Soybean Protein Research Articles

Conferring non-strain-specific resistance to a potyvirus via overexpression of mutant potyviral coat proteins in soybean.

Transgenic soybean (Glycine max) plants expressing mutant potyviral coat proteins that disrupt virion assembly exhibited non-strain-specific resistance against soybean mosaic virus.

Genome-Wide Identification, Expression and Interaction Analysis of GLN Gene Family in Soybean

As a globally significant economic crop, the seed size of soybean (Glycine max [L.] Merr.) is jointly regulated by internal genetic factors and external environmental signals. This study discovered that the GLN family proteins in soybean are similar to the KIX-PPD-MYC transcriptional repressor complex in Arabidopsis, potentially influencing seed size by regulating the expression of the downstream gene GIF1. Additionally, β-1,3-glucanase (βGlu) plays a crucial role in antifungal activity, cell composition, flower development, pollen development, abiotic resistance, seed germination, and maturation in soybean. Through a detailed analysis of the structure, chromosomal localization, phylogenetic relationships, and expression situations in different tissues at different stages of the soybean GLN gene family members, this research certifies a theoretical foundation for subsequent research on the biological functions of GLN genes in soybean. This research incorporated a comprehensive genomic identification and expression analysis of the GLN gene family in soybean. The results indicate that the 109 soybean GLN genes are unevenly distributed across soybean chromosomes and exhibit diverse expression patterns in different tissues, suggesting they may have distinct functions in soybean morphogenesis. GO enrichment analysis shows that the GLN gene family may participate in a variety of biological activities, cellular components, and molecular biological processes, particularly in catalytic activity, cellular components, and metabolic processes. These findings provide important information for comprehending the role of the GLN gene family in soybean and offer potential targets for molecular breeding of soybean.

In vitro simulated digestion and Caco-2 cell absorption to explore potential of soy protein isolates as whey protein substitutes in canine and feline food.

Digestive properties and bioavailability of soy protein isolate and whey protein in canine and feline were evaluated using in vitro simulated digestion and cell absorption experiments. The amino acids and peptides in soybean protein isolate and whey protein after digestion were detected by high-performance liquid chromatography and liquid mass spectrometry. Gastrointestinal digestion rates of soy protein isolate and whey protein were analyzed by fitting digestive kinetics curves. The degree of absorption and utilization of amino acids and peptides from the digestive products was evaluated by establishing a Caco-2 cell model. The results demonstrated that soy protein isolate, like whey protein, could produce large amounts of free amino acids and peptides distributed 100-1500 Da. The gastrointestinal digestion speed of soy protein isolate was similar with whey protein. It is worth noting from the intestinal absorption of Caco-2 cell that more than 15 amino acids produced by soy protein isolate and whey protein could be absorbed, and a large number of peptides were also utilized by Caco-2 cell. The bioavailability of soy protein isolates and whey protein for dogs respectively reached 6.30% and 9.00%, and it reached 7.40% and 16.40% in cats, respectively. Soy isolate proteins can be digested and absorbed by pets like whey proteins. These findings may provide significant strategies and support for the application of plant-based proteins in pet foods.

Opportunities and challenges of plant proteins as functional ingredients for food production

Consumer interest in meat and dairy alternatives drives demand for plant-based protein ingredients. While soy and gluten dominate the market, there is a trend to explore alternative crops for functional ingredient production. The multitude of ingredients poses challenges for food manufacturers in selecting the right protein. We investigated 61 commercially available protein ingredients from various sources, categorizing them based on their protein content into protein-rich flours (protein content less than 50%), protein concentrates (protein content between 50% and 80%), and protein isolates (protein content higher than 80%). Methionine, cysteine, and lysine were decisive for the amino acid score, which even varied between ingredients produced from the same raw material. Such differences were also observed in the protein solubility profiles, characterized by their raw material-specific protein pattern. By focusing on soy, pea, and fava bean ingredients, the broad spectra of emulsifying and foaming properties were illustrated. These ranged from non-emulsifying and non-foaming to high emulsifying capacities of 737 mL/g ingredient and foaming activities of 2,278%, accompanied by a foam stability of 100%. Additionally, we demonstrated that the functionality of ingredients obtained from different batches could vary by up to 24% relative SD. Protein solubility, powder wettability, color, and particle size were determined as key properties for the differentiation of soy, pea, and fava bean protein ingredients by principal component analysis. In our study conclusion, we propose essential measures for overcoming challenges in protein ingredient production and utilization to realize their full potential in fostering sustainable and innovative plant-based food production.

Development and Characterization of an Environmentally Friendly Soy Protein-Modified Phenol–Formaldehyde Resin for Plywood Manufacturing

Most wood-based panels were currently prepared using aldehyde-based adhesives, making the development of natural, renewable, and eco-friendly biomass-based adhesives a prominent area of research. Herein, the phenolic resin was modified using a soybean protein isolate (SPI) treated with a NaOH/urea solution through a copolymerization method. The physicochemical properties, chemical structure, bonding properties, and thermal properties of the soybean protein-modified phenolic resin (SPF-U) were analyzed using Fourier transform infrared spectroscopy, thermogravimetric analysis, and formaldehyde emission tests. The results indicated that the molecular structure of the soy protein isolate degraded after NaOH/urea solution treatment, while the gel time was gradually shortened with increasing NaOH/urea solution-treated soy protein isolate (SPI-U) dosages. Although the thermal stability of the soy protein isolate was lower than that of the phenolic resin, the 20% SPF-U resin demonstrated better thermal stability than other modified resins. The PF modified with 30% SPI-U (SPF-U-3) exhibited the lowest curing peak temperature of 139.69 °C than that of the control PF resin. In addition, all modified PF resins exhibited formaldehyde emissions ranging from 0.18 to 0.38 mg/L when the SPI-U dosage varied between 20% and 50%, thereby meeting the E0 plywood grade standard (≤0.5 mg/L).

A comparative study of different soybean oil forms on the physicochemical properties of surimi myofibrillar protein gel: The role of soybean protein isolate and κ-carrageenan

Natural soybean oil, Pickering emulsion, high-internal-phase emulsion (HIPE), and emulsion gel were prepared to investigate their effects on the physicochemical properties of surimi myofibrillar protein gels. Their effects on gel strength ranked as: emulsion gel > Pickering emulsion > HIPE > soybean oil. At the same oil content, the emulsion gel exhibited higher G' than the other forms whereas natural oil exhibited the lowest G', and T22 was smaller in the emulsion gel group, indicating that the emulsion gel enhanced the interaction between water molecules and protein macromolecules. FT-IR testified that 9 % natural oil reduced the β-sheet content to 26.34 %, whereas Pickering emulsion, HIPE, and emulsion gel recovered the β-sheet content to 31.30 %, 36.17 %, and 32.69 %, respectively. Emulsion gel led to fewer voids, and the oil droplets in emulsion gel were more regularly spherical and homogeneously dispersed in the gel matrix, which might be attributed to the filling effects as well as “bridging action” of soybean protein isolate and κ-carrageenan within surimi proteins. In conclusion, we demonstrated emulsion gel as a good replacer to mitigate the negative effect of oil on the texture and structure of surimi gels, which would be a promising approach for oil supplementation in surimi production.

Novel decision-level fusion strategies combined with hyperspectral imaging for the detection of soybean protein content

Novel decision-level fusion strategies combined with hyperspectral imaging for the detection of soybean protein content

Effects of salt ions and pH on deaminated soybean protein hydrogels formation: Molecular structure, thermal aggregation and network

Effects of salt ions and pH on deaminated soybean protein hydrogels formation: Molecular structure, thermal aggregation and network

Inclusion of Tenebrio molitor larvae meal in the diet of barbary partridge (Alectoris barbara) improves caecal bacterial diversity and composition

In this study, we investigated the influence of the inclusion of Tenebrio molitor (TM) larvae meal in the diet on the diversity and structure of the bacterial community in the caecal content of Barbary partridges. A total of 36 partridges, selected randomly for slaughter from 54 animals, were divided equally into three treatment groups, including the control group (C) with a diet containing corn-soybean meal and two experimental groups, in which 25% (TM25) and 50% (TM50) of the soybean meal protein was replaced by the meal from TM larvae. After slaughtering, the bacterial community of the 30 caecal samples (10 samples per each experimental group) was analysed by high-throughput sequencing using the V4–V5 region of the 16 S rRNA gene. Alpha diversity showed a higher diversity richness in the TM50 group. Beta diversity showed statistical dissimilarities among the three groups. Firmicutes was the dominant phylum regardless of the diet, with the predominant families Ruminococcaceae and Lachnospiraceae. Clostridia and Faecalibacterium were decreased in both TM groups, Lachnospiraceae was suppressed in the TM50 group, but still this class, genus and family were abundantly present in all samples. Several potentially beneficial genera, such as Bacillus, Ruminococcaceae UCG-009, Oscillibacter and UC1-2E3 (Lachnospiraceae) were increased in the TM50 group. The results showed a beneficial effect of the T. molitor larvae meal on the caecal microbiota of Barbary partridges, particularly in the TM50 group, which showed an increase in bacterial diversity.

Unlocking curcumin's revolutionary: Improvement of stability and elderly digestion by soybean oil bodies and soybean protein-chitosan complex based Pickering emulsion

Curcumin shows promise for disease prevention and health improvement, but its limited water solubility and vulnerability to degradation reduce its bioavailability, while its biological fate in elderly is unclear. Oil bodies are natural pre-emulsified oil droplets that serve as carriers for functional nutrients. In this study, soybean protein isolate (SPI) was complexed with chitosan (CS) for the purpose of stabilizing the soybean oil body-curcumin emulsion, resulting in the formation of the soybean isolate protein-chitosan-soybean oil bodies-curcumin Pickering emulsion (SPI-CS-SOB-C). The study examined the digestive properties, bioaccessibility of curcumin, free fatty acids (FFA) release, and microstructure changes of SPI-CS-SOB-C through an in vitro elderly digestion model. The findings indicated that curcumin was effectively encapsulated within the SPI-CS-SOB-C, achieving an encapsulation efficiency of 97.7 %, which resulted in notable enhancements in light, heat, and storage stability, as well as an extended half-life of curcumin to 85 months. In vitro elderly digestion demonstrated that SPI-CS-SOB-C notably enhanced the bioaccessibility of curcumin, increasing it from 14.3 % to 51 %. The low FFA release of SPI-CS-SOB-C (23.06 %) suggested its potential suitability for incorporation into low-fat food products and using in food products for the elderly. The results of this study could offer theoretical insights for the utilization of oil bodies in food applications and the delivery of functional nutrients.

Snail mucus-inspired soybean meal adhesive with excellent mechanical strength and prepressing performance

Plant-derived soybean protein adhesives have potential to replace petroleum-based resins. However, soybean protein adhesives generally face a compromise between bonding strength and toughness, and these adhesives display insufficient prepressing strength, hindering their further industrial application. Herein, inspired by the interface drainage snail mucus, we integrated electrostatic interaction and hydrogen bonding into adhesive network to achieve excellent mechanical strength and prepressing performance. Specifically, oppositely charged phytic acid functionalized boron nitride nanosheets (PA@BNNSs) and quaternized chitosan (QCS) formulated with soybean meal (SM) to produce the biomimetic adhesive. The electrostatic interaction formed between PA@BNNSs and QCS serves to enhance the cohesive strength of the adhesive in the wet state, while also improving its wettability. Benefiting from multiple interactions and nanomaterial reinforcement, the biomimetic adhesive achieved a prepressing strength of 0.65 MPa and wet shear strength of 2.53/1.50 MPa, which were 124 % and 80.7/117 % higher than the pure SM adhesive. In addition, the biomimetic adhesive exhibited good flame-retardant and mildew resistance properties. Therefore, this work offers a route to prepare advanced multifunctional bio-based adhesives.

Soybean Oil and Protein: Biosynthesis, Regulation and Strategies for Genetic Improvement.

Soybean (Glycine max [L.] Merr.) is one of the world's most important sources of oil and vegetable protein. Much of the energy required for germination and early growth of soybean seeds is stored in fatty acids, mainly as triacylglycerols (TAGs), and the main seed storage proteins are β-conglycinin (7S) and glycinin (11S). Recent research advances have deepened our understanding of the biosynthetic pathways and transcriptional regulatory networks that control fatty acid and protein synthesis in organelles such as the plastid, ribosome and endoplasmic reticulum. Here, we review the composition and biosynthetic pathways of soybean oils and proteins, summarizing the key enzymes and transcription factors that have recently been shown to regulate oil and protein synthesis/metabolism. We then discuss the newest genomic strategies for manipulating these genes to increase the food value of soybeans, highlighting important priorities for future research and genetic improvement of this staple crop.

Mechanism of targeted uric acid reduction by soybean protein peptide SHECN in hyperuricemia mice and improvement of liver injury

Hyperuricemia (HUA) is a chronic condition characterized by abnormal purine metabolism. SHECN (Ser-His-Glus-Cys-Asn), a soy-derived peptide, has demonstrated uric acid (UA) lowering and antioxidant properties in vitro. The aim of this study was to further explore its uric acid lowering potential in hyperuricemia mice. The results indicated that UA level in SHECN-H group (40 mg/kg) was reduced to 32.80 ± 1.23 μmol/L compared with that in HUA group (104.46 ± 7.30 μmol/L). SHECN group decreased serum xanthine oxidase (XO) and adenosine deaminase (ADA) activities, AST and ALT activities. Additionally, SHECN significantly ameliorated fiber damage observed in mouse liver tissue. We also found that under the action of SHECN, the active expression of XO and ADA in serum and liver was down-regulated, and the expression of hypoxanthine-guanine phosphoribosyl transferase (HGPRT) was up-regulated. Notably, SHECN effectively mimics interactions with XO-associated target proteins as well as key liver transporter receptor proteins. This study further confirmed that SHECN can affect the activity level of the key receptor protein of uric acid synthesis in the liver of mice, and ultimately reduce the serum uric acid level and alleviate liver injury (P < 0.05).

Uncovering key genes associated with protein and oil in soybeans based on transcriptomics and proteomics

Soybean is an important oilseed crop, providing abundant protein and fat for human consumption. However, in practical production, there exists a significant negative correlation between soybean oil and protein content, making it difficult to obtain soybean varieties with both high protein and high oil content. There is limited research on the regulatory network governing soybean oil and protein content. We selected four soybean varieties, Sui Xiao Li (SXL), Ji Da 5 (JD5), Ji Da 33 (JD33), and Ji Yu 202 (JY202), and determined their protein and oil content. We found that SXL and JD33 are high-protein, low-oil varieties, while JD5 and JY202 are high-oil, low-protein varieties. Subsequently, transcriptomic and proteomic analyses were conducted on these four soybean varieties. The results revealed a total of 7182 differentially expressed genes (DEGs) and 1037 differentially expressed proteins (DAPs) among the four soybean varieties SXL, JD5, JD33, and JY202. Through KEGG analysis, we identified 96 and 319 DEGs involved in fatty acid metabolism and protein metabolism, respectively, as well as 23 and 28 DAPs involved in fatty acid metabolism and protein metabolism, respectively. Additionally, based on WGCNA and PPI interaction networks, several central genes were identified, which potentially play a role in the accumulation of protein content and oil content. These potential genes mainly participate in processes such as glycolysis and carbon metabolism. Joint analysis of transcriptomic and proteomic data revealed generally poor correlation between gene expression at the transcriptional and protein levels, with 240 co-regulated genes identified. Combining metabolic pathways, we identified 12 and 5 genes that are involved in lipid metabolism and protein synthesis at both transcriptional and translational levels, respectively. Finally, based on predictions of correlation and interaction, we identified 22 genes that may simultaneously regulate protein and oil content negatively at the transcriptional and translational levels. This study provides important scientific guidance for the genetic improvement of soybean quality components.

High-pressure homogenization assisted pH-shifting modified soybean lipophilic protein interacting with chitosan hydrochloride: Double emulsion construction, physicochemical properties, stability, and in vitro digestion analysis

This study was aimed to improve ability of soybean lipophilic protein (LP) to stabilize W/O/W emulsions. LP modified through high-pressure homogenization assisted pH-shifting, then modified LP-chitosan hydrochloride (MLP-CHC) complexes were prepared, which used stabilize W/O/W emulsions. Multispectral techniques unveiled that high-pressure homogenization assisted pH-shifting attenuated vibrational frequency of N-H in LP and expose more hydrophobic residues. According to molecular docking, MLP and CHC formed covalent complexes through electrostatic attraction and improved ability to stabilize the interface. The W/O/W emulsion using high-pressure homogenization assisted base-shifting LP (11LP) had a smaller particle size (9.96 μm), higher absolute potential (46.96 mV) and interfacial adsorbed protein (67.02%). Meanwhile, MLP-CHC complexes allowed the W/O/W emulsion to form stronger network structure and exhibit stronger stability in acidic, alkaline, thermal and high ionic concentration environments. The in vitro digestion showed that W/O/W emulsion could effectively protect the bioactivity of vitamin B12 and vitamin E during the digestion process, and realize their efficient delivery. This study offers theoretical reference for constructing of protein-polysaccharide-based functional emulsion transport systems for food industry.

Glycine soja, PI424025, is a valuable genetic resource to improve soybean seed-protein content and composition.

Soybean seed-protein content and composition is important because it contributes over half the value of this $61 billion crop. Historic negative correlation between seed-protein content and oil have been reported. Similarly, negative correlation between seed-protein content and yield have been reported but may be at least in part mitigated by increasing the genetic diversity of the elite soybean germplasm. Improvements in amino acid composition of seed-protein would increase the value of soybean meal and protein for animal and human consumption. We have identified a genetic resource in wild soybean germplasm, PI424025B, with elevated seed-protein, elevated cysteine in the seed and increased sulfur content in the seed. We have developed a population of Recombinant Inbred Lines derived from a cross between NC-Raleigh and PI424025B. We evaluated the carbon, nitrogen and sulfur (C, N and S) content of seeds from the progeny, the parents and other high-seed protein soybean lines. N content and C/N (ratio of C to N) were well correlated with protein content measured by NIR. PI424025B had a N content comparable to high-protein soybean lines and a superior N/S. These traits were inherited by some of the progeny. Quantitative Trait Loci (QTL) associated with high-seed protein were identified on chr2, chr20 and chr15 and colocalizes with well characterized loci on chr 15 and chr 20 known to affect seed-protein content and quality. A potentially unique QTL was identified on Chr15. Unlike the chr20 QTL, the chr15 QTL improved S content relative to N content and was superior to other high seed-protein phenotypes tested. These data indicate that PI424025B is a valuable resource to diversify the genetics of soybean while improving soybean seed-protein content and composition.

Effect of oil and particles content on microstructure, rheology, and thermosensitive 3D printability of particles -stabilized high internal phase Pickering emulsions

In this study, soybean protein isolate (SPI) microgel/chitosan (CS) blending system prepared by gel fragmentation were used as particle-based emulsifiers. The presence of chitosan significantly reduced the particle size of the particles and decreased their contact angle (from 129° to 102°), thereby enhancing their wettability. These particles adsorbed onto the oil-water interface by rapidly decreasing the interfacial tension, forming stable O/W-type high internal phase Pickering emulsions. Confocal laser scanning microscopy analysis showed that the droplets were tightly packed together, and some of them were observed to have a polyhedral shape due to the packing, which is the basis for the formation of self-supporting structures. The rheological properties are closely related to the 3D printing results, increasing the oil and particles concentration improves the viscosity, energy storage modulus and gel strength of the system, while the excellent thixotropy facilitates the ability to 3D print these emulsions. At an oil content of 75% and a particles concentration of 3.0%, the accuracy and stability of the printed models were 97.9% and 99.2%, respectively. Introduction of curcumin and NaHCO3 led to a color change from yellow to reddish-brown during heating, enabling thermosensitive 3D printing of color changing HIPPEs. This study may broaden the range of applications of plant-based HIPPEs in 3D and thermosensitive 3D printing, as well as for the development of other innovative food products.

Effect of limited hydrolysis on the structure and gel properties of soybean isolate proteins: A comparative study of papain or/and trypsin

Plant protein's gelation is crucial in various food applications, and hydrolysis may enhance their gelation properties. In this study, we prepared soybean protein isolate hydrolysates (SPIH) using trypsin and/or papain, and found significant improvement in the solubility and gelling properties. These proteases broken down the peptide bonds and caused the exposure of hydrophobic groups as well as the unfolding of protein. Low molecular weight (<35 kDa) SPIHs were generated by the two-step enzymatic hydrolysis, showing significant improvements in storage modulus (G′), loss modulus (G″), viscosity, strength, and water-holding capacity (WHC). Among, PT-10 exhibited the highest WHC (61.72 ± 0.36 %), gel strength (4.67 ± 0.12 g), and network cross-linking density (0.33 ± 0.01 mol/m3), while its solubility was also significantly increased up to 254 %. According to the results of gel molecular force interactions, disulfide bonds, hydrophobic interactions and hydrogen bonds involved in the gel network formation. These findings reveal that the appropriate hydrolysis modification may improve SPI gel's properties and expand its application in gel foods.

Conformational and processing properties of a high-active ingredient involving soy protein isolates bound with anthocyanins and its application in cake baking

Soybean protein is of plant origin and is commonly appropriate for improving the processing characteristics of foods. This study aimed to explore a novel functional ingredient that contained soybean protein isolate (SPI) and blueberry anthocyanins (BANs). The spatial conformation and secondary structure of SPI-BANs complexes were analyzed using circular dichroism and fluorescence spectroscopy, the processing properties were investigated as well as the retention of antioxidant activity during thermal treatments. Results showed that the contents of free sulfhydryl and free amino groups in complexes increased to 3.50 and 1.19 folds than those of SPI, respectively, while the surface hydrophobicity decreased by 74.23%. Compared with SPI, the BANs-modified SPI had a smaller particle size of 29.12 nm and a lower zeta-potential of -8.73 mV and on the other hand, the complexes possessed higher solubility (83.08%) and foaming and emulsifying properties (115.08% and 54.03 m2/g). After fortification with SPI-BANs, the baking loss rate and adhesiveness of chiffon cake were reduced by 10.82% and improved to 0.24 N.mm, respectively. The high antioxidant activities of SPI-BANs under heat led to the cake’s bioactivities largely enhanced by 1.99 ~ 12.71 folds, being 345.19 µg Trolox/g for the DPPH radical scavenging activity. This study developed the functional food ingredients as antioxidants and a substitute for animal-based proteins in bakery products, which was safe and sustainable by using the dietary components from plant resources.Graphical

Using Egg Parasitoids to Manage Caterpillars in Soybean and Maize: Benefits, Challenges, and Major Recommendations.

The use of egg parasitoids in Augmentative Biological Control (ABC) is a highly effective strategy within the integrated pest management (IPM) of lepidopteran defoliators. Safer than chemical insecticides, these natural antagonists have demonstrated significant efficacy. Trichogramma pretiosum and Telenomus remus, known for their high parasitism rates, are the most extensively used and studied parasitoids for controlling economically important lepidopterous in crops such as soybean and maize. Brazil, a leading adopter of crops expressing Bacillus thuringiensis (Bt) proteins, faces growing field-evolved resistance to Cry proteins in soybean and maize. This resistance, particularly of Rachiplusia nu in soybean and Spodoptera frugiperda in maize, has become more prominent in recent years, increasing insecticide use. Therefore, this article reviews the current status of egg parasitoids adoption in ABC against lepidopteran pests, emphasizing the role of Tr. pretiosum and the potential of Te. remus as sustainable alternatives to chemical insecticides to manage pests in both non-Bt and Bt crops. Additionally, we provide recommendations for using these parasitoids in ABC programs and discuss the challenges that must be addressed to optimize the adoption of biocontrol agents in ABC programs for maximum benefit.