Soybean Protein Research Articles

Microencapsulation of ginger oleoresin through the complex coacervates of gum Arabic and soy protein isolate as the wall materials

In this investigation, the extracted active ingredients of the ginger plant so-called oleoresin have been encapsulated using the complex coacervation method to preserve them from the oxidation reaction during storage at 25 ᵒC for 100 days. The coacervation was carried out by soybean protein isolate and gum Arabic, and the system was compared to the inclusion of β-cyclodextrin (β-CD) and a non-encapsulated oleoresin in terms of the protection from the total phenolic content (TPC) and antioxidant properties against oxidants such as DPPH and H2O2. The soybean protein isolate as a plant derivative is cheaper than the animal proteins such as whey protein and gelatin which were extensively used in the encapsulation of ginger oleoresin and does not create sensitivity in human guts. The encapsulation by the complex coacervation showed advantages in higher oleoresin loading efficiency and encapsulation yield during the preparation and also gained higher protection efficiencies in preserving TPC and antioxidant activities of oleoresin against oxidation during the storage in comparison with the β-CD inclusion. The complex coacervates can preserve up to 95.4% of TPC, and about 97.7% and 98.9% of the original antioxidant activity against DPPH and H2O2 after this period, respectively. At the same storage conditions, the preservation efficiency for TPC and antioxidant activities against DPPH and H2O2 were respectively 88.5, 82.8, and 85.9% for the β-CD inclusion.

Curcumin-loaded soybean-dextran conjugate nanogels: Construction, characterization, and incorporation into orange juice beverage

Although the health benefits of lipophilic bioactive compounds have received tremendous attention from both researchers and manufacturers, the practical application of these micronutrients in aqueous foods is still challenging due to their water insolubility and environmental instability. Therefore, curcumin (Cur) was selected to be encapsulated in soybean protein isolate-dextran conjugate-based nanogels (SDCNG) via the Maillard reaction combined with protein self-assembly to be incorporated into orange juice beverage (OJB) in this study. Cur-loaded SDCNG (Cur-SDCNG) prepared by adding Cur into the SDCNG solution exhibited an encapsulation efficiency of 89.10% ± 1.40% and a loading capacity of 17.11% ± 0.27%, enhanced 1,1-Diphenyl-2-picrylhydrazyl (DPPH) radical and hydroxyl radical (•OH)-scavenging activities and ferrous reducing power, increased retention rate at both natural light and dark environment, and strengthened storage stability. Moreover, the loaded Cur showed a greater bioaccessibility (55.41% ± 0.71%) than free Cur (17.41% ± 1.04%). The OJB fortified with Cur by adding Cur-SDCNG exhibited an increasing color difference, particle size, polydispersity index (PDI), protein content, total soluble solid (TSS), and sensory score with the increasing Cur concentration. DPPH radical and •OH-scavenging activities and ferrous reducing power also further enhanced. The Cur-fortified OJB with an orange juice concentration of 30% exhibited improved quality attributes and satisfactory stability reflected by the increased TSS and sensory score, acceptable particle size, PDI, centrifugal sedimentation rate, and Cur retention rate under cold conditions. In conclusion, the findings confirmed the effectiveness of Cur encapsulation in SDCNG and the application feasibility of Cur-SDCNG in acidic beverages simultaneously fortified with lipophilic bioactive compounds and vegetable proteins.

Ultrasonic-microwave technique promotes the physicochemical structure of hydrogel and its release characterization of curcumin in vitro

In this study, soybean protein isolate and hawthorn pectin were mixed to prepare binary hydrogels using ultrasound and microwave techniques. Moderate treatment can not only significantly improve the mechanical strength of the hydrogel, but also increase the tightness of the internal cross-linking. The strengthening of interactions (hydrogen bonds, hydrophobic interactions, and disulfide bonds) was the main reason for this trend. Especially, the ultrasonic-microwave (80 s) treatment hydrogel possessed excellent hardness (33.426 N), water-holding capacity (98.26%), elasticity (G′ = 1205 Pa), and a more homogeneous and denser microstructure. In addition, the hydrogel minimized the extent of curcumin loss (21.23%) after 5 weeks of storage. In general, the ultrasonic-microwave technique could significantly promote the physicochemical structure and curcumin bioaccessibility of hydrogels, which showed excellent market prospects in the food industry.

Purification, characterisation and visualisation of soybean protein hydrolysis by aspergillopepsin I from mangrove Aspergillus tubingensis

In order to obtain marine-derived enzymes suitable for protein hydrolysis in acid brewing system, seven species of fungi were obtained from mangrove soil. One of the strains, Aspergillus tubingensis, was determined to have a high acid protease production capacity. Its fermentation broth was purified and the obtained protease was identified as aspergillopepsin I (ATAP) with a molecular weight of 41205 Da. Homology modelling shows that ATAP contains three active sites, each containing to a Zn atom and amino acid residues. The enzyme had the highest relative activity at pH 3.5 and 35–40 °C, and exhibited pH and thermal stability at pH 3.0–3.5 and 20–50 °C. ATAP showed certain salt tolerance. K+ and Zn2+ promoted the enzyme activity, while Mg2+, Cu2+, Co2+, and Fe2+ slightly inhibited the enzyme activity. The results of inhibitors suggest that ATAP belongs to the class of aspartic proteases containing metal atoms. Furthermore, the results of enzymatic hydrolysis of defatted soybean powder showed that the contents of soluble protein, amino nitrogen, free amino acids and the proportion of small molecular peptides (<3 kDa) in the hydrolysate increased significantly. In addition, molecular docking of ATAP and aspergillopepsin I from Aspergillus oryzae 3.042 with soybean globulins (7S and 11S), respectively, showed better hydrolysis of soybean globulins by the former, especially for 7S globulin. Visual analysis indicated the interaction forces between enzymes and soybean globulins were dominated by hydrogen bond and hydrophobic interaction. In conclusion, ATAP may be a candidate as an enzyme preparation for the hydrolysis of soybean proteins.

Handling-friendly, waterproof, and mildew-resistant all-bio-based soybean protein adhesives with high-bonding performance via bio-inspired hydrophobic-enhanced crosslinking network

Eco-friendly and formaldehyde-free soybean protein adhesives are highly attractive to the wood-based panel industry but typically suffer from low water-resistant bonding strength, high viscosity, and susceptibility to mildew. Inspired by adaptive hydrophobic and hydrophilic interactions of mussel foot proteins, herein, a high-performance and versatile all-bio-based adhesive (STF) was synthesized through employing bio-derived furfural and natural tannic acid to assist soybean protein in developing a biomimetic physical/chemical cross-linking network. The collaboration of the hydrophobic furan ring and the hydrophilic catecholic moiety endowed the as-prepared STF adhesives with exceptional water-resistant bonding strength, easy-coating performance, and mildew resistance. Compared to the original soybean protein, the optimal STF demonstrated dry and wet shear strengths of up to 2.52 MPa and 1.71 MPa, respectively, representing an increase of 65.8 % and 263.8 %. Notably, the aged bonding strength of STF surpassed that of previously reported soybean protein-based adhesives with a value as high as 1.19 MPa. The viscosity of the STF decreased by ≈ 98.1 % compared to the unmodified adhesive. Additionally, the STF exhibited excellent mildew resistance (no mildew for 7 days) and storage stability (> 72 h). Combined with life cycle assessment, the biomimetic STF adhesive holds great potential for large-scale production of environment-friendly wood panels.

Stability Evaluation for Main Quality Traits of Soybean in the Northeast and Huang-Huai-Hai Regions

The content of protein and oil in soybeans is an important trait for evaluating quality and is regulated by genetic and environmental factors, lacking comprehensive identification under a variety of ecological conditions. Therefore, evaluating the stability of soybean quality traits under different environmental conditions has great significance for various applications. In this study, we compare 150 soybean varieties from Northeast China (Group A and Group B) and the Huang-Huai-Hai region (Group C). As the release time progressed, the oil content in the soybean varieties showed an upward trend in both Northeast China and the Huang-Huai-Hai region, while the protein content showed a downward trend. Additionally, the oil contents were negatively correlated with the protein contents and the sum of protein and oil contents, while the protein contents were positively correlated with the sum of protein and oil contents, with the correlation becoming stronger as the latitude decreased. Moreover, there were obvious variations in quality stability among different varieties. Hefeng 45, Jilinxiaolidou 4, and Zhonghuang 19 had relatively high protein contents and exhibited good stability across different environments, while Kenjiandou 25, Changnong 17, Dongnong 46, Kennong 17, Liaodou 14, and GR8836 had relatively high oil contents with good stability performance in varying environments.

Spectroscopy combined with spatiotemporal multiscale strategy to study the adsorption mechanism of soybean protein isolate with meat flavor compounds (furan): Differences in position and quantity of the methyl

The interaction mechanism between soybean protein isolate (SPI) and furan flavor compounds with different structures is studied using spectroscopy, molecular docking, and MD simulation methods. The order of binding ability between SPI and furan flavor compounds is 2-acetylfuran>furfural>5-methylfurfural. The structural differences (position and quantity of methyl groups) of three furan flavor compounds are key factors leading to the different adsorption abilities of SPI for furan flavor compounds. The findings from spectroscopy analyses suggest that the interaction between SPI and furan flavor compounds involves both static and dynamic quenching mechanisms, with static quenching being the main factor. Molecular docking and MD simulations reveal the atomic-level mechanisms underlying the stable binding for SPI and furan flavor compounds at spatiotemporal multiscale. This study provides a theoretical framework for the production and adjustment of meat essence formula in the production of soybean protein-based meat products.

Effects of dietary fibres, polyphenols and proteins on the estimated glycaemic index, physicochemical, textural and microstructural properties of steamed bread

SummaryThe effects of dietary fibres, polyphenols, proteins and their combination on the estimated glycaemic index (eGI) of steamed bread, as well as the specific volume, height‐to‐diameter ratio, textural and microstructural properties thereof were studied. The results showed that supplementation of 7% soybean dietary fibre, 10% gallic acid combined with 25% soybean protein isolate significantly reduced the starch digestibility of wheat steamed bread, as evidenced by the significant decrease of eGI value from 88.16 to 49.16, which was classified as low GI steamed bread. While, the addition of soybean dietary fibre, gallic acid and soybean protein isolate together negatively affected the fermentation properties of dough, resulting in lower specific volume, chewiness, springiness and higher hardness of steamed bread compared to wheat bread without any addition. The above results in this study might provide theoretical guidance for the development of healthier and blood glucose‐friendly steamed bread in the staple food industry.

"Microflower-Templated" Janus Sheets: Synthesis and Application in Stabilizing Foams.

In this study, we proposed a method for fabricating Janus sheets using biological "microflowers" as a sacrificial template. The microflower-templated Janus sheets (MF-JNSs) were employed as a foam stabilizer in foam separation of the whey soybean protein (WSP). The MF-JNSs took inorganic hybrid microflowers (BSA@Cu3 (PO4)2-MF) as template, followed by the sequential attachment of protamine and silica to the surface of the BSA@Cu3(PO4)2-MF. Subsequently, the template was removed using ethylenediaminetetraacetic acid after the silicon dioxide was modified by 3-(methacryloyloxy) propyl trimethoxysilane. Upon template dissolution, the modified silica layer, lacking support from the core, fractured to form the MF-JNSs. This method omitted the step of treating the hollow ball by external force and obtained Janus sheets in one step, indicating that it was simple and feasible. The morphology, structure, and composition of the MF-JNSs were analyzed by SEM, TEM, AFM, XRD, and FT-IR. The MF-JNSs were found to delay the breakage time of the Pickering emulsion, demonstrating their emulsion stabilizing capability. Importantly, they significantly enhanced the foam half-life and foam height of soybean whey wastewater (SWW). Moreover, the recovery percentage and enrichment ratio of WSP, separated from SWW by foam separation, were improved to 81 ± 0.28 and 1.20 ± 0.05%, respectively.

Encapsulation of probiotics (Lactobacillus plantarum) in soyasaponin–soybean protein isolate water-in-oil-in-water (W/O/W) emulsion for improved probiotic survival in the gastrointestinal tract

In this study, soyasaponin (Ssa), corn oil, and soybean protein isolate (SPI) were used to prepare a water-in-oil-in-water (W/O/W) double emulsion system that can protect Lactobacillus plantarum (L.P) in the upper gastrointestinal tract for delivery to the small intestine and colon. Incorporating different amounts of L.P (0.1–0.6% (w/v)) in the W/O/W double emulsion caused the viscoelastic modulus and droplet size of the L.P-embedded emulsion system to change, and the emulsion system transformed from a non-Newtonian fluid to a “solid-like” gel. These results revealed that L.P encapsulation led to significantly improved stability of the W/O/W emulsion. In addition, different concentrations of L.P had different effects on the survival rate of L.P in simulated digestive fluids, and after in vitro digestion, L.P was naturally delivered from the stomach into the intestines. The optimal concentration of L.P for obtaining a stable emulsion was found to be 0.3%, and the survival rate of the encapsulated L.P in the small intestine was as high as 78.96% after 1 h. Thus, choosing an appropriate amount of L.P was crucial. The W/O/W emulsion system effectively maintained the viability of L.P and successfully delivered it to the small intestine and colon.

Fermentation with edible mushroom mycelia improves flavor characteristics and techno-functionalities of soybean protein

Fermentation has been considered as an effective strategy for improving the flavor characteristics and techno-functionalities of plant proteins. However, fermentation of soybean protein with mycelia of edible mushrooms has not been reported yet. In this study, edible mushrooms of Morchella Crassipes, Hedgehog Fungus, and Shiitake mushroom were selected for mycelium fermentation of soybean protein isolate (SPI). Mycelium fermentation modified the flavor profile of SPI in strain-dependent manner as indicated by electronic nose analysis. Sourness, bitterness, and astringency of SPI were altered after fermentation with increased proportion of sweet and tasteless amino acids. While, the proportion of bitter amino acids in SPI after 6 days fermentation with Morchella Crassipes (9.88%) was significant decreased as compared with that of untreated SPI (47.95%). Besides, off flavor of SPI was improved by fermentation as indicated by HS-SPME-GC-MS analysis with the relative content of hexanal be reduced from 22.40% to 6.93% after 6 days fermentation with Morchella Crassipes. Moreover, newly formed flavor compounds of benzaldehyde and 5-hydroxymethylfurfural have been identified after fermentation of SPI with mycelia of the selected edible mushroom. Fermentation with mycelium of Morchella Crassipes for six days significantly decreased surface hydrophobicity but increased sulfhydryl content in SPI with changed structural features. Those might contribute to the increased protein solubility (81.16 ± 2.77%) and foaming capacity (221.66 ± 2.35%), while the emulsifying capacity of SPI was significantly decreased. Findings gained in this study would benefit the production of soybean protein with superior flavor and techno-functionalities for potential food applications.

Mechanism of l-cysteine-induced fibrous structural changes of soybean protein at different high-moisture extrusion zones

In this study, the fibrous structure formation mechanism of soybean protein during high moisture extrusion processing was investigated using a dead-stop operation, and based on the interaction between soybean protein concentrate (SPC) and L-cysteine (CYS). The thermal properties, SDS-PAGE and particle size distribution of the samples from different extrusion zones were investigated. It was revealed that the addition of a moderate amount of CYS (0.1 %) promoted the fibrous structure formation in the SPC extrudates and optimised the textural properties of the SPC extrudates. In the extruder barrel, addition of CYS (0.1 %) promoted protein depolymerisation and unfolding in the mixing and cooking zones, and facilitated protein aggregation in the die and cooling zones. Protein solubility and raman spectroscopy revealed that disulfide bonds were principally responsible for fibrous structure formation; favoured when the intermolecular disulfide bonds (t-g-t mode) was increased. Finally, the transformation of protein conformation was revealed by secondary structure and surface hydrophobicity, which confirmed that the effect of CYS on protein conformation mainly occurred in the cooling zone. This study provides a theoretical basis for the application of CYS to regulate the fibrous structure of meat analogues.

Phosphorus fertilisation differentially affects morpho-physiological traits and yield in soybean exposed to water stress

Abstract Background and aims Soybean plants frequently encounter challenges such as phosphorus (P) deficiency and water stress in many regions. However, the mechanisms governing low P and water stress tolerance in soybeans at different growth stages remain unclear. This study investigates the effect of P availability and water stress on soybean growth, morpho-physiological traits, and seed yield. Methods We conducted experiments using the soybean genotype (PI 561271) grown under two P levels (10 or 60 mg P kg−1 dry soil) with three watering conditions: well-watered (WW), early water stress (EWS) and terminal water stress (TWS). Plant assessments occurred at the vegetative, flowering, seed formation, and maturity stages. Results Water stress decreased leaf area, shoot and root dry weights, root length, photosynthetic rate, stomatal conductance, total carboxylates, water use, water use efficiency, shoot, root and seed P contents, seed nitrogen contents, and seed yield compared to WW at the corresponding P level and growth stage. P60 significantly increased all parameters except P use efficiency (PUE) under all water treatments. EWS plants supplemented with P60 exhibited the highest root dry weight, root length and total carboxylates. Notably, flowering and seed formation stages had the highest carboxylate proportions (oxalic, malic, malonic and citric acids) under WW and EWS at P60. P10 had significantly higher PUE than P60, irrespective of water treatments during flowering and seed formation, while the opposite trend occurred at the maturity stage. Seed protein content significantly varied between P treatments regardless of the water stress. Conclusions Our findings underscore the adverse impacts of combined low P and water stress on soybean growth, morpho-physiological traits, seed yield and protein content. Moreover, increased P availability alleviated the adverse effects of water stress, highlighting the importance of adequate P fertilisation for soybean resilience to water stress.

Comparison of the quality of soybean meal and oil by soybean production origin

AbstractPrevious reports indicate variable soybean quality parameters exported from different geographic regions. This review compares soybean and soybean co‐products grown under diverse environmental conditions. While numerous studies have been conducted on whole soybean and soybean meal (SBM) composition by origin, similar analysis of soybean oil is lacking. This review has two objectives: 1) summarize soybean and SBM quality by origin using a meta‐analysis approach, and 2) analyze collected crude degummed soybean oil samples that originate from the US, Brazil and Argentina for key quality attributes. Soybeans from Brazil have higher levels of protein (P &lt; 0.05) than US soybeans, but US soybeans have lower heat damage (P &lt; 0.05) and total damage (P &lt; 0.05) than soybeans from Brazil. US and Brazil SBM have higher crude protein (CP) (P &lt; 0.05) than SBM from Argentina. At equal CP content, US SBM had less fiber (P &lt; 0.0001), more sucrose (P &lt; 0.0001) and lysine (P &lt; 0.0001) and better protein quality than South American SBMs. Methionine, threonine, and cysteine levels were similar in soybean protein from US and Argentina and higher than that in soybean protein from Brazil. Crude degummed soybean oil from Brazil had more (P &lt; 0.05) free fatty acids, neutral oil loss, phosphorus, calcium and magnesium than crude degummed soybean oil from the US or Argentina. Our analysis suggests that environmental conditions under which soybeans are grown, stored, and handled can have a large impact on chemical composition and nutrient quality of soybean meal and soybean oil.

Construction and Properties of Oil-Loaded Soybean Protein Isolate/Polysaccharide-Based Meat Analog Fibers.

Rationally designing the fibrous structure of artificial meat is a challenge in enriching the organoleptic quality of meat analogs. High-quality meat analog fibers have been obtained by wet-spinning technique in our previous study, whereas introducing oil droplets will further achieve their fine design from the insight of microstructure. Herein, in this current work, oil was introduced to the soybean protein isolate/polysaccharide-based meat analog fibers by regulating the oil droplets' size and content, which, importantly, controlled the spinning solution characterization as well as structure-related properties of the meat analog fiber. Results showed that the oil dispersed in the matrix as small droplets with regular shapes, which grew in size as the oil content increased. Considering the effect of oil droplets' size and content on the spinnability of the spinning solution, the mechanical stirring treatment was chosen as the suitable treatment method. Importantly, increasing the oil content has the potential to enhance the juiciness of meat analog fibers through improvements in water-holding capacity and alterations in water mobility. Overall, the successful preparation of oil-loaded plant-based fiber not only mimicked animal muscle fiber more realistically but also provided a general platform for adding fat-soluble nutrients and flavor substances.

Construction of emulsion gel based on the interaction of anionic polysaccharide and soy protein isolate: Focusing on structural, emulsification and functional properties

In this study, the effects on the structures and emulsion gels of carrageenan (CA) and gum arabic (GA) with soybean protein isolate (SPI) were investigated. The results showed that CA and GA exposed hydrophobic groups to SPI, and formed complexes through non-covalent interactions to improve the stability of the complexes. Furthermore, the emulsion gels based on the emulsions exhibited that CA formed emulsion-filled gels with higher elasticity, stronger gel strength, and thermal reversibility, whereas GA formed emulsion-aggregated gels with higher viscosity, and a weak-gel network. The results of digestion showed that, CA was more helpful to slow down the release of free fatty acids and protect vitamin E during digestion. Compared with SPI-GA emulsion gel, SPI-CA emulsion gel had better physicochemical properties and stronger network structure. The results of this study may be useful in the development of anionic polysaccharides that interact with SPI, and they may provide new insights on the preparation of emulsion gels that slowly release fat-soluble nutrients.

Adsorption behavior of soybean protein isolate-soyasaponins mixed system at saliva interface and influence mechanism of saponin bitterness presentation

The bitterness of soyasaponins (Ssa) is one of the main causes of undesirable flavors in soy products. In this study, a Ssa-soybean protein isolate (SPI) binary system was constructed to simulate the adsorption behavior of soybean products at the oral-salivary interface and the mechanism of bitter taste development was investigated. The concentration of Ssa with was determined to be the minimum bitterness value approximately 0.5 mg/mL by sensory evaluation and electronic tongue determination. The nonspecific interactions were confirmed by isothermal titration calorimetry (ITC) and endogenous fluorescence measurements. Ssa formed aggregates with SPI that desorbed from the interface into the bulk phase, resulting in a subsequent increase in particle size and turbidity. This study demonstrated the ability of SPI with Ssa at specific concentrations to attenuate the bitter flavor of Ssa, thus providing important implications for increasing the acceptability of soy products.

Characterization and antibacterial of soybean protein isolate composite film with carvacrol and walnut peel extract

In order to alleviate plastic pollution and to substitute specific conventional polymer packaging, this research deployed biodegradable soy protein isolate (SPI) as a basis to create natural polymer composite films, integrating walnut peel extract (WPE) and carvacrol (CV) for their inherent antibacterial properties. The inhibition rates of the SPI/WPE5%/CV5% composite film on E.coli and S.aureus were 99.66% and 99.52%, the DPPH radical was 73.3% and ABTS radical was 95.5%. The SPI/WPE5%/CV5% composite film also exhibited excellent UV-visible barrier properties. Compared with the pure SPI film, the tensile strength of the SPI/WPE5%/CV5% composite film increased by 89.00%, the water solubility increased by 2.67%, and the water vapor permeability was reduced by 7.69%, While the water contact angle increased by 155.93%. Fourier Transform Infrared Spectroscopy studies possibly indicate that the polyphenol-proteins in the SPI/WPE/CV composite film are bound together by hydrogen bonding. X-ray Diffraction study demonstrated that the crystallinity of the SWC films increased. Scanning Electron Microscope results revealed the surface level and internal molecular structure of the SWC films. Thermal weight analysis showed that after adding WPE and CV, the thermal properties of the SWC films improved. This study explored release of the film and found that the composite film can continuously release polyphenols, which play an antibacterial and antioxidant role.

Heat/non-heat treatment alleviates β-conglycinin-triggered food allergy reactions by modulating the Th1/Th2 immune balance in a BALB/c mouse model.

With the increasing popularity of plant protein-based diets, soy proteins are favored as the most important source of plant protein worldwide. However, potential food allergy risks limit their use in the food industry. This work aims to reveal the mechanism of β-conglycinin-induced food allergy, and to explore the regulatory mechanism of heat treatment and high hydrostatic pressure (HHP) treatment in a BALB/c mouse model. Our results showed that oral administration of β-conglycinin induced severe allergic symptoms in BALB/c mice, but these symptoms were effectively alleviated through heat treatment and HHP treatment. Moreover, β-conglycinin stimulated lymphocyte proliferation and differentiation; a large number of cytokines interleukin (IL)-4, IL-5, IL-10, IL-12 and IL-13 were released and interferon γ secretion was inhibited, which disrupted the Th1/Th2 immune balance and promoted the differentiation and proliferation of naive T cells into Th2-type cells. Heat/non-heat treatment altered the conformation of soybean protein, which significantly reduced allergic reactions in mice. This regulatory mechanism may be associated with Th1/Th2 immune balance. Our results provide data support for understanding the changes in allergenicity of soybean protein within the food industry. © 2024 Society of Chemical Industry.

PH-regulated Tannic acid and soybean protein isolate adhesive for enhanced performance in plant-based meat analogues

A food adhesive comprising tannic acid (TA) and soybean protein isolate (SPI) was developed to establish a cohesive bond between soy protein gel and simulated fat. The impact of varying TA concentrations and pH levels on the adhesive’s rheology, thermal stability, chemical structure, and tensile strength were investigated. Rheological results revealed a gradual decrease in adhesive viscosity with increasing TA content. Differential scanning calorimetry (DSC) and thermal gravimetric (TG) results indicated that the stability of the adhesive improved with higher TA concentrations, reaching its peak at 0.50% TA addition. The incorporation of TA resulted in the cross-linking of amino group in unfolded SPI molecules, forming a mesh structure. However, under alkaline conditions (pH 9), adhesive viscosity and stability increased compared to the original pH. This shift was due to the disruption of the SPI colloidal charge structure, an increase in the stretching of functional groups, further unfolding of the structure, and an enhanced binding of SPI to TA. Under the initial pH conditions, SPI reacted with TA's active site to form covalent crosslinked networks and hydrogen bonds. In alkaline condition, beyond hydrogen and ionic bonding, the catechol structure was oxidized, forming an ortho-quinone that crosslinked SPI and created a denser structure. Tensile strength measurements and freeze–thaw experiments revealed that the adhesive exhibited maximum tensile strength and optimal adhesion with 0.75% TA at pH 9, providing the best overall performance. This study provides a new formulation and approach for developing plant-based meat analogues adhesives.