7%) were studied on the physicochemical, colour, rheological, microbial, antioxidant, and sensory properties of wheyless cheese. The results showed that by increasing SPI and OGP levels, ash, white index value, elastic modulus, and complex viscosity decreased, while pH, fat in dry matter, Chroma, and total colour (ΔE) increased. Also, syneresis was only observed in the control sample and was not observed in other samples. Control sample together with sample containing 10% of OGP showed the highest microbial count (i.e., mesophilic bacteria and yeasts-moulds), while samples containing 10% of SPI showed the lowest microbial count. Furthermore, the growth of both coliform and psychrophilic bacteria in all samples was negligible. Based on the results of sensory evaluation, with increasing SPI and OGP, the sensory evaluation score of samples decreased but they were within the acceptable range. According to the results obtained in this study, the combinations of 5% SPI and 5% OGP or 3.7% SPI and 6.3% OGP are recommended to be used in wheyless cheese production.

Effect of soy protein isolate, egg white protein and whey protein isolate on the flavor characteristics of silver carp (Hypophthalmichthys molitrix) surimi

The objective of this study was to investigate effects of soy protein isolate (SPI), egg white protein (EW) and whey protein isolate (WPI) on flavor characteristics of silver carp surimi. A total 72 volatile odor compounds (VOCs) were identified in surimi gels with non-muscle proteins (NMPs). SPI had significant effects on the VOCs with low thresholds in surimi gels, while EW had relatively lower effect. They all reduced undesirable VOCs, such as nonanal, 1-octen-3-ol. Three proteins reduced fatty acids (FAs) in surimi, while most free amino acids (FAAs) were reduced in surimi with SPI or EW. Most of the VOCs had higher positive correlation with FAAs in surimi with SPI or WPI, but negative correlation with EW. FAs of surimi with SPI were higher than those with EW or WPI, while a few of VOCs (1-octen-3-ol, hexanal and nonanal) had higher correlation with FAs. Three proteins reduced protein and lipid oxidations in surimi gels, while WPI more reduced protein and lipid oxidations. FAAs were main causes of VOC changes in surimi gels with NMPs. Results suggested NMPs could modify the flavor of surimi gels and cover up the fishy odor and 2% or 4% was the appropriate addition of NMPs.

Application of soy protein isolate-xylose conjugates for improving the viability and stability of probiotics microencapsulated by spray drying.

Production and consumption of probiotics need to meet many adverse stresses, which can reduce their health-promoting effects on humans. Microencapsulation is an effective technique to improve the biological activity of probiotics and wall materials are also required during encapsulation. Application of Maillard reaction products (MRPs) in probiotic delivery is increasing. This work aims to study the effects of soy protein isolate (SPI)-xylose conjugates heated at different times on the viability and stability of probiotics. SPI-xylose MRPs formed after heat treatment based on changes in the browning intensity, sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Fourier transform infrared spectroscopy. After heat treatment, α-helix and β-sheet contents of SPI-xylose mixture shifted from 11.3% and 31.3% to 6.4-11.0% and 31.0-36.9%, respectively, and the thermal stability slightly changed. During spray drying, except for MRP240@LAB, probiotic viability was higher in the MRP-based probiotic microcapsules (21.36-25.31%) than in Mix0@LAB (20.17%). MRP-based probiotic microcapsules had smaller particle sizes (431.1-1243.0 nm vs. 7165.0 nm) and greater intestinal digestion tolerance than Mix0@LAB. Moreover, the MRP-based probiotic microcapsules showed better storability than Mix0@LAB and adequate growth and metabolism capacity. SPI-xylose Maillard reaction products are a promising wall material for probiotics microencapsulation, which can improve bacterial survivability during spray drying and enhance bacterial gastrointestinal digestion resistance. This study sheds light on preparing probiotic microcapsules with superior properties by spray drying. © 2023 Society of Chemical Industry.

Optimizing foam quality characteristics of model food using Taguchi‐based fuzzy logic method

AbstractIn this study, the effects of soy protein isolate (SPI) concentration (0%, 50%, and 100%), sonication time (10, 20, and 30 min), and whipping time (5, 10, and 15 min) on the quality characteristics of the model food foam were investigated and optimized. In order to maximize both foaming capacity (FC) and foam stability (FS), it was aimed to select the optimum process parameters using a Taguchi‐based fuzzy logic method (TBFLM). The experiments were performed according to Taguchi L9 (33) orthogonal design, and the effects of process parameters on foam quality characteristics were investigated by analysis of variance. Optimization results revealed that optimum FC and FS values were obtained with 50% SPI, 30 min sonication, and 10 min whipping. SPI concentration was the most effective factor for the responses in Taguchi single‐response optimization. However, the whipping time has the greatest impact on the multiperformance characteristics index, accounting for 78.93% of the contribution to fuzzy logic multiresponse optimization. The verification experiments revealed that the TBFLM is a useful method for improving foam quality characteristics.Practical applicationsFC and FS are the most important properties, which represent the quality characteristics of model food foams. The Taguchi method failed in multiresponse optimization in the model food application. A Taguchi‐based Fuzzy logic optimization method was successfully applied to optimize the quality characteristics of model food foam, and the optimal conditions were determined as soy protein isolate of 50%, sonication time of 30 min, and whipping time of 10 min. The contribution of whipping time to the multiperformance characteristics index was found to be the highest.

Quality Improvement of Green Saba Banana Flour Steamed Cake

Gluten avoidance is becoming a popular diet trend around the world. In this study, green Saba banana flour (GSBF) was used to produce a gluten-free (GF) steamed cake. The effects of soy protein isolate (SPI) (0%, 10%, 15%) and Ovalette (0%, 3.5%, 7%) on the quality of the cake were investigated. Physicochemical properties of the flours were measured. The viscosity and specific gravity of the batters; as well as the specific volume, weight loss and texture profile of the resulting cakes were determined. Sensory evaluation was performed to compare the acceptance of the cake formulations. The macronutrient and resistant starch content of the cakes were determined. The use of an appropriate level of SPI and Ovalette was found to effectively enhance the aeration of the cake batter and improved the specific volume and weight loss of the cake. The presence of Ovalette was essential to soften the texture of the cake. GF cake supplemented with 10% SPI and 3.5% Ovalette obtained the highest sensorial acceptance. The nutritional quality of this sample was significantly improved, whereby it contained higher protein than the gluten-containing counterpart. GSBF also contributed to the high dietary fiber and resistant starch content of the cake.

Evaluation of the effect of soy protein isolate based milk replacer feeding on digestibility of nutrients and haematobiochemical parameters in cross bred calves

A study was conducted in crossbred calves for a period of 90 days to evaluate the effect of soy protein isolate based milk replacer feeding on digestibility of nutrients and haematobiochemical parameters.Twelve,four-day-old crossbred calveswere selected from University Livestock Farm and Fodder Research and Development Scheme (ULF & FRDS), Mannuthy and were allotted to one of the two dietary treatments. The dietary treatments were T1 (Control) fed with whole milk and T2- fed with soy protein isolate based milk replacer (CP-22 per cent) and milk in the ratio 3:1.To all the experimental animals, calf starter (CP-23 per cent) and adlibitum green grass were offered and were fed according to ICAR (2013). Daily record of quantity of feed (calf starter and milk replacer) andgrass given and balance if any were recorded throughout the experimental period. A digestibility trial for five days duration was carried out towards the end of feeding trial by total collection method. The results revealed similar apparent digestibility of nutrients and haematobiochemical parameters for whole milk and milk replacer fed group.

Soy protein compared with whey protein ameliorates insulin resistance by regulating lipid metabolism, AMPK/mTOR pathway and gut microbiota in high-fat diet-fed mice.

The findings of soy protein versus whey protein supplementation on glycemic regulation are inconsistent. The aim of the present study was to investigate the preventive effect of soy protein isolate (SPI) and whey protein isolate (WPI) on a high-fat diet (HFD) induced insulin resistance and its potential molecular mechanisms. Male C57BL/6J mice were randomly divided into seven groups (n = 12): normal control, HFD plus 10% SPI, HFD plus 20% SPI, HFD plus 30% SPI, HFD plus 10% WPI, HFD plus 20% WPI, and HFD plus 30% WPI. After 12 weeks of feeding, compared with the WPI groups, serum concentration of insulin, homeostasis model assessment of insulin resistance (HOMA-IR) and liver weight were significantly lower in the SPI groups. Compared with the WPI groups, the mRNA levels of CD36, SLC27A1, PPARγ and AMPKα were significantly higher, and those of LPL, SREBP1c, FASN and ACC1 were significantly lower in the liver in the SPI groups. In the liver or gastrocnemius muscle, compared with the WPI groups, the mRNA levels of GLUT4, IRS-1, PI3K and AKT were significantly higher, and those of mTOR and S6K1 were significantly lower, and the protein levels of GLUT4, p-AMPKα/AMPKα, p-PI3K/PI3K and p-AKT/AKT were significantly higher, and those of p-IRS-1Ser307/IRS-1, p-mTOR/mTOR and p-S6K1/S6K1 were significantly lower in the SPI groups. The Chao1 and ACE indices were higher, and the relative abundance of Staphylococcus and Weissella was lower in the SPI groups than those in the WPI groups. In conclusion, soy protein was more effective than whey protein in preventing IR in HFD-fed mice by regulating lipid metabolism, the AMPK/mTOR pathway, and gut microbiota.

Producing mixed-soy protein adsorption layers on alginate microgels to controlled-release β-carotene

In this study, the effects of soy protein isolate (SPI) on the morphology, encapsulation efficiency, storage stability, swelling behavior, and in vitro digestion behavior of calcium alginate (CA) microgels were investigated. CA and calcium alginate-SPI (CAS) microgels with encapsulated β-carotene were prepared by extruding a mixture of alginate and SPI using a co-extrusion technique, followed by cross-linking with Ca2+. All microgels exhibited homogeneous sizes and spherical shapes, and CAS microgels showed high levels of protein loading efficiency. The encapsulation efficiency and storage stability of β-carotene within CAS microgels were higher than those within CA microgels. The introduction of SPI into CAS microgels resulted in a higher degree of gel size shrinkage in gastric fluid and a lower degree of swelling in intestinal fluid compared to CA microgels. In vitro digestion was conducted to investigate the effects of the addition of SPI on the release behavior of CA and CAS microgels. Results obtained showed that CAS microgels were more resistant to simulated gastric fluid than CA microgels. Cryo-scanning electron microscopy (cryo-SEM) and confocal laser scanning microscopy (CLSM) observations indicated that the release behavior was dependent on the porosity of the CA and CAS microgels, and the porosity was influenced by the concentration of SPI. This study showed that the introduction of SPI to CA microgels can lead to the development of an effective controlled release delivery system.

Effect of soy protein isolate on physical properties of quinoa dough and gluten-free bread quality characteristics.

Quinoa is a good gluten-free resource for food processing, especially bread making, and can improve and prevent the development of complications associated with celiac disease (CD). However, lack of gluten affects quinoa bread quality. Previous research showed that soy protein isolate (SPI) could improve gluten-free bread quality to some extent. Therefore, this study investigated the effects of SPI on the physical properties of quinoa dough and gluten-free bread quality characteristics. Results showed that, with appropriate SPI substitution, the farinograph properties of quinoa flour significantly improved (P < 0.05). The sample with 8% SPI substitution showed a better development time (DT, 3.30 ± 0.20 min), stability time (ST, 8.80 ± 0.10min) and softening degree (SD, 8.80 ± 0.10 FU), which were close to those of wheat flour, although more water absorption (WA, 76.40 ± 2.10%) was needed than for wheat flour (66.30 ± 3.10%). The extensograph properties of quinoa flour also significantly improved after 8% SPI substitution (P < 0.05). Furthermore, SPI substitution increased G' moduli of quinoa dough and decreased tan δ to some extent, providing better rheological properties closer to those of wheat dough. SPI substitution also improved the quality and texture of quinoa bread and reduced the gap with wheat bread. When SPI substitution was 8%, the specific volume, hardness and springiness of quinoa bread were 2.29 ± 0.05 mL g-1 , 1496.47 ± 85.21 g and 0.71 ± 0.03%, respectively. These results suggested that SPI substitution would be an effective way to develop higher-quality gluten-free bread. © 2022 Society of Chemical Industry.

Effects of soy protein isolate and soy peptide preload on gastric emptying rate and postprandial glycemic control in healthy humans

BackgroundThis study aims to compare the effects of soy protein isolate (SPI) and soy peptide (PEP) preload 30 min before a 75-g oral glucose tolerance test (OGTT) on the gastric emptying rate, plasma insulin, and blood glucose responses.MethodsNine healthy young subjects were evaluated on four occasions. The participants consumed a 200-ml solution containing either 20 g of SPI or PEP in experiment 1. In experiment 2, 30 min after consuming either 20 g of SPI or PEP solutions, an OGTT was performed to evaluate the individual glycemic response. The gastric emptying rate was measured by the 13C-sodium acetate breath test. Blood glucose and plasma insulin were measured before and after consuming either the SPI or PEP solutions and during the OGTT.ResultsIn experiment 1, plasma insulin levels were higher 30 min after consuming the PEP solution than after the SPI solution. PEP resulted in a faster gastric emptying rate than SPI. In experiment 2, just before performing the OGTT, the plasma insulin response was higher for PEP than for SPI. Fifteen minutes after starting the OGTT, the blood glucose response was lower after consuming PEP than after SPI. The gastric emptying rate tended to be faster after consuming PEP than after SPI (p = 0.08).ConclusionA PEP preload might be slightly more effective for the suppression of postprandial blood glucose excursion compared with SPI; thus, a PEP preload potentially induces an enhanced insulin response just before the OGTT.

Comparing the effect of soy protein isolate coating with sodium and calcium alginate polysaccharide coatings on the oil absorption of eggplant slices during frying

Comparing the effect of soy protein isolate coating with sodium and calcium alginate polysaccharide coatings on the oil absorption of eggplant slices during frying

Effects of Soy Protein Isolate and Inulin on Physico-chemical and Organoleptic Qualities of Low-fat Duck Meat Sausages

Background: The present work was conducted to study the effect of incorporation of soy protein isolate (SPI) and Inulin (I) on certain Physico-chemical and sensory qualities of low-fat duck meat sausages. Methods: Duck meat sausages were prepared by using three different formulations i.e. T1 (2.5% I), T2 (2.5% SPI) and T3 (2.5% SPI+2.5% I) along with a control (CT-0% SPI and I). The pH, water holding capacity, TBARS value, tyrosine value and sensory qualities were evaluated on days 1, 5 and 10. Result: Duck meat sausages with a combination of 2.5% soy protein isolate and 2.5% inulin were the best ones, with a shelf-life of 10 days under refrigeration.

Characterization of emulsion films prepared from soy protein isolate at different preheating temperatures

The effect of soy protein isolate (SPI) preheating temperature on the physicochemical properties of SPI-oil emulsion (SPI-OE) films was investigated. Tensile strength (TS) and elongation at break (EAB) of the SPI-OE films prepared from SPI preheated at 45 °C were 7.90 MPa and 59.30%, respectively. The TS of the SPI-OE films increased with the preheating temperature of SPI, whereas the EAB first increased and then decreased. Discrepancy between the contact angles in the upper and lower surfaces of the films gradually increased with preheating temperature. When the preheating temperature of SPI was higher than 75 °C, oil droplets accumulated on the upper surfaces of the SPI-OE films, as shown in the scanning electron micrographs, and the intensity of absorption peak (1744 cm−1) obtained through infrared spectroscopy decreased. No obvious change in protein molecular weight was found in the SPI-OE films with increasing preheating temperature, but the glass transition temperature increased.

Physicochemical and rheological properties of cooked extruded reformed rice with added protein or fiber

The effect of soy protein isolate (SPI) and dietary fibers [maize bran (MB), resistant maltodextrin (RMD)] on cooked extruded rice quality-related parameters and relating rheology to the human gastric emptying measurement of Lag phase were investigated. DSC onset temperature (To) and peak temperature (Tp) of extruded rice substituted with 20 % SPI (20SPI-ER) were higher than of extruded rice substituted with 20 % MB (20MB-ER) and substituted with 20 % RMD (20RMD-ER). Peak viscosity of 20SPI-ER was lower than that of 20MB-ER and 20RMD-ER, indicating that SPI delayed starch gelatinization. Hardness and stickiness values of cooked 20SPI-ER were significantly higher than those of the control, 20MB-ER, and 20RMD-ER. Storage modulus (G′) value of cooked 20SPI-ER was also higher than the control. It is possible that the swelling of starch granules was decreased when 20%SPI was supplemented. For human gastric emptying, cooked 20SPI-ER resulted in the highest lag phase, indicating that the time of grinding and mixing in the stomach took longer for this reformed rice. Overall the soy-containing cooked extruded rices were somewhat harder than the fiber-containing rices, which may not be as appealing to consumers, though they had a slightly longer Lag phase in the stomach which could relate feeling of fullness.

Effect of Soy Protein Isolate on Textural Properties, Cooking Properties and Flavor of Whole-Grain Flat Rice Noodles.

To investigate the effect of soy protein isolate on the quality of whole-grain flat rice noodles, the texture as well as the cooking properties and flavor of flat rice noodles, whole-grain flat rice noodles and whole-grain flat rice noodles with soy protein isolate were investigated. Among the three tested rice noodles, whole-grain flat rice noodles with soy protein isolate showed the highest cohesiveness, adhesiveness, resilience, and springiness. Compared to the flat rice noodles and whole-grain flat rice noodles, whole-grain flat rice noodles with soy protein isolate increased their moisture content and water absorption, whereas the opposite trend was observed for their cooking loss. The electronic nose analysis showed stronger response values at W5S, W1W, and W2W. Solid phase micro extraction and gas chromatography–mass spectrometry results showed that aldehydes are the main volatile compounds in whole-grain flat rice noodles and whole-grain flat rice noodles with soy protein isolate. Moreover, seven more volatile compounds were detected in whole-grain flat rice noodles with soy protein isolate compared to flat rice noodles and whole-grain flat rice noodles. The whole-grain flat noodles with the addition of SPI are more sensory acceptable. Thus, soy protein isolate, as a natural and safe additive, could be used to improve the quality and enrich the flavor of whole-grain flat rice noodles.

Effects of soy protein isolate on mechanical and hydrophobic properties of oxidized corn starch film

Oxidized corn starch (OS) has a good film-forming ability; however, its poor mechanical properties and moisture barrier are shortcomings. To improve the deficiencies of OS film, soy protein isolate (SPI) with different ratios (10%, 20%, and 30%) was incorporated into OS film at different pH values (6, 8, and 10) to investigate the mechanical and hydrophobic properties of the blended films. The blended films were characterized by water sensitivity, contact angle, mechanical properties, optical properties, and microstructure. The increases in the SPI ratio and pH reduced the moisture content and total soluble matter of the blended films. The reduction in water vapor permeability and the increase in contact angle from 37.3° to 104.5° suggested that the moisture barrier of the OS film was improved by SPI. The elongation at break of blended films increased, but the tensile strength decreased with increasing of SPI content and pH. The blended films prepared at pH 10 were more yellow and had higher transmittance. Scanning electron microscopy and atomic force microscopy showed that the blended films exhibited denser microstructures and smoother surfaces with the increasing pH. X-ray diffraction and thermogravimetric analysis implied that SPI interfered with the intermolecular interaction of OS.

Effects of soy protein isolate on gel properties and water holding capacity of low-salt pork myofibrillar protein under high pressure processing

This paper studies the effects of soy protein isolate (SPI; 0, 2% and 4%; Weight/Weight) on texture, rheological property, sulfhydryl groups, and the water distribution state of low-salt (1% NaCl) pork myofibrillar protein systems under high pressure processing (HPP, 200 MPa, 10 min). The L⁎ value, cooking yield, hardness, total and reactive sulfhydryl, surface hydrophobicity, and the G' value at 80 °C of pork myofibrillar protein increased significantly (P < 0.05) when SPI was added; however, the springiness, cohesiveness, and chewiness of gels with 4% SPI were lower than of gels with 2% SPI. The rheological findings indicated that the thermal stability of the myofibrillar protein increased when SPI was added. The initial relaxation time of T2b, T21, and T22 decreased when SPI increased; meanwhile, the peak ratio of P21 increased significantly (P < 0.05), implying that water had lower mobility. Overall, the 2% SPI could enhance gel characteristics and water-holding capacity of pork myofibrillar protein under 200 MPa.