Mixed Gels Research Articles

Proteomic analysis revealing mechanisms of κ-carrageenan modulating the gelling properties of heat-induced microbial transglutaminase cross-linked myofibrillar protein gels

The effects of κ-carrageenan (KC, 0.2 %, w/w) on the gelling properties and microstructures of heat-treated myofibrillar protein (MP) gels mediated by various levels (0, 0.1, 0.3, and 0.5 %, w/w) of microbial transglutaminase (TG) were investigated. The results revealed that regardless of TG level, the existence of KC significantly promoted the forming of disulphide bonds but limited the generation of large-sized protein polymers in MP gel treated with TG alone, as well as subsequently enhanced the water retention ability and gel strength of mixed MP gel, especially in the sample adding 0.3% TG and 0.2% KC, which was clearly verified by the forming of more denser and continuous gel network. Moreover, TG-induced changes in protein structure led to the alteration in the protein profiles of different MP gels, and an obvious down-regulation trend of myosin (Q9TV63, Q9TV62, P79293, and Q9TV61) was identified in the TG-0.3 group. Furthermore, liquid chromatography–tandem mass spectrometry analysis demonstrated that TG mainly induces protein crosslinking in the light meromyosin domain of the myosin rod. Meanwhile, in the presence of KC, the crosslinking-site percentage of the TG-0.3 group decreased from 37.7% to 36.2%, indicating that KC potentially reduces TG-induced crosslinking in MP gels. Thus, our findings illustrate the critical mechanisms underlying the modulation of KC on the gelling properties of TG-mediated MP gels at the molecular level, which providing potential guideline for the combined applications of TG and KC in the meat industry.

Fabrication and characterisation of whey–pea protein‐based emulsion gels induced by transglutaminase cross‐linking

Food industry has partially replaced animal proteins with plant‐derived alternatives, and effects of combining these two types on properties of food systems need to be elucidated. This study fabricated and characterised emulsion gels of mixed whey and pea protein, varying protein mass ratios from 100:0 to 0:100 and oil volumes from 30% to 45%, induced by transglutaminase cross‐linking. An increase in pea protein led to larger particle size and reduced surface charge in the solutions. Emulsion droplet size ranged from 0.60 to 15.17 μm, increasing with higher levels of pea protein and oil. Mixed protein gels exhibited significantly greater hardness compared to gels with individual proteins. Water‐holding capacity of pure whey protein emulsion gels exceeded 90%, while the value remained above 80% when pea protein was less than 50%. Partially replacing whey protein with pea protein may have potential applications in food products such as salad dressings and cheese.

Construction of mixed gels of yolk granules and salted ovalbumin driven by pH: phase behavior and calcium bioaccessibility

Mixed gels of egg yolk granules (EYGs) and salted ovalbumin (SO) with different pH values were constructed to design gels of great quality and nutritional properties. However, the formation and dietary properties of mixed gels may be affected by the phase behavior of the mixed protein solution. In this study, the pH was adjusted from 3.0 to 8.0 to tune phase behavior of mixed protein solution before heating. The results demonstrated the presence of a collapsed gel and a dense phase network at pH 3.0 caused by phase separation. As the pH increased and phase separation disappeared, the EYGs-SO gel network showed a filling network structure and then changed to a loose interpenetrating network gel structure with a decreased fractal dimension (from 2.94% to 2.89%). The interpenetrating network improved gel hardness and water-holding capacity. During gelation, the phase separation reduced the gelation transition temperature. The main forces that support EYGs-SO gel were hydrogen and disulfide bonds. Moreover, EYGs-SO showed greater calcium bioaccessibility (7.85%–8.08%) at pH 3.0, 4.0, and 5.0. In summary, the phase behavior in mixed solution modulates the gelation of mixed gels. The construction of mixed gels also provides ideas and strategies for the value-added utilization of salted egg whites.

Acid gelation of high-concentrated casein micelles and pea proteins mixed systems

The increased demand for plant-based products brings a new challenge to the food industry. Especially, proteins from soy, chickpea, and pea are being highly demanded as food ingredients. However, they still present some drawbacks such as poor techno-functional properties and remarkable beany flavor that hamper their wider application. Contrarily, milk products such as yogurt and cheeses are highly consumed and accepted worldwide. Therefore, the association of plant proteins, such as pea with milk proteins is an interesting strategy to incorporate more plant-based proteins into people’s diet. However, this strategy can largely impact gel formation and final structure. This study aims to develop mixed casein micelles (CMs) and pea proteins gel at high concentrations in four protein ratios, 80:20, 60:40, 40:60, and 20:80 by acidification. The effect of a thermal treatment before gelation was also evaluated. The replacement of CMs for pea proteins disturbed the gel formation at the beginning of acidification, demand more time to increase the G*, being this effect more pronounced as more casein is replaced in the system. Despite of this effect, the final gel elasticity was higher in the presence of pea proteins for the ratios 80:20 and 60:40, probably due to the formation of pea network. It is hypothesized that pea proteins can form a network when surrounded by CMs, however, CMs restrict pea proteins aggregation. This study describes that the final characteristics of mixed gels can be tailored by changing protein ratios and applying thermal treatment before acidification, opening the possibility for the development of innovative food products.

Analysing the self-assembly modes in chiral multi-component gels based on donor and acceptor moieties

ABSTRACT The role of the structural similarity in the individual components on the self-assembly process of multi-component systems was studied by analysing the gelation properties of chiral multi-component gels with structurally similar (enantiomers) and non-similar donor or acceptor moieties. The gelation properties of the individual enantiomers, mixed enantiomers, and mixed chiral donor-acceptor compounds were analysed in various solvents. Analysis of the mechanical strength revealed that the mixed chiral gels were stronger compared to other gels in mesitylene; however, a reverse trend was observed for thermal stability. Scanning electron microscopy (SEM) of the dried gels of the mixed enantiomeric and mixed chiral donor-acceptor gels showed morphological changes indicating different self-assembly modes. Powder X-ray analysis revealed that a co-assembled mode was observed for the mixed gels with structurally similar components. However, a self-sorting nature was observed for the mixed chiral donor-acceptor gel, and the charge transfer interaction between the donor and acceptor played a major role in the self-assembly of these mixed gels. We performed computational studies to predict the electronic distribution in the individual chiral molecules. These results demonstrate that altering the structural features of the individual components is one of the key parameters that control the self-assembly modes of multi-component systems.

Masterly substitution of plant proteins can achieve acceptable sensory and nutritional attributes in meat-reduced surimi gel

Mixing surimi/plant proteins to reduce animal proteins is considered as an effective way to improve the sustainable production of surimi-based products. The effect of partial substitution (10%∼50%, plant proteins/surimi proteins ratio) of surimi proteins by plant proteins (wheat protein, soybean protein, rice protein, and pea protein) on the properties of the composite gels were investigated. The replacement caused the reductions in gel strength and whiteness. There was a slight increase in water holding capacity (WHC) of mixed gels made from soy or pea protein, but decrease in the cereal protein group. E-nose investigations revealed that the reactions to the W5S and W1W sensors caused the scent profiles to shift dramatically as the replacement amount increased. Organoleptic inspection revealed the substitution ratios of wheat protein, soy protein, rice protein, and pea protein to achieve the sensorial rejection were 30%, 40%, 30%, and 40%, respectively. LF-NMR and MRI showed the cereal proteins increased the T22 relaxation time, while the legume proteins caused a reduction. The mixed gels contained all the essential amino acid, and the digestibility in the wheat protein groups was the highest. These results proved an elaborate formulation can achieve balanced sensory and nutritional attributes in surimi gelled foods.

Optimizing gelation properties of mixed meat myofibrillar proteins: investigating the effects of different proportions of beef, pork and chicken on physicochemical, structural and gelation properties.

The gelation properties of myofibrillar protein (MP) directly affect the texture, taste and water-holding capacity (WHC) of meat products. To enhance the gelation properties of single-species meat MP, the present study investigated the influence of different proportions of beef, pork and chicken MP on the physicochemical properties, structure and gelation properties of the MP. The results revealed that, when the proportion reached 5:2:3, the particle size decreases, leading to the maximum decomposition and unfolding of MPs, which exposes a greater number of hydrophobic amino acid residues. These changes promote interactions between protein molecules, especially the unfolding of α-helices and the formation of β-sheets during the heating process, which provides favorable conditions for the formation of protein gels and improves the gel strength and WHC of MP gels. Additionally, scanning electron microscopy revealed that the mixed MP gels are more compact and have more uniform gel networks and pores compared to single-species MP gels. Based on these results, the synergistic effect is induced by the interactions between proteins from different. This research provides a method for the subsequent development of new meat products and improvement of meat product quality, and also lays a theoretical foundation for composite research of proteins from different sources. © 2024 Society of Chemical Industry.

Formulation and Ex Vivo Evaluation of Membrane Permeation Properties of a Mixed Acetaminophen Gel for Rectal Administration

The purpose of this work was to evaluate the permeation of a mixed native starch-based gel of Ipomoea batatas (Convolvulaceae), using acetaminophen as a tracer through a rat rectal membrane (ex vivo method). The formulated gel was composed of a 10 g solution of poloxamer 407 at 20% and 2.5 g of glycerolized potato starch. The gel obtained was a smooth, homogeneous mixed gel with no foam, air bubbles or lumps, there was no characteristic odor, and the gel was whitish in color. This gel was characterized at the physicochemical and rheological level by means of the viscosimeter KINEXUS, pH- meter EUTECH and the study of the permeation was carried out by means of the Ussing chamber of horizontal type (the dual chamber). The formulated mixed gel is thermogelling, rheofluidifying and viscoelastic with a gelling temperature of 23.83; the permeation study gave a relatively low permeation percentage of 0.16% but which can be improved. The different viscoelastic, rheofluidizing and thermogelling characteristics contained in this mixed gel as well as the pH did not influence the permeation of the active ingredient (AP) through the rat rectal mucosa.

Mixed Micellar Gel of Poloxamer Mixture for Improved Solubilization of Poorly Water-Soluble Ibuprofen and Use as Thermosensitive In Situ Gel.

The aqueous solution of binary mixtures of amphiphilic copolymers is a potential platform for fabricating mixed polymeric micelles for pharmaceutical applications, particularly in developing drug delivery depots for a poorly water-soluble compound. This study fabricated and investigated binary mixtures of poloxamer 403 (P403) and poloxamer 407 (P407) at varying P403:P407 molar ratios to develop a vehicle for the poorly water-soluble compound, using ibuprofen as a model drug. The cooperative formation of mixed micelles was obtained, and the solubility of ibuprofen in the binary mixtures was enhanced compared to the solubility in pure water and an aqueous single P407 solution. The binary mixture with the P403:P407 molar ratio of 0.75:0.25 at a total polymer concentration of 19% w/v exhibited the temperature dependence of micellization and sol-to-gel characteristics of the thermosensitive mixed micellar gels. It possessed suitable micellization and gelation characteristics for in situ gelling systems. The release of ibuprofen from the thermosensitive mixed micellar depots was sustained through a diffusion-controlled mechanism. The findings can aid in formulating binary mixtures of P403 and P407 to achieve the desired properties of mixed micelles and micellar gels.

Viscoelastic Reversibility of Carrageenan Hydrogels under Large Amplitude Oscillatory Shear: Hybrid Carrageenans versus Blends.

The viscoelastic response of carrageenan hydrogels to large amplitude oscillatory shear (LAOS) has not received much attention in the literature in spite of its relevance in industrial application. A set of hybrid carrageenans with differing chemical compositions are gelled in the presence of KCl or NaCl, and their nonlinear viscoelastic responses are systematically compared with mixtures of kappa- and iota-carrageenans of equivalent kappa-carrageenan contents. Two categories of LAOS response are identified: strain softening and strain hardening gels. Strain softening gels show LAOS non-reversibility: when entering the nonlinear viscoelastic regime, the shear storage modulus G' decreases with increasing strain, and never recovers its linear value G0 after successive LAOS sweeps. In contrast to this, strain hardening carrageenan gels show a certain amount of LAOS reversibility: when entering the nonlinear regime, G' increases with strain and shows a maximum at strain γH. For strains applied below γH, G0 shows good reversibility and the strain hardening behavior is maintained. For strains larger than γH, G0 decreases significantly indicating an irreversible structural change in the elastic network. Strain hardening and elastic recovery after LAOS prevail for hybrid carrageenan and iota-carrageenan gels, but are only achieved when blends are gelled in NaCl, suggesting a phase separated structure with a certain degree of co-aggregated interface for mixed gels.

Synergistic Effects of Pea Protein on the Viscoelastic Properties of Sodium Alginate Gels: Findings from Fourier Transform Infrared and Large-Amplitude Oscillatory Shear Analysis

The rheological characteristics of pea protein (PP100%) and alginate (AG100%) as pure and mixed gels with different levels of pea protein (AP90:10, AP80:20, and AP70:30) were investigated via large-amplitude oscillatory shear (LAOS) and Fourier transform infrared (FTIR). Small-angle oscillatory shear (SAOS) was carried out for the samples, and a slight frequency dependence of the storage modulus (G′) and the loss modulus (G″) was observed for the pastes and gels, indicating the formation of a weak network, which is crucial for understanding the gel’s mechanical stability under small levels of deformation. Elastic and viscous Lissajous curves from the LAOS measurement at different levels of strain (1 to 1000%) elucidated that the mixed gels formed a strong network, which showed breakdown at high deformation (>100% strain). The synergistic strengthening of the network of the mixture was noticeable in the Fourier transform and Chevyshev harmonic analyses. This analysis indicated that the nonlinearity of e3/e1 and v3/v1 started at higher levels of strain for the mixed gels. The FTIR spectra revealed that there was no strong interconnection by crosslinking between pea protein and sodium alginate, indicating that the synergistic effect mainly came from electrostatic interactions. These findings suggest that combining alginate with pea protein can enhance the mechanical properties of gels, making them suitable for various food applications.

Chitosan-Alginate Gels for Sorption of Hazardous Materials: The Effect of Chemical Composition and Physical State.

Chitosan, alginate, and chitosan-alginate (50:50) mixed hydrogels were prepared by freeze casting, freeze-drying, and subsequent physical cross-linking. Chitosan was cross-linked with citrate and alginate with calcium ions, while the mixed gels were cross-linked with both cross-linking agents. Both cryogels and xerogels were obtained by lyophilization and drying of the hydrogels. We investigated the effect of the chemical composition and the physical state of gels on the gel structure and sorption of model dyes. Alginate and mixed gels cross-linked with Ca2+ ions sorbed 80-95% of cationic dye from the solutions. The chitosan gels are primarily capable of adsorbing anionic dyes, but at near-neutral pH, their capacity is lower than that of alginate gels, showing 50-60% dye sorption. In the case of alginate gels, the dye sorption capacity of xerogels, cryogels, and hydrogels was the same, but for chitosan gels, the hydrogels adsorbed slightly less dye than the dried gels.

Optimization of Vascularized Intestinal Organoid Model.

Vasculature is crucial for maintaining organ homeostasis and metabolism. Although 3D organoids can mimic organ structures and patterns, they still lack vascular systems, limiting the recapitulation ofphysiological complexities. Although vascularization of organoids has been demonstrated by mixing Matrigel in fibrin, how the mixed gel niche affects endothelial cells (ECs) and organoids remains unclear. Existing protocols rely on fibroblasts to promote vascular network formation. This study explores how varying the ratio of Matrigel in fibrin-Matrigel co-gel affects vascular network formation and intestinal organoid growth.A fine-tuned hydrogel is developed by adding aprotinin and 15% Matrigel in fibrin. Medium for co-culturing ECs and organoids is modified with basic fibroblast growth factor (bFGF) and heparin. In combination with fine-tuned hydrogel and modified medium, vascular network formation and organoid vascularization are successfully generated in the absence of fibroblast. Furthermore, structural cues and pore architectures are critical for angiogenesis and vascularization. By incorporating engineered thick collagen fiber bundles into the system, vascular network formation is guided by bundle architectures, enhancing interactions between vascular networks and organoids. The results demonstrate an optimized system that advances tissue and organoid vascularization by combining fiber bundles with fine-tuned hydrogel and modified medium.

Tracking protein aggregation behavior and molecular interactions induced by conformational alterations in the formation of myofibrillar protein-Abelmoschus manihot gum mixed gels during heating process

The present study aimed to systematically investigate the effects of different Abelmoschus manihot gum (AMG) concentrations (0–0.5%, w/w) on the formation of myofibrillar protein (MP) gels during heating process (30–80 °C) based on conformational alterations, protein aggregation behavior and molecular interactions. With the increase of temperature, the fluorescence intensity and α-helix content significantly decreased, revealing conformational transition of MP molecular. Dynamic rheological results indicated that MP had completely denatured and formed temporary gel at 50 °C, and completely formed irreversible cross-linked three-dimensional network structure at 80 °C. Moreover, the addition of AMG decreased the fluorescence intensity, as well as induced the transition of MP from α-helix to β-sheet during the whole heating process. Furthermore, AMG addition significantly decreased the turbidity and improved solubility of MP (P < 0.05), especially for at 0.3% AMG concentration, indicating that AMG accelerated the early unfolding and aggregation of MP during heating process. This was verified by the dynamic rheological results. Additionally, hydrophobic interactions and disulfide bonds were the main molecular forces to induce the formation of MP-AMG mixed gel. Therefore, our present results provided the new insights into the formation of MP-AMG mixed thermal-induced gel, and also contributed to the practical application of AMG in meat processing.

Chemiluminescent Reaction Induced by Mixing of Fluorescent-Dye-Containing Molecular Organogels with Aqueous Oxidant Solutions.

Chemiluminescence in solution-based systems has been extensively studied for the chemical analysis of biomolecules. However, investigations into the control of chemiluminescence reactions in gel-based systems, which offer flexibility in reaction conditions (such as the softness of the reaction environment), have only recently begun in polymer materials, with limited exploration in low-molecular-weight gelator (LMWG) systems. In this study, we investigated the chemiluminescence behaviors in the gel states using LMWG systems and evaluated their applicability to fluorescent-dye-containing molecular organogel systems/oxidant-containing aqueous systems. Using diethyl succinate organogels composed of 12-hydroxystearic acid as a molecular organogelator, we examined the fluorescent properties of various fluorescent dyes mixed with oxidant aqueous solutions. As the reaction medium transitioned from the solution to the gel state, the emission color and chemiluminescence duration changed significantly, and distinct characteristics were observed, for each dye. This result indicates that the chemiluminescence behavior differs significantly between the solution and gel states. Additionally, visual inspection and dynamic viscoelastic measurements of the mixed fluorescent dye-containing molecular gels and oxidant-containing aqueous solutions confirmed that the chemiluminescence induced by the mixing occurred within the gel phase. Furthermore, the transition from the solution to the gel state may allow for the modulation of the mixing degree, thereby enabling control over the progression of the chemiluminescence reaction.

In situ Measurement of Phosphate using Fe3O4/Chelex®100-Agarose-Oxalic Acid Hydrogel in Diffusive Gradient in Thin Films

ABSTRACT. This study would be the first to develop a novel combination of Chelex®100 and Fe3O4 as a mixed binding gel for in situ phosphate measurement employing Diffusive Gradient in Thin Films (DGT). Fe3O4 and Chelex®100 were utilized as binding agents within a single binding layer for phosphate measurements in laboratory and natural water settings. The synthesized Fe3O4 was identified as magnetite and consisted of micro-sized particles. The pore size of the mixed binding gel ranged from 22.39 to 112.5 µm. Incorporating Chelex®100 with Fe3O4 in oxalic acid cross-linked agarose did not diminish phosphate adsorption efficiency. As adsorption time and phosphate concentration in solution increased, the quantity of adsorbed phosphate in the mixed binding gel also increased. Optimal phosphate elution was achieved using a basic solution, with a phosphate elution efficiency of 95.3 ± 0.4% observed with 0.4 M NaOH. The diffusion coefficient measured using the mixed binding gel was 1.08 times greater than that of polyacrylamide cross-linked with an agarose derivative (APA) gel, typically employed in the DGT technique. Phosphate concentration measurement with Fe3O4/Chelex®100-agarose oxalic acid in a DGT passive sampler at pH 4-8 yielded values twice those in bulk solution. Similar results were obtained when measuring phosphate in a 0.01 – 0.1 M NaNO3 solution. A T-test showed that the phosphate concentration obtained from mixed binding layer-DGT as an alternate passive sampler was not significantly different from grab sampling. This study underscores the suitability of Fe3O4-Chelex®100 impregnated in agarose-oxalic acid gel for monitoring phosphate in natural water via DGT. Keywords: Agarose, diffusive gradient in thin films, mixed binding gel Fe3O4, oxalic acid.

Development of novel protein-rich foods: Studies of composite hydrogels formed from potato proteins and gellan gums with different degrees of acylation

The textural attributes of mixed hydrogels formed from potato protein (PP) and gellan gum (GG) were examined for their potential application as novel protein-rich foods (NPFs). Initially, the properties of gels formed by the individual biopolymers were characterized using dynamic shear rheology, compression testing, and confocal fluorescence microscopy. Rheological analysis revealed that PP dispersions formed irreversible heat-set gels, whereas GG formed reversible cold-set gels at lower temperatures. The effects of adding PP to high acyl gellan gum (HA-GG) or low acyl gellan gum (LA-GG) solutions on the microstructure and rheology of the mixed gels formed were then examined. The PP/LA-GG composite gels had a highly heterogeneous microstructure consisting of protein-rich and polysaccharide-rich regions. In contrast, the PP/HA-GG composite gels had a more uniform microstructure. Interestingly, the incorporation of the PP weakened the PP/LA-GG composite gels (antagonism) but strengthened the PP/HA-GG composite gels (synergism), which was mainly attributed to their different impacts on gel microstructure. This study shows that semi-solid plant protein-dietary fiber composites can be formed with a variety of textural attributes by altering the nature and concentration of biopolymers used to formulate them. These mixed gels may be useful for the creation of NPFs. This study also highlights the complexity of the interactions between different food biopolymers and their impacts on food properties, highlighting the need for further research on understanding structure-function relationships in multicomponent biopolymer materials.

Effect of psyllium husk powder on the gelation behavior, microstructure, and intermolecular interactions in myofibrillar protein gels from Andrias davidianus

The interaction between proteins and soluble dietary fibers plays a vital role in the development of animal-derived foods. Herein, the effects of different contents (0–3.0%) of round-bracted psyllium husk powder (PHP) on the gelation behavior, microstructure, and intermolecular interactions of Andrias davidianus myofibrillar protein (MP) were investigated. Rheological and chemical forces suggested that PHP (1.5%–2.0%) enhanced the functional properties of MP at low ionic strength, thereby increasing the viscoelasticity of mixed gels. SDS-PAGE revealed that PHP reinforced the cross-linking and aggregation of protein molecules. Circular dichroism spectroscopy, low-field nuclear magnetic resonance, and scanning electron microscopy demonstrated that PHP induced the transformation of α-helix (decreased by 14.85%) to an ordered β-sheet structure (increased by 81.58%), which was more favorable for the formation of dense network structure and improved (10.53%) the water retention of MP gels. This study provided new insights for PHP to effectively meliorate the heat-induced gelling properties of MP.

Unraveling the mechanisms of pea protein isolate in modulating retrogradation behavior of pea starch

The study investigated the impact of pea protein isolate (PPI) on the short-term and long-term retrogradation behavior of pea starch (PS). Dynamic time scanning and water migration analysis revealed that the presence of PPI enhanced water mobility within the PS gel during short-term storage (4 °C, 8 h) and impeded amylose gelation, effectively suppressing the short-term retrogradation of amylose. Over long-term storage (4 °C, 14 d), PPI reduced the retrogradation enthalpy and the ordered structure of starch molecules. The relative crystallinity and retrogradation degree reduced by 40.6% and 29.9%, respectively, as the PPI content increased from 0 to 12%. Textural profile analysis showed PPI decreased the gel hardness and induced the formation of a weak gel of PS, thereby delaying the long-term retrogradation of amylopectin. Scanning electron microscopy analysis further confirmed that the PS-PPI mixed gel exhibited a more disordered and loose structure compared to the PS gel, which resulted from PPI inhibiting the rearrangement and aggregation of amylose and amylopectin molecules. These findings suggested that PPI exhibited the potential to inhibit the short-term and long-term retrogradation of PS, thus providing valuable theoretical evidence for enhancing the development and research of pea-based products.

Digestion of mixed protein gels using elderly static in vitro digestion model: Impact of microstructure on bioaccessibility of vitamins B12 and D3

The intake of food products that provide adequate amounts of nutrients is a strategy to deal with the changes in physiological functions that occur during aging that can lead to malnutrition. In this work heat-set mixed protein gels (MPG) composed of soy protein isolate (SPI) and whey protein isolate (WPI) are developed, with different SPI:WPI ratios (15 g protein isolate/100 g gel) and enriched with vitamins D3 and B12. Different protein ratios formed gels with different microstructures and rheological properties. The gel containing 70 % of WPI had a more homogeneous microstructure. The influence of the MPG microstructure on the digestion and bioaccessibility of proteins and vitamins using elderly static in vitro digestion was evaluated. An important result is that mixing SPI and WPI increased the proteolysis. Regarding vitamins bioaccessibility, vitamin D3 became more bioaccessible after the intestinal phase, and there was no difference in vitamin B12 concentration in the intestinal and gastric phases. Therefore, mixing SPI and WPI to produce MPG resulted in improved digestion of proteins, as well as higher bioaccessibility of the vitamins. The results indicated the MPG are promising protein matrices to be used in food products for the elderly.