Engineering Processes for Plant‐Based Meat Analogs: Current Status and Future Outlook

Wet extrusion is a high‐moisture processing method used to transform plant‐based proteins into fibrous structures that closely replicate the texture and anisotropic properties of animal muscle (Dinali et al. 2024). In this process, a heterophase blend of often incompatible water‐plasticized biopolymers (proteins and some starch) is brought to high temperatures and pressures. The process begins with a thermoplastic transition, wherein proteins denature under the influence of heat, mechanical energy, and moisture. In this step, proteins lose their native globular conformation as heat unfolds their polypeptide chains, exposing internally buried hydrophobic and reactive groups that engage in intermolecular interactions (Guyony et al. 2023). Water, at a high concentration of 40%–80%, acts as a plasticizer, softening the protein matrix and increasing its molecular mobility. This plasticized state allows proteins to flow and deform under applied shear forces, forming a molten matrix suitable for restructuring (Chen et al. 2010). As the molten mass advances through the extruder, shear‐induced alignment occurs, a critical stage in forming fibrous textures. Shear forces generated by the rotation of screws and the barrel's constriction align protein molecules in the flow direction. This molecular alignment is pivotal for achieving anisotropic structures that replicate the striated texture of muscle fibers (Cornet et al. 2022). During this phase, reformation of covalent bonds, such as disulfide bridges, and noncovalent interactions, including hydrogen bonds and hydrophobic associations, reinforces the aligned protein network (Nasrollahzadeh 2023). These interactions stabilize the structure, giving it the mechanical properties necessary to mimic meat textures. Additionally, the viscoelastic behavior of the molten protein matrix facilitates the transition from a disordered to an ordered, fibrous network, which is essential for achieving a realistic meat‐like texture (Sun et al. 2022). The schematic of a typical extruder setup is shown in Figure 1.

The cooling‐induced stabilization phase follows as the extrudate exits the barrel and enters the cooling die. This phase involves rapid temperature reduction, which solidifies the aligned protein structure by locking the molecular interactions formed during the shear stage. The cooling die not only stabilizes the fibrous structure but also shapes the product, ensuring uniformity and texture consistency. The redistribution of moisture that occurs throughout the extrudate during this phase prevents shrinkage and enhances its mechanical integrity. Improper cooling can result in the collapse or deformation of the fibrous structure, making this step critical to the quality of the final product (Nasrollahzadeh 2023; Zhang et al. 2023). Phase separation between protein and water further contributes to fibrous structure formation during wet extrusion, where the protein forms a continuous phase, while water acts as the dispersed phase, facilitating the development of anisotropy under applied shear forces. The extent of phase separation depends on the protein source, extrusion temperature, and shear intensity. Soy proteins exhibit superior phase separation properties compared to other plant proteins, such as peas and lentils, due to their robust water‐binding and gelation characteristics (Zhang et al. 2021). Additionally, innovations in cooling die design have played a pivotal role. Dynamic cooling systems enable precise temperature control during the stabilization phase, locking protein alignments into place and preventing deformation. Such advancements ensure consistency and quality in the final product. Multistage extruders, with independently controlled segments, allow simultaneous execution of hydration, denaturation, and alignment processes, offering unprecedented control over the complex transformations required for the formation of fibrous structures (Zhang et al. 2023).

Dry extrusion, while less prevalent than wet extrusion, plays a significant role in the formation of specific textures and is particularly suited to certain plant‐based products. This method operates under a similar principle to wet extrusion but with a crucial difference: the moisture content in the protein mixture is drastically reduced, usually to less than 15% (Miller 1985). This low‐moisture environment significantly affects the protein alignment process during extrusion. In dry extrusion, the lower water level reduces the plasticizing effects typically provided by moisture, forcing the proteins to align under the influence of high temperature and mechanical shear alone (Vatansever and Hall 2024). This environment creates a distinct texture in the extruded product. Specifically, the resulting texture tends to be chewier and less juicy when compared to products made via wet extrusion, mirroring certain desired qualities for specific food products like snack bars or cereals that benefit from a firmer texture. The low‐moisture content in the protein matrix during the extrusion process increases friction within the extruder barrel and provides the necessary thermal and mechanical energy to unfold protein molecules, forming a disordered but pliable matrix (Arêas 1992). Under shear forces, these unfolded proteins align and aggregate, stabilizing into layered, fibrous structures as the material exits the die, as can be seen in Figure 2. The critical variables in dry extrusion are temperature and mechanical shear. Without adequate moisture to facilitate plasticization and cooling processes, precise control of these parameters becomes critically important for successful dry extrusion. Optimizing temperature and shear levels is key to achieving the desired texture and ensuring that the protein structures align effectively with the limited amount of water available to mediate the process (Orias et al. 2002). This makes dry extrusion a specialized, yet valuable, method for achieving specific textural outcomes in producing plant‐based foods.

Soy and pea proteins (PPs) are the most used matrices for dry extrusion due to their strong thermal stability and protein functionality. Soy protein, with its high content of globular proteins, is particularly suited to creating fibrous textures, as it forms robust networks through hydrophobic interactions and disulfide cross‐links (Zheng et al. 2022). PP, while less elastic, is increasingly used in blends to enhance the sustainability and allergen‐free nature of dry‐extruded products. Recent studies also highlight the potential of incorporating functional additives such as dietary fibers and hydrocolloids during extrusion to improve water retention, elasticity, and overall texture (Marczak and Mendes 2024; Zhang et al. 2024c). The primary advantage of dry extrusion is its energy efficiency and cost‐effectiveness compared to HME (Rokey et al. 2010). The process eliminates the need for extensive drying postextrusion, making it more suitable for large‐scale production of shelf‐stable products such as granules, flakes, and crumbles. These products are particularly versatile for use in soups, sauces, and processed plant‐based meats (Ma et al. 2018). However, the lower moisture content in dry extrusion also imposes challenges. It limits the plasticity of the protein matrix, reducing molecular mobility and resulting in less anisotropic structures than wet extrusion. Consequently, dry‐extruded products are typically better suited for applications requiring coarse textures, such as ground meat analogs, rather than whole cuts (Nisov 2024).

Extrusion cooking induces key molecular transformations in plant‐based proteins, critical for fibrous texture development in meat analogs. These molecular changes are initiated and shaped by the thermal and mechanical conditions within the extruder, and they can be categorized into three interrelated processes: protein denaturation, alignment, and bonding (Verbeek and Van Den Berg 2010). Together, these transformations create a stable, fibrous structure that mimics the muscle fibers of animal meat. Protein denaturation is the first and most critical step in extrusion cooking. Under the influence of high temperatures (typically 100–180°C) and intense shear forces, the native structure of proteins is disrupted. This process unfolds protein molecules from their globular forms into extended chains, exposing their hydrophobic regions to the environment (Schmid et al. 2022). These newly exposed sites play a crucial role in subsequent molecular interactions, as they increase the potential for protein–protein and protein–water interactions. The extent of denaturation depends on factors such as the protein type, extrusion temperature, and residence time in the extruder. Soy proteins, with their high globulin content, require precise control of thermal and mechanical energy to achieve complete denaturation without degradation (Sui et al. 2021). Wheat gluten (WG), on the other hand, denatures more readily due to its inherent elasticity and responsiveness to heat (Abedi and Pourmohammadi 2021).

HME is a complex process characterized by protein aggregation and phase separation, which are pivotal for forming the fibrous texture of high‐moisture meat analogs (HMMAs). Protein denaturation and alignment during extrusion alter the protein's conformation, exposing hydrophobic regions that interact with flavor compounds, thereby influencing flavor retention and perception (Akdogan 1999). In addition to physical transformations, high temperatures in the extrusion barrel facilitate chemical reactions such as the Maillard reaction and lipid oxidation, which contribute to flavor development (Chakraborty et al. 2014). These reactions can generate desirable roasted or caramelized notes but may also produce off‐flavors if not carefully controlled. Moreover, the extrusion process modulates the matrix of raw materials, affecting the release of volatile compounds critical to flavor perception. Variations in processing conditions, such as temperature, shear rate, and feed composition, directly influence these molecular interactions and the sensory characteristics of the final product (Zhang et al. 2019). The role of proteins, starches, fibers, and other ingredients in HME for plant‐based meat, detailing how extreme conditions induce conformational changes and molecular interactions (disulfide, hydrogen, hydrophobic bonding) that form fibrous meat‐like structures. Chicken analogs with anisotropic structures (index > 1) were created using soy protein isolate (SPI), WG, and whey protein (WP) concentrate blends via HME, achieving a texture similar to cooked chicken breast through noncovalent interactions (hydrogen and hydrophobic bonding) and secondary structures (β‐sheets, α‐helix, β‐turns; Tan et al. 2024).

Recent molecular analyses show that fibrous texture in PBMA arises more from flow‐guided phase morphology—where protein‐rich continuous phases and water‐rich domains elongate under shear—and are subsequently stabilized by hydrogen bonding, hydrophobic interactions, and disulfide interchange during cooling (Ahmad et al. 2024). As the denatured proteins move through the extruder, they are subjected to mechanical shear forces, which play a pivotal role in aligning the unfolded protein molecules. These forces, generated by the screws and barrel configuration, orient the protein chains in the direction of the material flow (Day and Swanson 2013). This alignment is critical for replicating the fibrous, linear arrangement of muscle tissue of animal meat. The degree of alignment is influenced by factors such as the shear rate, screw speed, and die geometry. High shear rates and optimized screw speeds enhance molecular alignment by elongating the protein chains along the extrusion axis. Under high moisture and elevated temperature, proteins unfold and expose hydrophobic patches and thiol groups; during cooling these reactive sites promote interchain bonding that reinforces the oriented structure (Ahmad et al. 2024). Additionally, the narrow exit of the extrusion die intensifies this alignment by focusing on the flow direction. The aligned proteins serve as the structural framework for the fibrous texture, providing the anisotropy needed to mimic meat fibers (Ribeiro et al. 2024). However, the formation of a visibly fibrous, anisotropic structure, critical for mimicking muscle fibers, occurs primarily in the cooling die (Guan et al. 2024). Upon exiting the extruder, the aligned proteins encounter cooler temperatures and reduced pressure. These changes in environmental conditions promote the formation of stable chemical bonds between the protein chains, solidifying the fibrous network. Two primary types of bonding occur during this stage:

The nature and strength of these bonds are influenced by the protein composition and the cooling rate. Generally, slower cooling promotes more extensive bond formation, resulting in firmer and more cohesive textures. The inclusion of additives such as transglutaminase can further enhance cross‐linking, improving the structural stability and chewiness of the final product (Yu et al. 2025). Adding WP to pea protein isolate (PPI) enhances the formation of fibrous structures during HME. WP improves textural properties, increases disulfide bonds, and promotes β‐sheet structures, resulting in more compact aggregates and anisotropic textures, making it a promising modifier for PPI‐based meat analogs (Zhang et al. 2024c). Soybean–wheat coprecipitation protein (SWCP) produced superior fibrous textures in HME compared to blend proteins, with extrusion parameters and molecular changes significantly affecting texture formation (MacQueen et al. 2019). Faba bean protein isolate (FPI) and faba bean protein concentrate (FPC) blends can produce fibrous meat analogs using HME, with higher FPC content enhancing fiber formation. Increased FPI content improved textural properties like hardness and chewiness but reduced water absorption and fibrous organization (Kantanen et al. 2022). The addition of β‐glucan (BG) to SPI extrudates under low‐moisture extrusion enhanced disulfide and hydrogen bonding, improving oil‐holding capacity and cooking yield while reducing water solubility, which aids nutrient retention (Xiao et al. 2023). At 5% BG, the extrudates formed large molecular weight compounds stabilized by these interactions. Moreover, the modification of soy protein‐based materials with gelatin, lactose, and sucrose under low‐moisture extrusion revealed significant effects on processability and product properties. Gelatin increased specific mechanical energy (SME) but disrupted product continuity, while lactose reduced SME and promoted Maillard reactions, leading to compact, ordered structures, as confirmed by FTIR, XRD, and SEM analyses (Guerrero et al. 2012). Incorporating insoluble dietary fiber (IDF) into SPI enhances the fibrous structure and mechanical anisotropy of high‐moisture extrudates. At 10%–20% IDF substitution, a mesh‐like SPI/IDF matrix forms, promoting fibrous appearance and structural strength, while excessive IDF causes phase separation and structural collapse (Deng et al. 2023). Dry‐fractionated PP (PDF) enables sustainable, clean‐label meat analogs with 55% protein content, producing porous, softer extrudates with high oil absorption. Though requiring higher extrusion energy, PDF offers unique sensory profiles compared to neutral protein isolates (De Angelis et al. 2020).

The formation of fibrous textures in PBMAs is highly dependent on the processing conditions during texturization. The extrusion parameters, pH and ionic strength, and moisture content are key variables that influence the structural alignment and stabilization of plant proteins, ultimately dictating the quality and sensory attributes of the final product (Alam et al. 2016; Chaiyakul et al. 2009). In extrusion‐based texturization, several factors, including barrel temperature, screw speed, feed moisture content, and die shape, are critical in determining the alignment and strength of the protein network (Zhang et al. 2023). Higher temperatures during extrusion facilitate protein denaturation, exposing hydrophobic and reactive groups that promote intermolecular interactions. The application of shear forces via screw rotation aligns these denatured proteins into anisotropic structures, mimicking the fibrous nature of animal muscle. Studies have shown that increasing the screw speed enhances shear intensity, leading to improved alignment and a more uniform fibrous structure. However, excessive shear can degrade proteins, compromising texture quality (Ribeiro et al. 2024). Osen et al. (2014) highlighted that HME of PPI (83%–85% protein content) requires barrel temperatures above 120°C to induce full protein denaturation, which is critical for forming fibrous structures in meat analogs. Higher temperatures (up to 160°C) expose hydrophobic groups, promoting protein–protein interactions, and phase separation necessary for fibrous texture development. Further analysis revealed that protein denaturation, marked by a reduction in α‐helices and β‐sheets and an increase in protein aggregates, stabilizes the product's structure, demonstrating parallels between low‐ and HME in protein conformational changes. Texturization techniques, such as stretching, rolling, or folding protein dough, further enhance fibrous texture formation by physically aligning protein structures in parallel arrangements. These methods are commonly employed in downstream processing, after initial protein structuring, to refine the texture and replicate the layered properties of muscle tissue. Stretching protein dough elongates the protein network, encouraging the formation of ordered, anisotropic structures. Folding and laminating techniques, on the other hand, layer the protein matrix repeatedly, enhancing the mechanical strength and chewiness of the final product (Kinsella and Franzen 1978). Such techniques are widely used in traditional texturization methods, such as those applied to WG‐based seitan, to create chewy, fibrous meat alternatives (Singh et al. 2024).

3D printing, or additive manufacturing, is a rapidly emerging technology for creating complex fibrous structures in plant‐based proteins. Unlike traditional extrusion methods, 3D printing offers unprecedented precision in fabricating hierarchical structures, enabling the development of meat analogs that closely replicate the intricate textures of animal muscle (Dankar et al. 2018). The process involves layer‐by‐layer deposition of plant‐based protein materials, guided by computer‐aided design (CAD) models (Rayna and Striukova 2016). This technique allows for customizable shapes, textures, and even nutritional profiles in plant‐based food products. Proteins such as soy, pea, and WG are commonly used, often in combination with functional additives such as hydrocolloids and emulsifiers to improve the printability and texture of the end product. These additives enhance the flow behavior during printing and stabilize the deposited layers, ensuring a cohesive fibrous network upon solidification (Vallikkadan et al. 2023). Advances in 3D printing technology have enabled the construction of anisotropic fibrous structures that mimic the texture and mouthfeel of meat. By strategically blending proteins with starches or oils, researchers have achieved better alignment of protein molecules during printing (Dankar et al. 2018). This alignment results in hierarchical fiber assemblies that emulate the layered and fibrous structure of muscle tissue. Studies on plant‐based fish analogs have demonstrated how blending PP with corn starch and flaxseed oil enhances both printability and postprinting mechanical properties, leading to realistic fish fillet simulants (Wu et al. 2024). Despite its potential, 3D printing faces several challenges such as achieving high‐resolution printing with strong interlayer adhesion, which is difficult due to the complex interactions between protein molecules during and after deposition (Sohel et al. 2025). Additionally, the mechanical strength of 3D‐printed structures often falls short of traditional extrusion methods. To address these challenges, researchers are exploring enzyme‐assisted printing approaches, such as incorporating transglutaminase and laccase, to improve cross‐linking between protein molecules and enhance structural stability (Cheng et al. 2025).

Shear cell technology is a method that applies controlled shear forces to align and restructure protein matrices, creating textures that closely mimic the fibrous nature of meat. By carefully managing the magnitude, direction, and duration of these forces, proteins can be oriented in specific patterns to replicate the alignment of muscle fibers found in animal meats (Cornet et al. 2022). This process involves heating and shearing protein solutions or dispersions within a specific shear cell apparatus, which aligns the protein molecules into layers or fibers. The textural properties achieved through this technique are particularly effective for simulating whole‐muscle cuts, such as chicken breasts or beef steaks. The simplicity and efficiency of shear cell technology make it a viable option for scaling up production while maintaining texture consistency (Wang et al. 2023b). It is also versatile, allowing for the use of various plant‐based protein sources, including soy, pea, and WG. Recent research highlights the potential of shear cell technology to produce products with low‐fat content, appealing to health‐conscious consumers while maintaining desirable sensory attributes (Cornet et al. 2022). A study by Dinani et al. (2023) demonstrated that l‐cysteine (CYS) and l‐ascorbic acid (AA) enhance the textural properties of PPI and WG blends in high‐temperature shear cell processing, with CYS improving tensile strength and AA inducing porosity and fibrous structures, aiding in better meat analog development. Couette Cell, a process that measures a fluid's rheological properties by applying shear between two concentric cylinders, where one rotates and the other remains stationary, can produce soy‐based meat analogs with fibrous structures under mild conditions, achieving optimal anisotropy at 120°C, 30 ± 5 min, and 25 ± 5 rpm. The upscaled system enables the production of large, meat‐like structures, such as emulating chicken breast or beef, with potential for industrial application (Krintiras et al. 2016).

Electrospinning is a cutting‐edge technique originally developed in the general domain of material science. It is now being adapted for food applications, particularly in plant‐based meat production. The process uses a high‐voltage electric field to draw ultrafine fibers from a liquid protein polymer solution. The electrospinning process utilizes a high‐voltage electric field (typically 10–30 kV) to draw charged protein polymer solutions into continuous, ultrafine fibers (diameter ranging from nanometers to micrometers), creating aligned fibrous structures that can mimic meat texture (Aghababaei et al. 2024a). These fibers are then collected to form intricate fibrous networks that replicate the fine, anisotropic structure of muscle tissue (da Trindade et al. 2024a). The fine control over fiber diameter and alignment in electrospinning makes it uniquely suited to produce textures that are both tender and complex, suitable for replicating delicate meats like chicken, fish, or shellfish. Electrospinning also enables the incorporation of other functional ingredients, such as lipids or flavors, directly into the fibers, enhancing the taste and sensory profile of the final product (Coelho et al. 2021). Da Trindade et al. (2024b) demonstrated the feasibility of electrospinning polysaccharides, zein, and poly (ethylene oxide) (PEO) to create fibers for PBMA, with the optimal 90:10 zein/carrageenan ratio providing hydrophilic surfaces, excellent moisture retention, and thermal stability, crucial for achieving consistent textures. Electrospun fibers were made using zein, PEO, and PP to enhance the sensory qualities of plant‐based meats. Zein/PEO blends improve hydrophilicity and thermal stability, while incorporating PP into a zein/PEO blend (20:1) further enhances fiber properties (da Trindade et al. 2024a). These fibers mimic the texture and appearance of animal meat, offering a promising solution for creating plant‐based meats with improved sensory resemblance. MacQueen et al. (2019) developed scalable microfibrous gelatin scaffolds for cultured meat production, replicating structural features of natural muscle tissue. Using immersion rotary jet spinning, gelatin fibers were produced at high rates with tunable diameters (1.3–8.7 µm) comparable to natural collagen fibers. Cross‐linked gelatin scaffolds supported the attachment, proliferation, and alignment of bovine and rabbit muscle cells, promoting structural and mechanical properties akin to meat, though lacking mature contractile architecture. Challenges remain in scaling this technique for industrial applications due to its complexity and reliance on high‐energy inputs. Recent advances in process efficiency and equipment design aimed at addressing these limitations are making electrospinning a promising avenue for future development. Table 1 summarizes the principles of key PBMA production techniques, including HME, 3D printing, shear cell technology, electrospinning, and others. The table highlights their relative advantages and limitations, providing a clearer understanding of their applications and challenges in plant‐based meat production. Although emerging technologies have demonstrated strong potential for generating aligned structures at the lab scale, a critical evaluation of their scalability and energy efficiency is required before they can be considered as viable complements to extrusion in industrial PBMA production. These technologies offer promising avenues for achieving structural precision and customization; however, their limited throughput and need for material standardization present significant barriers to commercial adoption.

Soybean is an easily available and extensively used ingredient in meat analogs worldwide (Ishaq et al. 2022). It is available in three primary forms, including soy flour, soy protein concentrates (SPCs), and SPIs with approximate protein contents of 50%, 70%, and 90%, respectively (Webb et al. 2023). The extractable soy proteins are classified into four protein categories: 2S, 7S (β‐conglycinin, around 40% of total protein), 11S (glycinin, around 30% of total protein), and 15S according to their sedimentation coefficients. β‐Conglycinin (equivalent to vicilin in other legumes) and glycinin (equivalent to legumin in other legumes) fractions represent around 80% of the soy proteins (Kyriakopoulou et al. 2021). The functional properties of soy ingredients are determined by the type and ratios between different proteins and the presence of additional compounds such as carbohydrates (Kyriakopoulou et al. 2021). Both vicilin and legumin are salt‐soluble. Vicilin, also referred to as 7S globulin, is a trimeric protein typically composed of three subunits, each with a molecular weight ranging from 50 to 70 kDa, resulting in a native trimer complex of approximately 150–210 kDa (Qi et al. 2011). It is relatively heat‐labile, less prone to forming disulfide bonds, and has lower cysteine and methionine content, which limits its structural rigidity and network‐forming ability. Legumin, also known as 11S globulin, forms a hexameric complex made up of six subunit pairs (acidic and basic chains) linked via disulfide bonds. Each subunit pair is ∼60 kDa, yielding a total complex of around 320–360 kDa (Staswick et al. 1984). Legumin is more heat‐stable, has a higher sulfur amino acid content, and is capable of forming intermolecular disulfide bonds, contributing to stronger gelation and fibrous structuring under thermal processing. Both proteins exhibit pH‐dependent solubility, with isoelectric points (pI) in the range of 4.5–5.0, and show limited solubility near their pI (Renkema et al. 2001). However, legumin is a smaller fraction of the protein content in soy; it contains about 20 sulfide groups, allowing for disulfide bonding and a strong ability for texturization. Therefore, the ratio of these proteins is very important to the protein functionality in texturized vegetable proteins (Kyriakopoulou et al. 2021). Thus, despite the lower concentration of legumin compared to vicilin in soy protein, it plays a major role in the texturization of protein via a greater number of sulfide groups. Soybean protein has been designated the maximum possible score of 1.0 for being identical to animal protein on the scale of protein digestibility corrected amino acid score (PDCAAS; Ishaq et al. 2022). Owing to good nutritional composition and the ability to regulate textural properties of the final product, and satisfactory functional qualities such as the ability to absorb water and oil and its emulsifying properties, soy proteins are one of the most widely used and researched components of PBMA (Benković et al. 2023; Ishaq et al. 2022). Due to the excellent features of soy, it is often used as a standard or benchmark to compare different protein materials (Zahari et al. 2022). Recent advancements in PBMAs have focused on improving the textural and functional properties of SPC‐based high‐moisture meat analogs (SPC‐HMMA). A novel study by Gulzar et al. (2025b) integrated artificial intelligence (AI) and genetic algorithms (GA) to optimize the texture of SPC‐HMMA, aiming to mimic the characteristics of traditional chicken and beef. By adjusting sorbitol concentrations and moisture levels, the texture of SPC‐HMMA was significantly modified.

Peas contain 20%–30% protein, 50%–70% carbohydrates, and fiber, with composition varying by genotype and environment (Lu et al. 2020). They are a rich source of lysine and threonine, essential for human nutrition (Johansson et al. 2021), and provide minerals (Fe, P, Mg), vitamins, and lipids, enhancing their nutritional value (Benković et al. 2023). PP comprises four protein classes including globulin (55%–65%), albumin (18%–25%), prolamin (4%–5%), and glutelin (3%–4%; Lu et al. 2020). Within the globulin fraction, the primary proteins are vicilin (43%), a 7S globulin that contributes to foaming and emulsifying properties, and legumin (28%), an 11S globulin that enhances gelation and textural strength. Peas also contain convicilin, unique to this legume, which has a higher sulfur content than vicilin, aiding in disulfide bond formation crucial for textured plant proteins (Webb et al. 2023). PP exhibits several technofunctional properties, such as water‐ and fat‐binding abilities, making it an effective binder in meat analogs. It has moderate gelling capacity, though inferior to soy, and good emulsifying and foam‐stabilizing properties, making it versatile in food applications (Lam et al. 2018; Lu et al. 2020). High water‐holding capacity and solubility allow PP to form emulsions and protein networks, crucial for developing meat analogs (Lee et al. 2023). PP has been successfully structured using HME and shearing to create meat analog fibers (Osen et al. 2014; Schreuders et al. 2019). However, pea‐based structures are weaker than soy‐based ones, necessitating the use of hydrocolloids or structural agents to improve textural properties (Batista et al. 2005).

WG is composed primarily of two protein fractions: gliadin, the major prolamin, and glutenin, the major glutelin. Gliadins are monomeric proteins with molecular weights of 30,000–60,000, characterized by their ability to form intrachain disulfide bonds and impart viscosity to gluten (Peng et al. 2023; Veraverbeke and Delcour 2002). Glutenins are high molecular weight (up to 20 million) polymeric proteins that form interchain disulfide bonds, contributing to the elasticity and strength of gluten (Gianibelli et al. 2001; Peng et al. 2023; Sissons et al. 2005). Together, gliadin and glutenin form a cohesive, viscoelastic matrix when mixed with water, critical for both bakery, and meat analog applications (Webb et al. 2023). Cross‐linking via disulfide bonds between these proteins, particularly under heating and mechanical deformation, results in the formation of a robust 3D protein network (Peng et al. 2023). Gluten's ability to form extensible and elastic films under deformation makes it ideal for producing fibrous textures in plant‐based meat products (Sissons et al. 2005). Its water retention and swelling properties enhance cooking stability and slicing characteristics, reducing cooking losses and ensuring a consistent texture (Peng et al. 2023). Gluten contributes to the swelling and cohesiveness of the protein matrix, enabling it to be stretched and aligned under shear flow in the cooling die during extrusion. This behavior helps mimic the fibrous texture of muscle meat in PBMA (Krintiras et al. 2015). HME processes utilize gluten's viscoelastic properties to transform protein matrices into fibrous structures. This is achieved through mechanical stretching and deformation, which aligns the protein molecules to produce anisotropic textures similar to real meat (Krintiras et al. 2015). The polymerization of gluten proteins under extrusion conditions, driven by disulfide bond formation and rearrangement, creates a continuous network essential for meat‐like textures (Kyriakopoulou et al. 2021). Gluten also functions as a binder, ensuring that the fibers are held together in the final product, contributing to the chewiness and elasticity desired in plant‐based meat (Kumar et al. 2017; Zhang et al. 2021).

Factors like temperature, water content, and shear force significantly influence gluten polymerization and fibrous structure development. Extrusion temperatures between 130 and 140°C promote anisotropic structures by enhancing protein alignment and cross‐linking, while temperatures above 140°C may lead to degradation (Emin et al. 2017). Lower temperatures (< 80–90°C) result in weaker network formation, with reduced polymerization and fibrous characteristics, leading to more isotropic textures (Emin et al. 2017). Optimal water content (20%–40%) enhances gluten's viscoelastic properties, promoting fiber formation and mechanical strength. Water levels below 20% lead to dense, brittle structures due to restricted protein mobility, while exceeding 40% reduces cross‐linking efficiency, resulting in a weaker gluten network (Emin et al. 2017). Shear forces during extrusion promote fibrillation and fiber orientation, enhancing meat‐like textures. Optimal shear conditions (∼150 rpm screw speed) result in the best fibrous structure, whereas excessive shear (> 200 rpm) can degrade the network, leading to a gel‐like texture instead of meat‐like fibers (Zhang et al. 2022). Low lipid concentrations (< 2%) act as plasticizers, moderating protein aggregation and enhancing hydrophobic interactions, which helps maintain gluten elasticity and flexibility. However, lipids also reduce excessive cross‐linking, preventing a dense, overly rigid structure, thereby influencing the final texture (Chen et al. 2021). When combined with soy protein, WG enhances fibrous structure formation by acting as the continuous phase in a two‐phase system. The interactions between gluten and soy protein influence water distribution and texture development, but structural integrity depends on processing conditions (Peng et al. 2023).

Rice protein can be derived from defatted rice bran, a byproduct of rice milling, which contains 15.4% protein (Amagliani et al. 2017). Rice protein primarily comprises glutelins (80%), followed by prolamins (4%), globulins (12%), and albumins (2%–4%) (47). Glutelins are hydrophobic and held together by disulfide bonds, making them structurally stable in acidic or alkaline solutions (Amagliani et al. 2017). Rice protein is hypoallergenic, making it ideal for sensitive populations such as infants and the elderly (Zheng et al. 2023). It also boasts a high biological value (77%) compared to soy protein (67%) and comparable to shrimp protein (Li et al. 2019b). Rice protein is considered superior to proteins from wheat and corn and comparable to oats, with an amino acid composition that surpasses casein and SPI (Han et al. 2015). The functional properties of rice protein, such as solubility, foaming, emulsifying, gelling, water‐holding, and oil‐holding capacities, are critical for its food applications. However, its poor solubility negatively affects these properties (Amagliani et al. 2021). Several modification methods, such as chemical methods, enzymatic methods, physical methods, have been explored to improve solubility. Despite these advances, combining rice protein with other protein systems may yield better functional outcomes (Zheng et al. 2023). Technological advancements have enabled rice protein to be incorporated into meat analogs, enhancing their nutritional value. Combining rice protein isolate with SPI has produced improved meat analogs. Qiu et al. (2023) reported that incorporating rice protein enhances 3D printing capabilities for creating meat‐like shapes and textures. Unlike soy protein, rice protein has a milder flavor, lacks an unpleasant taste, and is both hypoallergenic and hypocholesterolemic (Detchewa et al. 2022). It supplements methionine, an amino acid often deficient in soy protein, while lysine, the limiting amino acid in rice protein, is abundant in soy protein, making it nutritionally complementary. Consuming these proteins together can help in preventing amino acid deficiencies (Lee et al. 2022b). Rice protein has a lower water‐holding capacity compared to soy protein, about one‐third of that of soy protein. Despite this limitation, rice protein has potential as an ingredient for meat analogs (Lee et al. 2022a). The integration of rice protein into meat analogs is a promising yet underexplored area. Its nutritional and functional properties, particularly when combined with soy protein, make it a viable alternative for producing meat analogs with improved amino acid profiles. Further research and technological innovations could unlock their full potential, addressing challenges related to solubility and industrial scalability.

Lentil proteins are emerging as a promising ingredient in plant‐based meat alternatives due to their excellent nutritional value, functional properties, and sustainability (Boye et al. 2010). Lentil proteins enhance the nutritional profile of plant‐based formulations, especially when combined with other sources like pea or rice protein to achieve a complete amino acid profile (Boye et al. 2012). Lentil proteins exhibit desirable functional properties, including high water‐holding capacity, gelation ability, and emulsification properties, which are critical for mimicking the fibrous, juicy texture of meat (Karaca et al. 2011). During extrusion and shear cell processing, lentil proteins can form cohesive, anisotropic structures that replicate the texture of whole‐muscle cuts, such as chicken or fish (Dekkers et al. 2018). Although challenges like solubility and flavor masking remain, advances in processing technologies and ingredient engineering are unlocking the potential of lentil proteins as a versatile and eco‐friendly alternative in the growing market for PBMA (Asgar et al. 2010). The technofunctional properties of lentil proteins include a solubility range that varies depending on processing conditions. Solubility is highest under neutral to alkaline conditions, reaching 55%–65% at pH 7.0 and improving further at pH 9. However, it is significantly reduced at pH 4–5, near the isoelectric point, leading to protein aggregation and precipitation (Aghababaei et al. 2024b). Lentil proteins exhibit an emulsification activity index (EAI) between 90.3 and 123.3 m²/g, with an average value of 93.3 ± 0.2 m²/g, depending on processing conditions. These properties contribute to their role in stabilizing emulsions for plant‐based formulations (Joshi et al. 2011). Lentil proteins exhibit a water absorption capacity ranging from 2.8 to 4.1 g/g protein and an oil absorption capacity of 1.6–2.9 g/g protein, depending on processing conditions and protein fractionation methods. These functional properties influence texture and mouthfeel in plant‐based formulations (Chang et al. 2023). Lentil proteins require relatively low concentrations (8%–14% w/v) to form gels upon heating, indicating stronger gelling ability compared to pea, chickpea, and soy proteins. (Jarpa‐Parra et al. 2014). While these concentrations are lower than those typically required for PBMAs, this property makes lentil proteins advantageous as thickening ingredients to modulate food texture at lower protein levels.

Chickpea proteins are increasingly recognized as a versatile and nutritionally rich option for plant‐based foods (Boye et al. 2010). With a protein content ranging from 17% to 22% in raw chickpeas and higher concentrations in isolated forms, chickpea proteins offer excellent digestibility and a favorable balance of essential amino acids, particularly lysine (Boukid 2021). These properties make them a valuable ingredient for complementing other plant proteins, such as wheat or pea, in achieving a complete amino acid profile in meat substitutes (Day 2013). Chickpea proteins excel in their emulsification (50–75 m²/g), water‐binding (2.9–4.5 g/g protein), and gelation (12%–16% w/v) properties, making them essential for cohesive textures in plant‐based formulations (Pennells et al. 2024). Their emulsifying capacity stabilizes fat and water mixtures, contributing to the juicy and tender textures often associated with traditional meat products (Makri et al. 2005). Chickpea protein gels are heat‐induced, forming stable networks that mimic the fibrous structure of meat, especially when processed via HME or shear cell technology (Dekkers et al. 2018). These attributes make chickpea proteins suitable for applications in burgers, nuggets, and even whole‐muscle analogs (Boukid 2021). One notable advantage of chickpea proteins is their mild flavor profile compared to other plant proteins, such as soy or pea. This characteristic reduces the need for extensive flavor masking, making chickpea proteins ideal for clean‐label formulations (Boye et al. 2010). Beyond their functional roles, chickpeas are hypoallergenic and non‐GMO, broadening their appeal to health‐conscious and allergen‐sensitive consumers (Boukid 2021). From a sustainability perspective, chickpeas are a low‐impact crop with moderate water requirements and the ability to fix nitrogen, contributing to soil health (Nemecek et al. 2008). These attributes position chickpea proteins as an environmentally friendly alternative to traditional meat and other plant protein sources (Tharanathan and Mahadevamma 2003). Despite their advantages, chickpea proteins can exhibit lower solubility under certain conditions, which may require optimization through advanced extraction and processing methods (Joshi et al. 2011). Their application in PBMA is expanding, driven by innovations in protein structuring technologies and their growing consumer demand for sustainable, nutrient‐rich options (Dekkers et al. 2018). Boukid (2021) highlighted chickpea proteins as a promising alternative protein source, emphasizing their nutritional value, essential amino acid content, and digestibility. Their bland flavor, neutral taste, and light color, combined with functional properties, make them suitable for diverse food applications, including PBMA, noodles, breads, and sausages, with hydrolysates showing potential for broader use as functional ingredients (Boukid 2021). Zahari et al. (2023) found that HMMA made with hempseed protein concentrate (HPC) and WG at a 90:10 ratio showed superior textural properties, while 50:50 blends of HPC with WG or chickpea protein concentrate (CPC) provided balanced physicochemical and sensory qualities under optimized extrusion conditions.

Fava bean proteins are gaining recognition as a sustainable and functional ingredient for PBMA, offering a unique combination of nutritional benefits and versatile functional properties (Boye et al. 2010). With a protein content ranging between 25% and 30%, fava beans are an excellent source of essential amino acids, particularly lysine, which complements other plant proteins like WG or PP (Boye et al. 2010). Their high‐protein concentration makes FPIs and concentrates suitable for formulating meat analogs with balanced amino acid profiles (Alonso‐Miravalles and O'Mahony 2018). Fava bean proteins excel in their water‐holding capacity (2–4 g/g protein) and emulsification properties, with an emulsifying activity index (45.6–67.8 m²/g) and emulsion stability index (55%–75%). These properties are critical for replicating the juiciness and cohesiveness of traditional meat products. During HME, fava bean proteins form heat‐induced gels and fibrous structures, closely mimicking the texture of muscle tissue (Dekkers et al. 2018). Their gelation ability enables the development of firm and elastic textures, making them suitable for a range of applications, including burgers, sausages, and whole‐muscle cuts (Huamaní‐Perales et al. 2024). Furthermore, enzymatic treatments can enhance the textural integrity of fava bean‐based products, improving their chewiness and mechanical strength (Eckert et al. 2019). Advancements in extrusion and shear cell technology, along with innovative ingredient engineering, are enhancing the use of fava bean proteins for improved texture, flavor, and nutrition (Dekkers et al. 2018). do Carmo et al. (2021) found that FPC can produce meat analogs with optimal firmness and elasticity under HME at 130–140°C, a water‐to‐feed ratio of 4, and a feed rate of 11 rpm, with moisture content being the most influential factor.