Soy Protein Research Articles

Soy Protein and Safflower-Seed Oil Attenuate Inflammation and Immune Dysfunction in Rats with Hyperuricemia

A plant-based diet is considered a promising approach for managing hyperuricemia (HUA). This study examined the effects of soy protein and plant-based oils on HUA-induced inflammation and immune dysfunction. Male Wistar rats, induced with HUA using oxonic acid and uric acid (UA), were fed casein or soy protein with palm or safflower oil (2 × 2 factorial design) for 8 weeks. HUA rats had lower serum albumin and T cell percentages in peripheral blood leukocytes (PBLs) and splenocytes, along with increased leukocyte counts and spleen weights, compared to healthy rats (p < 0.05). Soy protein improved HUA-induced reductions in albumin, while safflower-seed oil ameliorated reductions in albumin, plasma interleukin (IL)-4, and T-suppressor splenocytes, and mitigated elevated serum UA, plasma IL-6, and B leukocytes (two-way ANOVA, p < 0.05). In PBL, soy protein alleviated HUA-induced decreases in TNF-α, casein and palm oil increased IL-6, and casein further reduced IFN-γ production. Under Con A stimulation, casein and safflower-seed oil alleviated decreases in IL-6 and IL-10, respectively, while under LPS stimulation, casein further increased TNF-α production. In splenocytes, soy protein and safflower-seed oil reduced HUA-induced increases in TNF-α and increased IL-10, and safflower-seed oil increased IL-6 production. Under Con A stimulation, soy protein and safflower-seed oil reduced TNF-α and increased IL-10 production in splenocytes. The findings suggest that soy protein and safflower-seed oil may counteract HUA-related inflammation, alleviate monocyte activation, and enhance Th2 immune response in HUA. A plant-based diet rich in soy protein and safflower-seed oil may help manage HUA and associated inflammation and immune dysfunction.

Examining osteoprotective properties of gluten-free bread made with a combination of amaranth and tigernut flours

AbstractGluten-free bread (GFB) consisting of amaranth flour, tigernut (chufa tuber) flour, apple powder, carrot powder, and soy protein isolate can have osteoprotective effects. Glucocorticoid-induced osteoporosis (GIO) was chosen as a model of experimental osteoporosis. Experimental studies were carried out on white male Wistar rats (n = 150): Group 1 – healthy animals receiving standard diet (StD); Group 2 – GIO rats receiving StD; Group 3 – GIO animals receiving zoledronic acid (ZA) and StD; Group 4 – GIO rats receiving ZA and GFB; Group 5 – GIO animals receiving GFB. We evaluated the general condition of animals and carried out morphological and biochemical studies. Destructive changes in the spatial structure of the bone tissue in GIO, observed in Group 2, led to the inability of the bone to withstand the functional load. At the same time, isolated treatment with ZA had virtually no effect on the final morphological picture. Including GFB in the diet of experimental animals both alone and with ZA had a noticeable protective effect on conditions triggering GIO.

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.

Emulsion gels with chia flour enhance quality of plant-based meat analogs by reducing fat and improving texture

Vegetable or coconut oils may negatively impact the texture and lipid profile of plant-based meat analogs. This study aimed to develop emulsion gels (EGs) using olive oil, combined with oat bran, chia flour, and soy protein isolate, to enhance the texture, lipid profile, and overall quality of plant-based patties (PPs). Six EGs were formulated with 40% olive oil and 15 or 20% chia flour, oat bran, or soy protein isolate: chia flour EG (CEG15 and CEG20), oat bran EG (OEG15 and OEG20), and soy protein isolate EG (SEG15 and SEG20). The physicochemical properties of EGs and the physicochemical and sensory properties of the EG-supplemented PPs were examined. The oil-binding capacity was higher in CEG15 and CEG20 followed by SEG15 and SEG20. The overall viscosity was higher in CEG20 and SEG20. All EG-supplemented PP groups showed significantly lower cooking loss, lipid oxidation, and increased water-holding capacity. Particularly, the PP-CEG15 and PP-CEG20 groups exhibited lower exudation rates and higher hardness in the texture analysis than the other groups. Additionally, the PP-CEG groups had desirable sensory scores compared to the other groups. In conclusion, incorporating EGs with different plant-based ingredients, especially chia flour, can enhance the lipid profile and overall quality of PPs.

Deacetylation enhances the structure and gelation properties of konjac glucomannan/soy protein isolate cold-set gels

This study aimed to investigate the effect of the deacetylated konjac glucomannan (DKGM), with varying degree of deacetylation (DD), on the physicochemical and structural properties of transglutaminase-induced soy protein isolate (SPI) cold-set gels. Compared with native konjac glucomannan (KGM), DKGM significantly enhanced the gel strength, water-holding capacity, and thermal stability of the composite gels, with DK3 (DKGM with 65.85 % deacetylation) showing the most significant improvement. The secondary and tertiary structures of SPI in the DK3 group were the most stable. Compared with the KGM group, the DK3 group showed a 58.32 % increase in hydrophobic interaction and a 37.98 % decrease in free sulfhydryl content. The microstructure results demonstrated that DK3 was uniformly dispersed within the SPI network, promoting the formation of a continuous and dense network structure. This was mainly due to DK3 having a moderate particle size and low viscosity. Therefore, DKGM with a moderate DD is conducive to forming a more ordered and dense gel network structure, imparting optimal gel performance to the SPI cold-set gel.

Facile preparation of soybean protein-based oil-resistant paper for food packaging

The use of plastic packaging is harmful to the environment. Due to the advantages of degradability, renewability, and safety of paper packaging materials, replacing plastic with paper has received much attention. However, the poor oil resistance of traditional paper constrains its application. In this research, oil-resistant agent is prepared using soy protein isolate and montmorillonite through physical blending. This oil-resistant agent has advantages of low cost and food safety. Subsequently, food packaging oil-proof paper is obtained by coating the above-mentioned coating on paper. This oil-proof paper has good heat resistance, oil resistance (kit rating is 8/12) and mechanical properties. In addition, it is found that the optimal storage environment for the oil-proof paper. This study provides a feasible method for producing, biodegradable, and eco-friendly food packaging oil-proof paper.

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).

Pickering high internal phase emulsions stabilized by soy protein isolate/κ-carrageenan complex for enhanced stability, bioavailability, and absorption mechanisms of nobiletin

Nobiletin (NOB), a lipid-soluble polymethoxyflavone with potent antioxidant, antimicrobial, and anti-inflammatory properties, suffers from poor stability and pH sensitivity, limiting its bioavailability. In this study, Pickering high internal phase emulsions (HIPEs) stabilized by soy protein isolate (SPI) and κ-carrageenan (KC) were developed to encapsulate and protect NOB. The emulsions, containing a 75 % medium-chain triglyceride (MCT) volume fraction, were optimized by investigating the effects of pH and KC concentration on the key properties such as the creaming index, particle size, zeta potential, microstructure, and rheology. Results showed that under optimal conditions (pH 7 and 1.0 % KC), the SPI/KC HIPEs exhibited improved physicochemical properties. Furthermore, encapsulation of NOB in HIPEs significantly improved its stability against UV exposure, heat, and storage conditions. Additionally, simulated gastrointestinal digestion studies revealed that the SPI/KC HIPEs improved the digestion stability and bioaccessibility of NOB, with controlled release in the intestinal phase. Moreover, the SPI/KC HIPEs facilitated increased cellular uptake and bioavailability of NOB, with clathrin-mediated endocytosis and macropinocytosis as primary absorption pathways. The encapsulated NOB also showed enhanced inhibition of inflammatory markers, including NO, IL-6, and TNF-α. These findings suggested that SPI/KC HIPEs provided a promising delivery system for improving the bioavailability and bioactivity of hydrophobic compounds.

The formation of protein coronas and the interaction of soy protein isolate and whey protein isolate with starch nanoparticles

The influence of food components on the physicochemical properties and biological responses of nanoparticles is pivotal. Since soy protein isolate (SPI) and whey protein isolate (WPI) are commonly used as plant and animal proteins in food, it is imperative to gain comprehensive knowledge of the interaction between SPI/WPI and nanoparticles. Accordingly, we examined the adsorption of SPI and WPI onto starch nanoparticles (SNPs) and their associated interactions. SNP aggregation was observed in the SPI/WPI, and coronas formed around the surfaces of the SNPs. The binding of the protein isolates reduced the zeta potential of the SNPs from −10.34 to −26.5 mV for the SPI and to −21.37 mV for the WPI. However, mixing the SNPs with the protein isolates did not alter the microenvironment of aromatic amino acids and had no substantial impact on the secondary structure of the proteins. Thermogravimetric analysis revealed that the formation of SPI/WPI coronas enhanced the thermal stability of the SNPs. Isothermal titration calorimetry indicated that the adsorption of the SPI and WPI onto the SNPs was driven primarily by weak van der Waals forces and hydrogen bonds. This study facilitates the predicting of organic nanoparticle behaviours in complex food matrix and human gastrointestinal environments.

Silkworm cocoon-like nanocoatings for single-cell encapsulation of probiotics: Construction, mechanism and characterization

Single-cell encapsulation technology is an advanced method to protect probiotics from adverse environmental conditions by forming coating on the surface of individual probiotics. In this study, Lactiplantibacillus plantarum (L. plantarum) was used as model probiotic. Four polysaccharides, namely carboxymethyl chitosan (CMCS), chitooligosaccharide (COS), amylopectin (AP) and pectin (PE), as well as four proteins, namely gelatin (GE), whey protein isolate (WPI), ovalbumin (OVA) and soy protein isolate (SPI), were selected as the initial coating materials. The coated probiotics were prepared by single-cell encapsulation under pH 3.0–6.0 for the first time. The feasibility, mechanism and effect of these coatings were then explored. Results indicated that the positively charged materials were conducive to the formation of coating, and the optimal pH was 4.0. Silkworm cocoon-like coatings with a thickness of 100–150 nm on the surface of L. plantarum were observed. Subsequently, fourier transform infrared spectroscopy (FTIR) analysis showed that electrostatic interaction, hydrogen bonding and hydrophobic interaction were the main driving forces between coatings and L. plantarum. In addition, COS coating fostered the growth and reproduction of L. plantarum, while CMCS and OVA inhibited it. Finally, COS, WPI and GE coatings as barriers all improved the survival rate of L. plantarum under pasteurization, freeze-thaw cycle and storage conditions. Among them, COS as a marine oligosaccharide had the best protective effect on L. plantarum due to its excellent properties and the dense coating it formed. The results may provide more support for further development of nanocoated probiotics.

Structuring chicken breast analogs via high moisture extrusion of dairy-plant proteins blends

Chicken analogs were structured using binary blends of soy protein isolate (SPI) and wheat gluten (WG) or whey protein concentrate (WPC), as well as trinary blends of SPI-WG-WPC via high moisture extrusion. Chicken analogs with anisotropic structures were achieved (anisotropic index >1). Although adding WPC increased hardness, by varying the ratio of SPI to WG in the trinary blends, comparable texture profile properties as cooked chicken breast were achieved. The drivers of the fiber structure formation were non-covalent protein-protein interactions like hydrogen bonds and hydrophobic interactions, and to a lesser extent, inter-protein disulfide bonds formation. β-sheets were the dominant secondary structure, and adding WPC increased the proportion of α-helix while adding WG increased the proportion of β-turns in the meat analog (MA). This study offered strategies on structuring extruded chicken analogs with WPC, a high-quality protein source, and provided insights into mechanisms underlying the formation of fiber structures.

High-intensity ultrasound-assisted alkaline extraction of soy protein: Optimization, modeling, physicochemical and functional properties

This study examined the effect of high-intensity ultrasound-assisted alkaline extraction (HUAE) on the extraction yield and the physicochemical and functional properties of soy protein (SP) using the two-pot multivariate method for the first time. Plackett-Burman Design (PBD) coupled with Response Surface Methodology (RSM) was systematically utilized to select and subsequently optimize the HUAE parameters. Based on PBD results, the significant extraction factors were liquid to solid ratio (LSR), temperature, ultrasonic amplitude, and extraction time. The optimum conditions for the maximal extraction yield and minimal energy consumption were 50:1 mL/g LSR, 50 °C, 48 % ultrasonic amplitude, and 10 min extraction time. At optimum conditions, the extraction yield (35.28 %) was significantly improved compared to traditional extraction (26.39 %). Besides, HUAE resulted in modification of the protein secondary and tertiary structures due to the unfolding of protein molecules and the exposure of hydrophobic groups or regions as shown by FTIR spectroscopy, free sulfhydryl analysis, and scanning electron microscopy. These structural changes led to decreased solubility and emulsifying activity but improved emulsion stabilization and antioxidant properties. With future development, HUAE could potentially produce soy protein for targeted applications, broadening its utilization and meeting the need for more sustainable alternative processing.

Adsorption mechanism of soy protein amyloid fibrils with different morphological structures at the interface of oil-in-water emulsion

Under specific processing conditions, globular food protein can form amyloid fibrils with excellent functional properties in food processing. Amyloid fibrils can be adsorbed on the surface of oil droplets to improve the stability of oil-in-water emulsion. The protein can form monomers oligomers, protofibrils and mature fibrils of which the concentrations increase with the prolonging acidic-heating time. However, the structural advantages of these aggregates when adsorbing at oil-water interface are unclear and the emulsifying ability and adsorption mechanism of food protein amyloid fibrils with different morphology at oil-water interface need to be studied in depth. Herein, four kinds of soy protein amyloid fibrils (SAFs) with distinct morphology were prepared by changing the acidic heating time (3, 6, 12 and 24 h), which were referred as SAFs-3, SAFs-6, SAFs-12 and SAFs-24. Their interfacial adsorption behavior at the oil-water interface were studied systematically by three-phase contact angle, interfacial tension, CLSM, Cryo-SEM and other characterization techniques. The results suggested that the length and flexibility of the fibrils have a great influence on the interface properties, including the rheological properties such as viscosity and modulus. These properties determine the emulsifying capacity of the fibrils. The emulsion stabilized by SAFs-12 was the most resistant to coalescence because SAFs-12 formed a stronger interfacial layer around the oil droplets and a denser viscoelastic network in the continuous phase. In our study, a stabilizing emulsion was prepared using SAFs, which provided potential applications for amyloid fibrils in the food field.

The effects of soy protein and soy isoflavones intake on chronic kidney disease: a systematic review and meta-analysis.

Existing literatures on the potential impact of soy protein consumption on kidney function present conflicting findings. In this study, a meta-analysis has been conducted to assess the impact of soy protein consumption in comparison to animal protein consumption among individuals with chronic kidney disease (CKD). A structured electronic search was conducted on Medline, EMBASE, and Cochrane Library for randomized controlled trials published up to March 2024. The outcome measures were serum creatinine (SCR), triglyceride (TG), total cholesterol (TC), calcium (Ca), C-reactive protein, proteinuria, high-density lipoprotein (HDL), low-density lipoprotein (LDL), uric acid (UA) and phosphorus concentrations. Mean differences were calculated for net changes using random-effects models. Eighteen trials with a total of 522 participants were included in this systematic review. The results showed that consumption of soy protein led to a significant decrease in total cholesterol, LDL, and proteinuria levels. The average reduction was - 20.55mg/dL (95% CI - 38.25, - 2.85mg/dL) for total cholesterol (P = 0.02), - 8.26mg/dL (95% CI - 13.35, - 3.17mg/dL; P = 0.001) for LDL and - 140.53 (95% CI - 205.83, - 75.23mg/day) for proteinuria. No statistically significant impact was observed on serum creatinine, triglycerides, calcium, C-reactive protein, HDL, uric acid, or phosphorus levels. The findings of the meta-analysis showed a potential protective impact of soy protein intake on hyperlipidemia and proteinuria inCKD patients. It is important to note that the evidence presented may be of limited accuracy due to relatively small number of trials and participants.

Gelation melioration of clam Meretrix meretrix surimi based on the interactions with different plant/animal proteins

The effects and mechanisms of four exogenous proteins, soy protein isolate (SPI), pea protein isolate (PPI), egg white protein (EWP), and whey protein isolate (WPI), on the gelation of Meretrix meretrix (MM) surimi were investigated. The exogenous protein addition significantly increased the G* of samples to 1.36–1.60 folds compared to the MM group, and the MM/EWP sample presented a better time-stable structure. Furthermore, the incorporation of SPI and EWP reduced expressible water content by 17.51 % and 21.61 % in MM gel, respectively. Moreover, SPI and PPI interacted with water to act as fillers within the MM matrix, where SPI formed larger self-aggregations than PPI. A double cross-linked network was generated by EWP and MM protein, and WPI increased the interaction with MM protein as a binder. This research could provide a theoretical basis for the processing and utilization of exogenous proteins in MM.

Mechanical properties of chicken feather modified soy protein‐based resins and jute fabric‐reinforced green composites

AbstractAgricultural wastes and byproducts offer a vast avenue for replacing commonplace, but environmentally unfavorable, petroleum‐based plastics. Chicken feather fiber (CFF), soy protein isolate (SPI), and jute fabric (JF) are three agricultural materials that can be utilized for creating ‘green’, that is, from nature, resins and composites. This study details the preparation of CFF‐loaded SPI (CFF/SPI) resins and JF/(CFF/SPI) hybrid green composites, both with and without the frequently used toxic crosslinking agent glutaraldehyde (GA), and their respective mechanical properties. Results showed that as CFF loading increased from 0% to 30%, the tensile fracture stress and strain of CFF/SPI resins decreased from 25.2 to 14.3 MPa and from 4.0 to 1.4% respectively, suggesting that CFF acted mostly as filler. JF/(CFF/SPI) composites had higher tensile properties compared to CFF/SPI resins, with fracture stresses and strains ranging from 26.6 to 22.0 MPa and 4.3% to 5.8%, respectively, as CFF loading increased from 0% to 30%. Apart from increasing the flexural modulus, CFF loading did not significantly affect the flexural properties of JF/(CFF/SPI) composites. With any addition of CFF, CFF/SPI resins and JF/(CFF/SPI) composites showed higher mechanical properties than their GA‐crosslinked counterparts, demonstrating that the toxic crosslinker was unnecessary when using the procedure in this work.Highlights Fully green composites produced with viability for furniture applications. Mechanical performance of GA‐free SPI resin negated need of toxic crosslinker. CFF reduced warpage when incorporated into SPI resin, and JF/SPI composite. JF/(CFF/SPI) composites found to be superior mechanically to all CFF/SPI resins. JF/(CFF/SPI) composite mechanically optimized at 10/90 CFF/SPI resin ratio.

Microalgae-loaded SPI-based monodisperse emulsions prepared by PREMIX membrane emulsification: Effect of pH and HHP on droplet size and droplet size distribution

Emulsions containing Chlorella vulgaris (CV), Arthrospira platensis (AP), Soy Protein Isolate (SPI) powders, or their combination as emulsifiers were prepared at 2 or 3 % protein concentration by intramembrane PREMIX membrane emulsification. Then, the effect of pH (3.5, no-change, 10) and HHP (0.1 and 200 MPa) on mean droplet size (MDS) and size distribution (SPAN) of canola oil in water emulsions was assessed. Emulsions with individual emulsifiers showed undesired MDS and SPAN at pH 3.5, while plant-microalgae emulsions presented better MDS and SPAN values at all pHs. Emulsions at pH 10 had better MDS and SPAN values. AP emulsion prepared at 3 % concentrations showed the highest improvement in MDS and SPAN when 200 MPa were applied. HHP had a positive effect when applied to CV-SPI and AP-SPI at 2 % protein concentration. However, an adverse effect was observed at 3 % protein concentration. Microalgae and plant emulsions with interesting properties can be obtained by pH and HHP treatment.

Bio-Valorization of Spent Coffee Grounds and Potato Peel as Substrates for Pleurotus ostreatus Growth

Pleurotus ostreatus, due to its saprophytic nature, can extract nutrients and bioactive compounds from the substrate on which it is grown. This study aimed to assess the effect of adding spent coffee grounds (SCG) and potato peel (PPW) in the wheat straw substrate formulation to grow over the production indicators, physicochemical, techno-functional, total chemical compounds, and antioxidant properties. Treatments were described as follows: T1, wheat straw at 100%; T2, wheat straw at 80% + 10% of SCG + 10% of PPW; T3, wheat straw at 70% + 15% of SCG + 15% of PPW; T4, wheat straw at 60% + 20% of SCG + 20% of PPW. After P. ostreatus growth, non-differences were found in production indicators for T1–T4, including biological efficiency, production rate, and yield. With respect to P. ostreatus dried powders, T1–T4 showed pH values near neutrality concerning soy protein (SP), and the color samples were beige. Also, T2 and T3 exert higher water-holding (WHC) values, while T1–T4 exert higher oil-holding (OHC) and emulsifying capacity (EC) values concerning SP, in dependence on the growth substrate. T1–T4 showed lower swelling (SC) and T1–T3 lower gelling capacity (GC) values. Regarding total chemical compounds and antioxidant properties of P. ostreatus extracts, growth substrate and solvent extraction have an effect on metabolite content and antiradical and reducing power properties. The multivariate analysis revealed that T2 water extracts exert the highest total tannin (TTC) and protocatechuic acid contents (PAC), as well as the highest antiradical (RCSA) and reducing power (RPA) values. In conclusion, this study demonstrated that using SCG and PPW as a partial substitute for substrate (what straw) enhances the physicochemical, techno-functional, and antioxidant activity of P. ostreatus.

Enhancing emulsifying properties of soy protein isolate-wheat starch conjugates: exploring the influence of starch ratio and hydrolysis time

Enhancing emulsifying properties of soy protein isolate-wheat starch conjugates: exploring the influence of starch ratio and hydrolysis time

Pea and soy fortified with leucine stimulates muscle protein synthesis comparable to whey in a murine ageing model

PurposeTo meet the global dietary protein demands, a trend towards plant-based protein (PBP) sources to replace animal-derived protein is currently ongoing. However, PBPs may not have the same anabolic capacity to stimulate muscle protein synthesis (MPS) as dairy proteins. For vulnerable populations with specific medical needs, it is especially important to validate the anabolic properties of PBPs. In this study, a blend of pea and soy protein isolate, with or without additional leucine, was compared to whey protein isolate on MPS in aged mice.Methods25-Months aged C57BL/6J-mice received an oral gavage with 70 mg of whey protein isolate (W), PS protein isolate (PS; ratio 51:49), PS fortified with 19% leucine (PS + L), or 0.5mL water (F). Mice were subcutaneously injected with puromycin (0.04 µmol/g body weight, t = 30 min) and sacrificed 60 min thereafter. Left m. tibialis anterior (TA) was used to analyse MPS by the SUnSET method and mTOR signal transduction proteins. Amino acid concentrations were determined in plasma and right TA. Dried blood spots (DBS) were analysed for postprandial dynamics of amino acids at 10-20-45-60-min.ResultsMPS was significantly increased by W and PS + L (p < 0.003), however not by PS. Pathway protein 4EBP1 showed significant increases with W, PS and PS + L to F (p < 0.0002). W and PS + L increased plasma and muscle free leucine equally, which was confirmed by DBS.ConclusionA PS blend fortified with leucine stimulates MPS comparable to whey protein in this acute murine ageing model. Leucine appears to be the main driver for the anabolic responses observed.