查找使用阿拉丁产品的科研文献

Bonding and fracture properties of SPI-CNTs/epoxy adhesive on SPI-CNTs deposited CFRP composites

Jiayu Li,Junjie Zhao,Lei Hao,Yichao Li

Adhesive bonding is frequently used to connect CFRP structures due to its lightweight, easy implementation and high production efficiency. However, the bonding performance of adhesive is far from satisfactory as dimension and complexity of CFRP structures increase. In this paper, a new bonding strategy for CFRP structures via introducing soy protein isolate modified carbon nanotubes (SPI-CNTs) both in the epoxy resin adhesive and on the bonding parts' surface is proposed. Results showed that SPI can effectively improve CNTs' dispersion on the two areas, notably enhancing the bonding performance of the adhesive. When 0.3 wt% SPI-CNTs was added in the adhesive, its adhesive shear strength increased to 12.76 MPa, which was 72 % higher than the unmodified CNTs/epoxy adhesive. Based on this concentration, the SPI-CNTs was deposited uniformly on the surface of the CFRP adherends via bath sonication and resulted in a maximum shear strength of 15.59 MPa, which was 22.2 % greater than the untreated ones. Based on the above condition, the Mode I fracture toughness G 1c and the Mixed-Mode I/II fracture toughness G c could reach a maximum of 0.31 and 0.44 N/mm respectively, which were 117 % and 97 % higher than the pure epoxy adhesive . The present work shows a new pathway for the effective bonding of CFRP structural components used in the aerospace industry.

Ball-milling changed the physicochemical properties of SPI and its cold-set gels

Bohui Liu,Hui Wang,Tan Hu,Peipei Zhang,Zhuo Zhang,Siyi Pan,Hao Hu

In this study, the effect of ball-milling (BM, Mixer Mill MM 400) treatments on the physicochemical properties of soybean protein isolate (SPI) and its cold-set gels induced by glucono-δ-lactone was studied. BM of SPI increased the gel strength and water holding capacity of cold-set gels significantly after 4 min of BM treatments. BM treatments did not alter the primary structure of SPI, but caused minor changes of the secondary structure. Furthermore, surface hydrophobicity of SPI increased gradually from 2058 to 5051 after 10 min of BM, while free SH groups reduced from 3.92 to 2.65 μmol/g protein. Moreover, near-UV CD spectra indicated that the tertiary conformation stability was increased and the hydrophobic groups might shift to a more hydrophobic microenvironment. In conclusion, appropriate BM treatments could change the physicochemical properties of SPI and increased the gelation properties of SPI cold-set gels.

Effect of simultaneous treatment combining ultrasonication and pH-shifting on SPI in the formation of nanoparticles and encapsulating resveratrol

Zheng Fang,Xixi Cai,Jiulin Wu,Lingtuo Zhang,Yapeng Fang,Shaoyun Wang

Plant protein-based nano-delivery systems have rencently drawn increasing attention, and several physical and chemical methods for improving the functional properties of plant proteins have been reported. In this work, we applied ultrasonication and pH-shifting combined treatment on soy protein isolates (SPI) and investigated the structure changes of SPI and its effects on the formation of SPI- sodium alginate (Alg) electrostatic complex and SPI-resveratrol nanocomplex. It was found that the combined ultrasonication/pH-shifting treatment resulted in a smaller particle size and larger surface hydrophobicity, which were 114.6 ± 1.2 nm and 12741 ± 456, respectively. During the formation of the complex with Alg , compared with pH-shifting or ultrasonication treatment, the combined ultrasonication/pH-shifting treatment expanded stable region, where the particle size was smaller and the binding constant with sodium alginate was higher. Moreover, the encapsulation efficiency of resveratrol in SPI increased to 91.4 ± 4.3% after the combined ultrasonication/pH-shifting treatment. Thus, simultaneous treatment combining ultrasonication and pH-shifting was significantly more effective than ultrasonication alone and was thought as an effective method for protein modification.

Comparative study of Maillard reaction and blending between soybean protein isolate and soluble soybean polysaccharide: Physicochemical, structure and functional properties

Chuxin Ke,Shaoqi Zhang,Xiaoyu Yang,Liang Li

Soybean protein isolate-soluble soybean polysaccharide (SPI-SSPS) complexes and mixtures with varying SPI/SSPS concentration ratios (1: 1, 2:1, 4:1, 8:1) were prepared by Maillard reaction and blending, respectively, and their physicochemical, structure, and functional properties were compared studied. The physical stability of SPI-SSPS complex, which consisted of C N and C S bonds, was better than that of the SPI/SSPS mixture with electrostatic interactions and hydrogen bonds, and both were superior SPI alone. The complex with SPI/SSPS concentration ratio of 8:1 had the highest grafting degree (33.25 %) and a more ordered structure, making its solubility and emulsifying property lower than the SPI/SSPS mixture; however, the physical and thermal stability of the SPI-SSPS complex was higher than that of the SPI and SPI/SSPS mixture. In particular, the SPI-SSPS complex with a high grafting degree showed a higher thermal denaturation temperature (194.06 °C). This study aimed to provide effective modification methods to utilize soybean processing by-products by modifying soybean protein isolate with soluble soybean polysaccharide.

Construction and Properties of SPI/PLA-PCL Composite Coating on Pure Titanium Surface

Chunmei Wang,Congyi Zhu,Qi Zhang,Shuangsheng Zhang,Ling Zhang,Jiang Wu,Guoliang Zhang

Titanium and titanium alloys have been widely used in clinical implants such as dental implants due to their high strength and corrosion resistance. However, their inherent biological inertness and mismatch with the elastic modulus of human bone tissue restrict bone healing and reconstruction. In this study, pure titanium was first modified by micro-arc oxidation (MAO), and then a biodegradable soybean protein isolate (SPI)/polylactic acid (PLA)–polycaprolactone (PCL) composite coating was prepared by using the spin-coating method. The coating was systematically characterized by scanning electron microscopy (SEM), an energy spectrometer (EDS), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), and atomic force microscopy (AFM), confirming that the composite coating was successfully prepared. An evaluation of the physical and chemical properties showed that the introduction of SPI significantly improved the hydrophilicity, surface roughness and adhesion to the substrate of the coating, regulated the degradation rate, and reduced the elastic modulus to the range of 10–30 GPa, which matches human bone tissue. At the same time, it enhanced corrosion resistance. In vitro MC3T3-E1 osteoblast experiments showed that the coating containing 50% SPI showed better cell compatibility, adhesion ability and osteogenic inducibility, and all groups had good blood compatibility. The SPI/PLA–PCL composite coating effectively improves the biological activity of the pure titanium surface and provides a feasible strategy for the surface modification of titanium implants and bone defect repair.

Effects of ultrasound on structural and physical properties of soy protein isolate (SPI) dispersions

Hao Hu,Jiahui Wu,Eunice C.Y. Li-Chan,Le Zhu,Fang Zhang,Xiaoyun Xu,Gang Fan,Lufeng Wang,Xingjian Huang,Siyi Pan

The effects of low-frequency (20 kHz) ultrasonication at varying power (200, 400 or 600 W) and time (15 or 30 min) on functional and structural properties of reconstituted soy protein isolate (SPI) dispersions were examined. Ultrasonic treatments reduced both the storage modulus and loss modulus of SPI dispersions and formed more viscous SPI dispersions (fluid character). Moreover, ultrasound treatment significantly decreased the consistency coefficients and increased the flow behaviour index of SPI dispersions. Scanning electron microscopy of lyophilized ultrasonicated SPI showed different microstructure with larger aggregates compared to non-treated SPI. No significant change was observed in the protein electrophoretic patterns by SDS-PAGE. However, free sulfhydryl content, surface hydrophobicity and protein solubility of SPI dispersions were all increased with ultrasonic treatment. Differences in solubility profiles in the presence versus absence of denaturing (0.5% sodium dodecyl sulphate and 6 M urea) and reducing (mercaptoethanol) agents suggested a decrease in non-covalent interactions of SPI in dispersion after ultrasonic treatment. Secondary structure analysis by circular dichroism indicated lower α-helix and random coil in SPI treated at lower power, in contrast to higher α-helix and lower β-sheet in SPI treated with higher power (600 W). In conclusion, under the conditions investigated in this study, ultrasonic treatment resulted in partial unfolding and reduction of intermolecular interactions as demonstrated by increases in free sulfhydryl groups and surface hydrophobicity, leading to improved solubility and fluid character of SPI dispersions, while larger aggregates of ultrasonic-treated SPI in the dry state were formed after lyophilization.

Alginate-shelled SPI nanoparticle for encapsulation of resveratrol with enhanced colloidal and chemical stability

Lingtuo Zhang,Fang Zhang,Yapeng Fang,Shaoyun Wang

Utilization of protein-based nanoparticles encapsulating resveratrol is hampered by their instability against the environmental stress including pH, ionic strength and UV light. In this study, we fabricated a sodium alginate (Alg)-shelled soy protein isolate (SPI) nanoparticle for the encapsulation of resveratrol, abbreviated as RSAN. The aim of this study was to investigate the existence of Alg shell on both colloidal and chemical stabilities of RSAN. RSAN, fabricated at pH 3.5 and 0.25 mg/mL of Alg, is 204.5 ± 12.1 nm in diameter, −36.4 ± 1.2 mV in ζ-potential and 91.9 ± 3.3% in encapsulation efficiency of resveratrol. RSAN exhibited consistent solubility from pH 2.0 to 8.0 and was resistant to precipitation in ionic strength of 400 mM NaCl at various pHs. The protein in RSAN was prevented from digestion in gastric. Only 15% trans-resveratrol in RSAN was isomerized after 30 min UV light exposure, which is approximate 30% less than the non-shelled nanoparticle (RSN). Moreover, the encapsulation of resveratrol did not reduce its antioxidant activity . The findings suggest that this Alg-shelled nanoparticle has a potential in encapsulating hydrophobic bioactive compounds for utilization in functional foods.

Polyelectrolyte Complex/MMT Hybrid for SPI/WE Adhesives with Balanced Flame Retardancy and Shear Strength

Soybean protein isolate (SPI) adhesives are eco-friendly but suffer from poor water resistance and bonding strength. Waterborne epoxy (WE) can effectively improve these properties; however, WE-modified SPI adhesives can hardly satisfy the growing stringent flame-retardant demands for plywood. Herein, we report a composite adhesive (SPI/20WE/THPS@CS/MMT) that simultaneously exhibits favorable flame retardancy and dry and wet shear strengths. In this system, a phosphorus-, nitrogen-, and sulfur-containing polyelectrolyte complex (THPS@CS) is fabricated by vacuum-drying an ionically crosslinked polyelectrolyte hydrogel derived from bis[tetrakis(hydroxymethyl)phosphonium] sulfate (THPS) and chitosan (CS) and subsequently incorporated into the SPI/WE matrix (SPI/20WE) together with montmorillonite (MMT). The plywood bonded with SPI/20WE/THPS@CS/MMT achieves a limiting oxygen index (LOI) of 28.0% and shows significantly reduced heat release in cone calorimeter tests. Meanwhile, the resultant plywood possesses high dry and wet shear strengths that fulfill the interior-use plywood criteria specified in GB/T 9846–2015. This work offers new insights into the design and fabrication of high-performance eco-friendly plywood adhesives.

Effect of Plasticizer Content on the Structure and Properties of SPI/MA-g-PBAT Blend Films

Gong Ping,Zhao Youxi,Li Ke,Tian Huafeng,Li Chuanming

Soy protein isolate (SPI) has the advantages of low cost, easy processing, stable performance and so on. However, the processing temperature of SPI is high, the processed products are hard and brittle with high water absorption capacity, so it is necessary to modify the soybean protein during processing. Small molecule plasticizer is commonly used globally to plasticize and modify soybean protein. Different plasticizer content has different plasticizing effect on protein, and the properties of materials prepared will also vary greatly. The plasticizer can affect the viscosity of the blends morphology and properties by changing the viscosity of protein phase. In this work, glycerol with the excellent plasticizing effect was selected as plasticizer, and SPI was plasticized with glycerol of different contents, and then the plasticized SPI was blended with poly (butylene adipate-co-terephthalate)(PBAT) to prepare biodegradable blend materials. The influence of plasticizer content on the structure and properties of the blends was explored by observing the microstructure, mechanical and thermal properties of the blends. The results showed that with the increase of glycerol content, the crystallization temperature and melting temperature of the blend system increased, the chain segment was easier to move, and the glass transition temperature(Tg) decreased. At the same time, the viscosity of the blending system decreases, which improves the processing fluidity of the system.

Effects of a Nanoparticle-Loaded PVA/SPI Pad on Microbial Proliferation and Quality Characteristics of Superchilled Pork

Haoyue Wu,Yi Zhou,Huaxing Xu,Zhaoming Wang,Xingguang Chen,Hui Zhou

Fresh pork remains susceptible to psychrotrophic spoilage during superchilled storage. Although oregano essential oil (OEO), nisin, and active absorbent pads have each been studied, their effects on spoilage-community proliferation and concurrent quality loss remain poorly resolved. Here, we coupled longitudinal 16S rRNA gene profiling with conventional microbiological and quality measurements to evaluate a poly(vinyl alcohol)/soy protein isolate pad containing OEO-loaded soluble soybean polysaccharide-nisin nanoparticles (PS-NPs). Pork was stored at −1 °C for 24 days without a pad (CK), with a nanoparticle-free pad (PS), or with PS-NPs. Bacterial communities in CK and PS-NPs were profiled alongside total viable count, TVB-N, TBARS, protein carbonyls, color, water-holding capacity, and sensory quality. Compared with CK, PS-NPs slowed the increase in viable counts and delayed physicochemical and sensory deterioration. On day 24,Pseudomonasrelative abundance was 39.48% with PS-NPs and 51.02% in CK. TBARS and protein carbonyl contents were 36.96% and 19.44% lower than CK, respectively, while cooking loss was 28.49% versus 32.18%. Among the evaluated taxon-quality pairs,Pseudomonas psychrophilashowed the strongest positive association with protein carbonyl content. Unlike earlier performance-focused studies, this work links packaging-associated community shifts with concurrent chemical, physical, and sensory changes under superchilling. The findings support PS-NPs as a preservation strategy.

Freeze–thaw stability of pickering emulsions stabilized by SPI-chitosan and its application in frozen pork patties

Huiyun Zhang,Xinling Li,Weishi Shan,Jingkun Guo,Xuyang Hu,Huaibin Kang

This study investigated the freeze-thaw (F-T) stability of Pickering emulsions (PEs) prepared from soy protein isolate (SPI) and chitosan (CH), and their application in frozen pork patties. SPI-CH stabilized PEs were prepared at CH concentrations of 0, 0.5 %, 1 %, 1.5 %, and 2 %. The F-T stability of PEs was evaluated through measuring the creaming index, particle size distribution, ζ-potential, and observing the microstructure. Results showed that PEs exhibited optimal F-T stability when the CH concentration reached 1.5 %. After three F-T cycles, the creaming index was minimized, decreasing by 54.3 % compared to the control group. The droplet size distribution became single-peaked and minimized, effectively enhancing emulsion stability. Incorporating SPI-CH stabilized PEs into frozen pork patties significantly improved product quality. Patties containing 6 % PEs performed best, showing improved water-holding capacity with the lowest thawing loss (5.8 %). They also maintained better color stability and exhibited a more desirable texture due to restricted water migration. This research provides a strong foundation for developing food-grade Pickering particles and improving the quality of frozen meat products. Future studies should further explore the potential applications of these particles in a wider range of frozen foods.

The influence of protein oxidation on structure, pepsin diffusion, and in vitro gastric digestion of SPI emulsion

Jie Zhao,Shuaiqian Wang,Diandian Jiang,Chong Chen,Jie Tang,Igor Tomasevic,Weizheng Sun

The stability behaviors of oxidized SPI emulsions under in vitro gastric conditions and the effects of pepsin diffusion on the proteolysis of emulsions were investigated using a static gastric model and the fluorescence recovery after photobleaching method. Results showed that protein oxidation increased the particle size of droplets and decreased the viscoelasticity of the interfacial layer. Compared to the control group (82.81 m 2 /s), the pepsin diffusivity decreased to 68.52 m 2 /s (7LA +  LOX group) due to the space hindrance of oil droplets. After gastric digestion, protein hydrolysates were re-absorbed on the oil–water interface and formed a thick layer, thereby decreasing the size of oil droplets and reducing the contents of free amino acids in gastric digesta. The protein oxidation may affect the adsorption of interfacial proteins and alter the distribution of droplets, decreasing pepsin diffusion and ultimately impairing the emulsion gastric digestion. And this should be considered in the design of emulsion as the controllable delivery system.