Current Processing Technologies and Challenges in Hybrid Meat Production

Abstract

Hybrid meat products, i.e., the combination of animal proteins with plant, microbial, algal or cultured ingredients, are becoming increasingly important as a pragmatic approach to reducing the environmental and health impact of conventional meat while retaining familiar sensory properties. This review highlights that moderate substitution rates (20–50%) can maintain or improve texture, juiciness and nutritional balance, whereas higher incorporation rates often lead to off-flavours, colour changes and texture issues. Advances in extrusion, co-processing and protein structuring have enabled increasingly sophisticated formulations. Studies show that the choice of ingredients has a strong influence on the sensory results. For example, faba beans, rice by-products or insect proteins are more acceptable at low to moderate levels, while excessive use of pulses or texturised proteins can produce beany or earthy notes. Nutritional improvements, such as more fibre and healthier fatty acid profiles, are possible but require careful optimisation. Consumer acceptance is increasing, particularly among flexitarians, but remains dependent on sensory performance, familiarity, and perceived health benefits. Ongoing obstacles include unclear regulatory requirements, high production costs and scalability issues. Future progress will require optimisation of ingredient blends, robust life cycle assessments to verify sustainability claims and transparent communication to increase consumer confidence.

1. Introduction

Meat remains a central part of the global diet due to its high protein density, bioavailable iron, vitamin B12 and well-known sensory appeal. Historically, meat has been a cornerstone of the human diet for over 2.6 million years [1], evolving from hunted sources to domesticated animals such as poultry, pigs and cattle. However, growing population pressure, which is expected to reach 9.7 billion people by 2050 [2], will lead to an increase in food demand of up to 60% [3] and put unsustainable pressure on global food systems.

At the same time, high meat consumption is associated with chronic diseases such as obesity, cancer and cardiovascular disease [4], leading to recommendations to reduce, but not eliminate, meat consumption [5]. Health concerns aside, livestock farming contributes significantly to environmental degradation as it is a major contributor to global greenhouse gas emissions and land degradation [6,7]. In addition to this, the water footprint has emerged as a crucial dimension of the sustainability of food systems. Livestock farming is very water-intensive. Global evaluations show that beef production requires an average of more than 15,000 litres of water per kilogramme, while the figures for pork, poultry and, in particular, plant proteins are significantly lower [8]. This has triggered a shift in diets towards more plant-based diets such as vegetarianism, veganism and flexitarianism, particularly in high-income countries [9,10].

The market response to this change has been remarkable. The global plant-based meat market was estimated at USD 7.2 billion in 2023 and is expected to reach over USD 37.5 billion by 2030 [11]. Plant-based meat analogues (PBMAs) are defined as food products designed to mimic the appearance, flavour, texture and nutritional profile of conventional meat and are typically made from plant-based ingredients such as soy, pea, wheat or mycoprotein. However, despite their environmental and ethical appeal, plant-based meat analogues face significant sensory and functional hurdles. Key limitations include incomplete amino acid profiles, low digestibility, off-flavours and inadequate texture [12,13]. Many PBMAs, despite their initial popularity, have experienced declining retail performance in key markets such as the US, mainly due to issues with flavour, texture and high cost [14]. As a result, interest in cultured meat, also known as lab-grown or cell-based meat, has increased. This technology involves growing animal cells in controlled environments, such as bioreactors, to replicate the structure and composition of conventional meat without the need to slaughter animals. Cultured meat offers promising benefits in terms of animal welfare, reduced land use and potentially lower greenhouse gas emissions [15,16]. However, it also faces significant challenges, including high production costs, limited scalability, regulatory uncertainties and consumer hesitation due to unfamiliarity and perceived unnaturalness [15]. Although these costs are currently high, recent analyses indicate a trend towards a reduction. For example, it has been estimated that large-scale production of cultured meat under optimised conditions could reach around $63 per kg [17]. In addition, other emerging protein sources such as fermentation-derived proteins and edible insects are also being explored due to their favourable sustainability and nutritional properties, although their widespread adoption remains limited by cultural acceptance and formulation challenges [18,19].

In response to the limitations of both conventional meat and plant-based alternatives, a new class of products has emerged—hybrid meat. Also known as dual-protein foods [20], hybrid meat products combine animal ingredients with plant, fungal, microbial or cultured protein sources. The aim is to combine the nutritional density and sensory familiarity of meat with the sustainability and functional benefits of alternative proteins [21,22]. These products, which typically consist of 25–50% non-meat ingredients, retain the familiar formats of burgers, sausages and nuggets while offering a lower environmental footprint and an improved nutritional profile [23]. This balanced positioning makes them particularly attractive to flexitarian consumers, who now represent a significant and growing segment worldwide.

The composition of hybrid meat products varies greatly depending on the target application and sensory expectations. Common non-meat ingredients include texturised plant proteins (e.g., soy, pea), mycoproteins, microalgae, edible insects and new precision-fermented proteins [24,25]. Among these, texturised soy protein (TSP) remains one of the most widely used proteins due to its availability and cost-effectiveness and can replace up to 50% of meat without significantly affecting water holding capacity, juiciness or palatability [20,26]. Depending on the formulation, these proteins are usually used in powdered, hydrogenated or texturised form.

Manufacturers use a range of processing technologies to produce hybrid meat. While blending, emulsification, and thermal setting are often sufficient thanks to the binding and structuring properties of animal proteins, more advanced techniques are increasingly used when a meat-like fibre structure is desired. These include high moisture extrusion (HME), which is widely used for plant meat analogues and is now also being explored for hybrid systems. HME enables the alignment of proteins into anisotropic, meat-like textures and can also enable the incorporation of binders, fats and flavourings [27,28]. Additional innovations such as co-extrusion, 3D printing and textured layering offer further opportunities to improve texture, marbling and product realism, particularly in more sophisticated hybrid formats [29,30].

Despite their potential, hybrid meat products face several barriers to broader adoption. On the consumer side, perceptions of unnaturalness, excessive processing and unfamiliar flavours persist, although others see hybrids as a healthier and more sustainable middle ground [31,32]. From a nutritional perspective, concerns remain regarding the completeness of amino acids, bioavailability and whether specific formulations can be categorised as ultra-processed foods [33,34]. Furthermore, the hybrid meat category still lacks clear regulatory definitions, standardised labelling and market differentiation, factors that are essential for consumer confidence and industry alignment [35,36]. Although hybrid meat represents an important bridge to more sustainable food systems, its success depends not only on technological capabilities, but also on effective communication, regulation and product design.

This review aims to provide a comprehensive overview of the development of hybrid meat, covering definitions and classifications, ingredient sourcing and processing technologies, sensory and nutritional attributes, and consumer acceptance. By analysing current literature and market data, this paper seeks to clarify conceptual ambiguities, identify scientific and commercial bottlenecks, and provide strategic directions to advance hybrid meat as a viable component of sustainable global food systems.

2. Definitions and Classification of Hybrid Meat

The hybrid meat category refers to foods that combine animal ingredients with non-animal protein sources such as plant ingredients, microbial biomass, fermentation-derived compounds, insects, algae or cultured animal cells [21,36]. These formulations aim to maintain the sensory familiarity and nutritional benefits of meat while improving sustainability and affordability.

While there is no universally accepted regulatory definition, hybrid meat is typically characterised by the partial (25–50%) replacement of conventional meat with one or more alternative protein sources [23,37]. There are several classification options for hybrid meat products in the literature, the most common of which are listed below. Understanding these multidimensional classifications helps structure R&D pipelines and informs product labelling, marketing and regulatory review.

2.1. Classification by Ingredient Source

Hybrid meat products can be categorised according to the type and combination of proteins they contain:

• Plant-meat hybrids: these combine conventional meat with plant proteins such as soy, pea, wheat gluten or pulses. Their purpose is to reduce the meat content while maintaining familiarity and improving the health or sustainability profile [38]. Texturised vegetable proteins (TVPs), particularly soy-based, are often used in this format due to their structural compatibility and cost-efficiency [26,29].
• Fermentation-enriched hybrids: These include microbially derived ingredients such as mycoprotein, precision fermented heme, or yeast-derived fats. They are used either to supplement plant–meat mixtures or to improve flavour and nutritional value in products with a lower animal content [39,40].
• Insect–meat hybrids: Products that combine edible insect proteins (e.g., from mealworms or crickets) with meat are gaining traction due to their high protein density and low environmental impact, although regulatory and consumer barriers exist [18];
• Algal or fungal-based hybrids: Spirulina, Chlorella and fungal proteins (e.g., Fusarium venenatum) are used in meat blends due to their micronutrient profile and sustainability benefits [24,36].
• Cultivated meat hybrids: In this emerging category, ex vivo cultured animal cells are integrated into structured plant matrices to reduce cell mass requirements while increasing realism. These systems are still largely pre-commercial, but are promising for whole-cut analogues [41,42].

2.2. Classification by Structure and Format

In addition to the origin of the ingredients, hybrid meats can also be categorised by their physical architecture and formulation strategy, which influence both processing requirements and consumer experience:

• Blended hybrids: Homogeneous mixtures where plant and meat ingredients (fine or coarse) are ground and integrated into a single-phase matrix (e.g., hybrid sausages or burgers). These formats are commonly used due to the ease of formulation and processing [35].
• Layered or stratified hybrids: Multiphase systems that combine layers of meat and plant-based gels or emulsions. Although this allows the ingredients to be separated, the structural complexity increases [18].
• Scaffolded hybrids: Structured products in which cultured muscle or fat cells are applied to plant or fungal scaffolds that mimic whole muscle meat. These products are at the frontier of hybrid innovation and require tissue engineering and controlled architecture [42,43].

2.3. Classification by Ingredient Role

Hybrid formulations can also be differentiated according to the functional contribution of the individual components:

• Hybrid products with structural agents: Vegetable proteins (e.g., soy isolate, wheat gluten) are used to mimic muscle fibres and bind moisture [38].
• Hybrid products with flavour enhancers: heme obtained by fermentation, cultured fats or umami-rich compounds are used to enhance meat flavour [39,41].
• Hybrid products with nutritional fortifiers: Microbial lipids, algae or insect proteins provide omega-3 fatty acids, B12, iron and fibre [19,24].

3. Processing Technologies in Hybrid Meat Production

Hybrid meat production encompasses a wide range of processing strategies aimed at integrating animal and alternative protein ingredients such as plant proteins, algae, fungi, microbial biomass and cultured cells into structurally cohesive, nutritionally balanced and sensorially appealing food products. In contrast to conventional processed meat or fully plant-based analogues, hybrid products combine ingredients with very different moisture content, thermal stability, protein structures and sensory profiles. As a result, the technologies used to produce them are neither standardised nor fully optimised. While extrusion remains the predominant processing platform, continued advances in ingredient development, precision fermentation and scaffold development are enabling increasingly sophisticated hybrid formulations. These innovations are gradually transforming hybrid meat from a niche strategy into a versatile and transformative food category.

Table 1 provides a consolidated overview of hybrid meat systems, categorised by protein source, with detailed information on representative ingredients, processing and structuring technologies, key operational parameters, functional roles, application examples, and associated challenges or limitations.

Hybrid meat production encompasses a spectrum of overlapping and modular processes, ranging from the simple blending of hydrated, dry-extruded texturised vegetable proteins with conventional meat to high-moisture co-extrusion of multiple protein types, the incorporation of microbial and fungal biomass and even the experimental layering of cultured animal tissue. Each protein source comes with specific physical and chemical constraints that affect process design, ingredient compatibility and product performance. The most common and some novel processing technologies are listed below.

3.1. Blending Meat with Texturized Vegetable Proteins (TVPs)

The most basic and historically widespread strategy for hybrid meat is to blend conventional meat with texturised vegetable proteins (TVPs). This approach is often used to increase the meat content, reduce production costs and improve the nutritional profile of processed meat products such as burgers, sausages, meatballs and patties [44,45]. TVPs are typically produced by low moisture extrusion (LME), also known as dry extrusion. In this process, defatted vegetable protein flours, mainly derived from soy, wheat or pea, are subjected to high temperature and mechanical shear at low water content (20–30%), resulting in shelf-stable, porous, fibrous granule that mimics the texture of cooked minced meat [27,46].

After rehydration, TVPs are incorporated into meat matrices in proportions ranging from 15% to 50%, depending on the desired sensory, nutritional and economic parameters [20,26]. Among plant proteins, textured soy protein (TSP) is most commonly used in commercial hybrid formulations due to its neutral flavour, favourable amino acid profile and excellent water and fat binding capacity, which helps to maintain juiciness and improve cooking performance [36]. Blending soy- or pea-based TVPs with meat has been shown to significantly reduce saturated fat and cholesterol content while maintaining flavour, texture and colour acceptable to the consumer [29,47].

However, the success of these formulations depends on the homogeneous integration of TVPs into meat systems. At higher substitution levels (>30%), challenges such as phase separation, rubbery or grainy mouthfeel and reduced protein digestibility can occur, requiring careful selection of particle size, hydration protocols and functional additives such as hydrocolloids or phosphates to optimise textural compatibility [27,45].

Table 1. Technology and source overview of hybrid meat systems with processing parameters and key challenges.

Protein Source	Representative Sources	Processing/Structuring Technologies	Key Processing Parameters	Functional Role	Example Applications	References	Challenges/Limitations
Plant-based proteins	Soy protein isolate/concentrate, textured pea protein, faba bean concentrate, wheat gluten, rice bran, hemp seed meal	Low-moisture extrusion (LME), high-moisture extrusion (HME), shear cell structuring, blending and comminution, hydrocolloid-assisted structuring	LME: 20–35% moisture, 120–160 °C barrel temp; HME: 45–70% moisture, 90–140 °C; Shear cell: 60–70 °C for 15–30 min at 10–20 rpm; Inclusion 5–50%	Enhances texture and WHC, partial replacement of meat protein, improves amino acid profile, supports fibrous structure	Burgers, sausages, nuggets, deli slices	[48,49,50,51]	Off-flavours (beany, grassy), colour changes at high inclusion; possible antinutrients; reduced binding strength above 50% replacement
Fungal and algal proteins	Mycoprotein (Fusarium venenatum), filamentous fungi, Spirulina, Chlorella	Submerged fermentation, gelation, freeze–thaw texturing, incorporation into emulsions	Fermentation: 26–30 °C, pH 6–6.5, 48–72 h; Freeze–thaw: −18 °C to +4 °C for 3–5 cycles; Inclusion 5–30%	Adds dietary fibre, improves umami, stabilises emulsions, increases protein diversity	Hybrid patties, meatballs, frankfurters	[52,53,54]	Regulatory uncertainty for novel strains; sensory acceptance issues; colour inconsistency
Insect proteins	Tenebrio molitor larvae powder/protein, cricket flour	Defatting, milling, enzymatic hydrolysis, incorporation into meat matrices	Defatting: hexane or mechanical pressing at 50–60 °C; Hydrolysis: 50 °C, pH 7–8 for 1–3 h; Inclusion 2–15%	Boosts protein quality, adds micronutrients (iron, zinc), modifies texture at low levels	Hybrid frankfurters, sausages, meatballs	[54,55]	Consumer aversion in some markets; allergenicity; potential microbial load if underprocessed
Cultivated animal cells	Cultured bovine myocytes, adipocytes	Scaffold-based tissue engineering, co-culture with plant scaffolds, layered assembly	Cell culture: 37 °C, 5% CO2, serum-free medium; Differentiation: 5–10 days; Post-harvest layering with plant matrix	Mimics whole muscle structure, authentic meat flavour and juiciness	Cultivated–plant hybrid steaks, deli slices	[42,43]	High production costs; scalability issues; regulatory approval hurdles; consumer perception as “unnatural”
Microbial biomass	Brewer’s spent yeast, single-cell protein (SCP)	Mechanical cell disruption, ultrasound-assisted processing, thermal treatment	Ultrasound: 20–40 kHz, 5–15 min, 40–60 °C; Pasteurisation: 72–80 °C for 15–30 s; Inclusion 3–10%	Improves binding, water retention, adds B-vitamins, alters flavour profile	Beef patties, chicken nuggets	[56,57]	Bitter/yeasty notes; cell wall digestibility; sourcing consistency
Oilseed proteins	Pumpkin seed protein, sunflower protein, canola protein	Wet extrusion, cold pressing, partial deoiling	Extrusion: 40–60% moisture, 100–140 °C; Cold pressing: ≤50 °C; Inclusion 5–20%	Improves lipid profile, adds PUFA, modifies texture	Hybrid sausages, burger patties	[40,53]	Risk of erucic acid (e.g., in pumpkin seed protein); oil separation; flavour masking needed

Table 1. Technology and source overview of hybrid meat systems with processing parameters and key challenges.

Protein Source	Representative Sources	Processing/Structuring Technologies	Key Processing Parameters	Functional Role	Example Applications	References	Challenges/Limitations
Plant-based proteins	Soy protein isolate/concentrate, textured pea protein, faba bean concentrate, wheat gluten, rice bran, hemp seed meal	Low-moisture extrusion (LME), high-moisture extrusion (HME), shear cell structuring, blending and comminution, hydrocolloid-assisted structuring	LME: 20–35% moisture, 120–160 °C barrel temp; HME: 45–70% moisture, 90–140 °C; Shear cell: 60–70 °C for 15–30 min at 10–20 rpm; Inclusion 5–50%	Enhances texture and WHC, partial replacement of meat protein, improves amino acid profile, supports fibrous structure	Burgers, sausages, nuggets, deli slices	[48,49,50,51]	Off-flavours (beany, grassy), colour changes at high inclusion; possible antinutrients; reduced binding strength above 50% replacement
Fungal and algal proteins	Mycoprotein (Fusarium venenatum), filamentous fungi, Spirulina, Chlorella	Submerged fermentation, gelation, freeze–thaw texturing, incorporation into emulsions	Fermentation: 26–30 °C, pH 6–6.5, 48–72 h; Freeze–thaw: −18 °C to +4 °C for 3–5 cycles; Inclusion 5–30%	Adds dietary fibre, improves umami, stabilises emulsions, increases protein diversity	Hybrid patties, meatballs, frankfurters	[52,53,54]	Regulatory uncertainty for novel strains; sensory acceptance issues; colour inconsistency
Insect proteins	Tenebrio molitor larvae powder/protein, cricket flour	Defatting, milling, enzymatic hydrolysis, incorporation into meat matrices	Defatting: hexane or mechanical pressing at 50–60 °C; Hydrolysis: 50 °C, pH 7–8 for 1–3 h; Inclusion 2–15%	Boosts protein quality, adds micronutrients (iron, zinc), modifies texture at low levels	Hybrid frankfurters, sausages, meatballs	[54,55]	Consumer aversion in some markets; allergenicity; potential microbial load if underprocessed
Cultivated animal cells	Cultured bovine myocytes, adipocytes	Scaffold-based tissue engineering, co-culture with plant scaffolds, layered assembly	Cell culture: 37 °C, 5% CO2, serum-free medium; Differentiation: 5–10 days; Post-harvest layering with plant matrix	Mimics whole muscle structure, authentic meat flavour and juiciness	Cultivated–plant hybrid steaks, deli slices	[42,43]	High production costs; scalability issues; regulatory approval hurdles; consumer perception as “unnatural”
Microbial biomass	Brewer’s spent yeast, single-cell protein (SCP)	Mechanical cell disruption, ultrasound-assisted processing, thermal treatment	Ultrasound: 20–40 kHz, 5–15 min, 40–60 °C; Pasteurisation: 72–80 °C for 15–30 s; Inclusion 3–10%	Improves binding, water retention, adds B-vitamins, alters flavour profile	Beef patties, chicken nuggets	[56,57]	Bitter/yeasty notes; cell wall digestibility; sourcing consistency
Oilseed proteins	Pumpkin seed protein, sunflower protein, canola protein	Wet extrusion, cold pressing, partial deoiling	Extrusion: 40–60% moisture, 100–140 °C; Cold pressing: ≤50 °C; Inclusion 5–20%	Improves lipid profile, adds PUFA, modifies texture	Hybrid sausages, burger patties	[40,53]	Risk of erucic acid (e.g., in pumpkin seed protein); oil separation; flavour masking needed

3.2. High-Moisture Extrusion and Coextrusion in Hybrid Meat Systems

High moisture extrusion (HME) is one of the most industrially advanced and scalable technologies for structuring plant proteins into fibrous, meat-like textures, making it an important platform for the production of hybrid meat. Under high moisture conditions (typically 40–70% water content), plant protein isolates, such as soy, pea or faba bean, are subjected to elevated temperatures (120–160 °C) and mechanical shear in a twin screw extruder. This thermal-mechanical treatment denatures and unfolds the protein molecules, causing them to realign through disulfide bonds and hydrophobic interactions into anisotropic structures that resemble cooked muscle fibres [58,59,60,61].

Compared to shear cell technology, which is limited to batch operation, HME offers continuous processing, precise control and higher scalability for industrial applications [62,63]. While it is widely used in the development of plant-based meat analogues, its importance is also increasing in hybrid systems where extrudates serve either as the primary texturising phase or as a scaffold for components of animal-derived origin.

In hybrid formulations, high moisture extrudates are typically mixed with minced meat and fat to produce composite products such as burgers, sausages and meatballs. This combination takes advantage of the fibrous structure, chewiness and water-holding capacity of extrudates, while reducing the meat content by up to 15–50% without compromising attributes important to consumers such as flavour, juiciness and bite [20,27,28,51].

Recent innovations go one step further by directly coextruding meat and plant proteins in a single HME process. For example, Pöri et al. [64] demonstrated the coextrusion of ground beef with native and texturised pea proteins. Their results showed that pre-texturised pea protein improved firmness, fibre formation and umami flavour in the final product, while native pea protein contributed to a softer, more layered matrix but introduced a detectable vegetal flavour. These results show how the pre-treatment and form of the plant protein significantly affect product quality and sensory characteristics in hybrid extruded systems.

Along with traditional plant proteins, novel protein sources are also being explored to diversify the nutritional profile and sustainability of hybrid extrudates. Microalgae, such as Spirulina and Chlorella vulgaris, are of particular interest due to their high protein content, vitamins, essential fatty acids and antioxidant properties. However, their use in extrusion poses both functional and sensory challenges. For example, the addition of up to 50% Spirulina with lupin protein increases antioxidant activity but reduces digestibility and has negative effects on taste and colour, resulting in an earthy-tasting, dark product [65,66]. In contrast, the use of ~10% Chlorella vulgaris pre-treated by high pressure homogenisation shows minimal impact on texture and improves micronutrient density when blended with pea protein [67]. Algal pigments such as astaxanthin from Haematococcus pluvialis are also used in small amounts (0.25–1%) to mimic the red hues of beef and pork and increase visual appeal. However, due to their high lipid content, low hydrophobicity and short peptide chains, most algal proteins exhibit poor structuring during extrusion [60,63].

Insect proteins, particularly from Tenebrio molitor (yellow mealworm), are also being investigated for integration into extruded hybrid matrices. These proteins offer complete amino acid profiles and contain functional lipids, including beneficial polyunsaturated fatty acids, which can contribute to an improved fatty acid profile in hybrid products. However, they are often associated with a strong flavour and darker colour, which can affect consumer acceptance. The success of their incorporation depends on several parameters, including particle size, degree of defatting and blending ratio. Some studies show that defatted insect meal, when co-extruded with soy or pea proteins, improves nutritional quality while maintaining an acceptable texture. Nevertheless, consumer acceptance of insect-based ingredients remains limited in many societies. This is mainly due to food neophobia and cultural perceptions, although a favourable attitude is more often observed when insects are included in processed, less visible forms [68]. Further research is therefore needed to reconcile both taste and sensory expectations and socio-cultural acceptance of insect proteins in meat-like matrices [54,69].

In summary, high moisture extrusion and co-extrusion are versatile platforms for the production of hybrid meat products that combine animal ingredients with texturised plant, algal or insect proteins. These technologies offer a promising opportunity to reduce the meat content without compromising product quality. However, success depends on fine-tuning the pre-treatment of ingredients, extrusion parameters and post-processing strategies. Continued progress in protein functionalisation and consumer-oriented formulation will be critical to move hybrid meat products from proof-of-concept to commercial reality [30,51].

3.3. Integrating Cellular Agriculture and Fermented Biomass into Hybrid Meat Systems

Cellular agriculture and microbial fermentation are emerging technologies with increasing importance for hybrid meat production. These approaches enable the incorporation of non-animal biomass sources such as yeasts, filamentous fungi and cultured animal cells into structured matrices, thereby improving nutritional quality, functional performance and sustainability criteria [16,70,71].

Biomass fermentation, in which microorganisms such as Fusarium venenatum, Rhizopus or Saccharomyces cerevisiae are cultivated, provides protein-rich biomass with good digestibility, balanced amino acid profiles and valuable micronutrients such as B-complex vitamins and zinc [19]. These microbial proteins can be dried, defatted and ground into powder or used as wet biomass with high moisture content, ideal for incorporation into hybrid matrices.

When yeast proteins (YP) at levels up to 30–40% are used in high moisture extrusion together with conventional plant proteins (e.g., soy or pea protein isolates), they have been shown to improve fibre structure formation, whiteness and network cohesion without collapsing during shearing [69]. Rheological studies report that yeast proteins improve the gelation and elasticity of the matrix by promoting intermolecular disulfide bonding and hydrophobic interactions, resulting in improved chewiness, cohesiveness and water-holding capacity [69,72]. Similarly, co-extrusion of fungal biomass (e.g., Pleurotus eryngii, Aspergillus oryzae) with pea protein has resulted in hybrid systems with improved structure and sensory profile [73,74].

Precision fermentation, the use of genetically modified microbes to express specific proteins such as casein, myoglobin or albumin, offers further potential. These bioidentical proteins can be used to mimic the functional and sensory characteristics of proteins of animal origin in hybrid formulations, e.g., gelling, emulsification or enhancement of the umami effect [75]. Although the costs are still too high on a large scale, initial applications indicate the potential to improve the realism of hybrid products and increase consumer acceptance [25,70]. According to some estimates, biomass proteins could be priced at $4 to $6 per kg, approaching competitiveness with conventional meat. These trends indicate that with continued technological advances and economies of scale precision fermentation could become increasingly competitive with conventional meat products in the near future [76].

In parallel, cultivated or cell-grown meat, where animal muscle or fat cells are grown in controlled bioreactors, represents a pioneering way forward for hybrid systems. Rather than attempting to replace meat entirely, many hybrid models propose incorporating 5–30% cultured tissue into structured plant matrices to improve sensory and nutritional properties without the economic and technical challenges of 100% cultivated meat [15,77]. For example, wet-spun pea protein isolate (PPI) scaffolds embedded with cultured chicken muscle cells have been shown to increase essential amino acid content, tenderness and consumer appeal, although the development of off-flavour and cost remain limiting factors [72].

Some patented hybrid systems incorporate cultured fat or muscle either through co-extrusion, post-extrusion injection or lamination techniques and aim to achieve marbled or layered structures that resemble whole cuts of meat [78]. These composite constructs offer new opportunities to replicate muscle fibre orientation, juiciness and flavour delivery in a scalable manner, especially when combined with textured plant-based scaffolds.

However, there are still significant challenges before microbial and cell-based ingredients can be widely utilised in hybrid meat. These include

• Cost and scalability barriers for cell-cultured inputs [16,70];
• Regulatory complexity associated with novel microbial strains and cultured cells in food [71];
• Consistent nutritional and sensory quality, as few studies define thresholds for consumer acceptance of off-flavours, colour shifts or texture inconsistencies in such blends [32].

Nevertheless, these technologies offer a valuable bridge between plant-based innovations and future food systems based on synthetic or cultivated proteins. Their integration into hybrid meat processing, particularly through co-extrusion, scaffold embedding or post-processing incorporation, offers unique opportunities to increase the functionality, realism and sustainability of products without relying entirely on conventional livestock production.

3.4. High-Pressure-Based Treatments in Hybrid Meat Processing

High-pressure processing techniques, including high hydrostatic pressure (HHP) and high-pressure homogenisation (HPH), are increasingly being applied to hybrid meat formulations to improve protein functionality, texture and overall quality [20]. These non-thermal methods are particularly valuable for improving protein–protein interactions between animal and plant components, resulting in more cohesive, flavourful and stable products.

High hydrostatic pressure (HHP) is an isostatic treatment in which food matrices are subjected to pressures of 100 to 800 MPa, usually at ambient or refrigerated temperatures. This process disrupts non-covalent interactions (e.g., hydrogen bonds, electrostatic forces) while preserving covalent structures, thereby unfolding proteins without thermal degradation [79,80]. In hybrid meat systems, HHP has been shown to improve protein solubility, gelation and emulsification capacity while increasing water holding capacity (WHC), reducing cooking losses and preserving nutritional quality [81]. Bernasconi et al. [82] applied HHP at 300 MPa to beef–soy patties and observed improved WHC, a firmer texture and a denser 3D protein network due to improved protein–protein binding. Similarly, Janardhanan et al. [83] demonstrated that the combination of HHP (350–600 MPa) with sous-vide cooking (55–65 °C) reduced cooking losses and improved texture uniformity between hybrid and conventional veal patties. These synergistic effects are particularly valuable in maintaining the sensory appeal of products with reduced meat content. Li et al. [84] found in hybrid protein gels consisting of myofibrillar pork proteins and soy proteins that HHP treatment at 200 MPa improved cooking yield, colour stability, gel firmness and retention of free sulfhydryl groups, all of which are critical parameters for consumer acceptance. However, higher levels of soy protein (≥4%) reduced these benefits, highlighting the importance of optimising the ratio of plant to animal protein and the intensity of pressure to avoid adverse effects on texture and mouthfeel.

Further to HHP, high-pressure homogenisation (HPH) offers a continuous processing method in which protein solutions are forced through a narrow gap at a pressure of 50 to 300 MPa. This creates shear, cavitation and turbulence, resulting in protein unfolding, exposure of reactive groups (e.g., sulfhydryl and hydrophobic sites) and improved solubility and emulsification [85,86]. As a pretreatment, HPH has been shown to be particularly useful in improving the compatibility of plant proteins with muscle-based proteins in hybrid matrices. Zhao et al. [87] reported that HPH-treated quinoa protein improved rheological behaviour, WHC and gel strength when incorporated into low-salt pork gels, which was attributed to the behaviour of 11S globulins. Similarly, Wang et al. [88] demonstrated that chickpea protein treated with HPH and mild heat treatment (80 °C) exhibited better gel structure, whiteness and WHC when mixed with myofibrillar proteins under low phosphate conditions. These effects are significant for the formulation of clean-label hybrid products that do not contain synthetic phosphates or stabilisers.

Taken together, HHP and HPH are powerful tools for customising hybrid meat systems, improving texture, stability and moisture retention while promoting interfacial compatibility between different protein sources. Their role is expected to continue to grow as manufacturers look for scalable, non-thermal strategies to improve the performance and consumer acceptance of the next generation of hybrid meat products.

3.5. Emerging Non-Conventional Technologies in Hybrid Meat Processing

In addition to conventional methods such as extrusion and high-pressure treatment, several new processing technologies have shown promising applications in the production of hybrid meat products. These methods, like ultrasound and pulsed electric fields (PEF) to ohmic heating and shear cell technology, offer refined control over protein structuring, emulsification and sensory enhancement, especially when integrating plant-, fungal- or microbial-based proteins into matrices of animal origin.

Ultrasound processing, particularly in the frequency range of 20–100 kHz, uses acoustic cavitation to generate localised microbubbles and shear forces that break up protein aggregates, increase surface hydrophobicity and improve protein solubility and reactivity [89,90]. These physicochemical changes improve gelling and emulsification behaviour, which are important attributes to ensure compatibility between animal and non-meat proteins in hybrid formats [57,91].

A study by Bertolo et al. [56] demonstrated the use of low-frequency ultrasound (for 1 h at 40 kHz and maximum temperature of 30 °C) on brewer’s spent yeast biomass prior to its incorporation into hybrid beef patties (4% substitution level). The ultrasound treatment improved cooking yield and juiciness, emphasising the potential of sonication to improve the functional attributes of microbial proteins. However, sensory results remained inferior compared to soy-based controls, highlighting the need for additional strategies to mask flavour and optimise texture when non-traditional protein sources such as yeast or fungi are incorporated into meat matrices.

Pulsed electric field (PEF) treatment is another innovation of growing importance for hybrid meat systems that utilise electricity. PEF disrupts cell membranes and improves protein extraction, hydration, emulsification, dispersion and phase stability, especially for plant/fungal substrates [92]. When used as a pretreatment, PEF can improve protein dispersion and reduce phase separation in complex meat-plant mixtures.

Meanwhile, shear cell technology, although still limited to batch operations, offers a low-temperature method for creating laminar fibrous structures that mimic meat texture, particularly from soy or wheat gluten [63].

While these techniques are largely still at the experimental or pilot scale, they provide manufacturers with precision tools to fine-tune the physicochemical and sensory attributes of hybrid meat. Their integration into production pipelines will depend on scalability, energy efficiency and regulatory approval. Nevertheless, their combined potential, especially when used as pre-processing or final treatment steps, could play a crucial role in improving the texture, nutritional quality and consumer acceptance of the next generation of hybrid meat products.

4. Nutritional, Functional, and Sensory Challenges in Hybrid Meat Production and Consumer Acceptance

Hybrid meat products offer a promising opportunity to improve the sustainability, nutritional profile and consumer acceptance of protein-rich foods by blending animal ingredients with plant, algal or microbial alternatives [40]. However, a successful hybrid product requires a nuanced balancing act—integrating different ingredients while maintaining the desired sensory, functional and nutritional properties [53,93].

4.1. Nutritional Synergies and Trade-Offs

Nutritional effects have been evaluated using compositional analyses, in vitro protein digestibility assays, and PDCAAS scoring to assess amino acid availability. Completely plant-based meat analogues are often deficient in essential nutrients such as B vitamins, omega-3 polyunsaturated fatty acids (PUFAs) and essential amino acids such as methionine, lysine, tryptophan and threonine [94]. By combining meat with nutrient-rich plant sources (e.g., cereals, pulses, oilseeds), hybrid products can provide a more complete and digestible protein profile [52,93]. For example, meat complements lysine-rich legumes to provide high-quality protein while reducing the health risks associated with red meat consumption, including cardiovascular disease and diabetes [40].

Numerous empirical studies support this nutritional potential. Textured soy, pumpkin seed and pea proteins have been shown to improve the amino acid profile and protein digestibility when added at levels of 10–50% [48]. For example, hybrid burgers with 10% faba bean concentrate and frankfurters with insect protein have been analysed through simulated gastrointestinal digestion to measure bioaccessibility of essential amino acids. The results showed that they achieved improved digestibility and a protein digestibility corrected amino acid score (PDCAAS) of up to 0.9, compared to 0.7 for entirely plant-based formulations [95,96].

The fat composition varies significantly with the choice of ingredients. Some formulations using insect flour and spent grain have increased fat content [55], while others using hemp seed meal or chia flour lower total fat and cholesterol levels and thus improve the cardiovascular profile [45,97]. At the same time, hybrid products often have favourable lipid profiles as they contain more monounsaturated and polyunsaturated fatty acids, which significantly improve the nutritional value of the end product [98]. However, caution should be taken with ingredients such as pumpkin seed protein, as it can contain erucic acid, which is a problem for vulnerable groups such as children [95].

An important added value of hybrid meat is the inclusion of fibre, which is generally not found in conventional meat [99]. Formulations containing rice bran, pumpkin or brewer’s spent grains achieve more than 3 g of fibre per 100 g, which can be declared as a “source of fibre” according to EU standards and is in line with public health recommendations [55,100]. Another benefit is micronutrient fortification, with insects and plant ingredients contributing iron, zinc and antioxidant phenols, which further improves the functional quality of hybrid products [54].

Nevertheless, the nutritional optimisation of hybrid meat remains an emerging area of research, especially in relation to processing by extrusion. Co-extrusion can degrade sensitive nutrients or alter the interactions between proteins and micronutrients [40]. For this reason, further research is needed to refine processing conditions and confirm long-term health outcomes.

4.2. Functional Properties: Water-Holding and Texture

Functionally, a low to moderate addition of plant proteins (5–25%) often improves water-holding capacity (WHC), oil binding and juiciness by improving protein–water interactions and strengthening the gel matrix [50,84,100]. Chickpea, pea and stabilised rice bran significantly improved WHC in pork and hybrid gels, while up to 50% texturised pea protein reduced fat exudation in emulsified pork systems [49]. However, with a substitution of more than 50%, these functional advantages tend to be reversed. Cooking yield, WHC and stability of the protein network decrease, especially in fermented hybrids, due to the dilution of meat proteins and increased water mobility [93,101,102].

Texture also suffers at higher substitution rates. While small amounts of vegetable protein (<10%) can improve gelling and firmness, higher amounts generally soften the texture. For example, 20–50% pea protein in chicken gels led to matrix breakdown, while soy and rice proteins at 50% reduced hardness and elasticity [48,103]. The deterioration in texture can be partially mitigated by synergistic ingredients such as oat β-glucan, which promote structural cohesion [104].

4.3. Sensory Quality of Hybrid Meat Products

Sensory characteristics, particularly flavour, texture and colour, are key to consumer acceptance of hybrid meat products. The addition of plant, microbial or insect-derived proteins can significantly influence these properties, especially when substitutions exceed 15–30% of the total formulation [45,105,106]. Minor substitutions often improve umami flavour, juiciness and overall palatability by complementing the meat flavour and water-holding properties. However, higher levels can lead to off-flavours (e.g., beany, earthy or musty notes) and blandness, which can have a negative impact on consumer perception [40,104].

Sensory evaluations in the literature typically use trained panels, hedonic consumer testing and descriptive analyses to quantify these effects. For example, Krawczyk et al. [107] evaluated burgers fortified with 5% Alphitobius diaperinus insect protein using consumer sensory panels and found no significant differences in flavour, texture or overall acceptability compared to control samples. Texture is particularly sensitive to the degree of substitution. Low to moderate incorporation (<10%) of plant proteins can improve gelling, firmness and juiciness, while higher levels (20–50%) often soften the matrix and reduce elasticity, especially in emulsified or fermented hybrid products [48,103]. These changes can be partially mitigated by synergistic ingredients such as oat β-glucan or stabilised fibres, which promote the cohesion of the network and maintain the desired bite [104].

Colour stability is another important factor influencing consumer perception. Most hybrid formulations exhibit reduced redness (a*) and increased yellowness (b*) when the degree of substitution increases above 15% [45,48,53,103]. Minimal amounts (0.5–1.5%) of certain proteins, such as faba bean, can maintain an acceptable colour [108]. However, pH shifts and plant pigments can accelerate the formation of metmyoglobin, resulting in browning during storage and cooking [109].

Overall, the sensory quality of hybrid meat products depends on a careful balance between the selection of ingredients, the degree of substitution and the processing methods. Effective masking strategies, flavour enhancers and texture stabilisers are essential to ensure that hybrid products meet consumer expectations. The inclusion of rigorous sensory testing combined with compositional and functional analysis enables researchers and product developers to optimise recipes for palatability and acceptability.

4.4. Consumer Acceptance of Hybrid Meat Products

Consumer acceptance is a decisive factor for the successful market penetration of hybrid meat products. Although these products offer clear environmental and ethical advantages by reducing reliance on conventional livestock farming, they must overcome several perceptual, psychological and cultural barriers to achieve widespread acceptance.

One major challenge is the perceived unnaturalness of hybrid meat. Despite the lower animal content, hybrid products are often perceived as highly processed or artificial, especially those containing cultured cells, microbial biomass or unfamiliar plant proteins. This perception is particularly strong in Western markets, where naturalness is strongly associated with food quality, health and authenticity [45,52]. Consumers may be suspicious of products associated with laboratory-based processes or novel food technologies, even if these innovations improve sustainability and nutritional value [40].

Trust and transparency play an important role in consumer acceptance. Hybrid products often contain several novel ingredients (e.g., mycoproteins, cultured cells, textured legumes) that require clear labelling and effective communication strategies. However, labelling regulations for hybrid meat are still evolving, and terms such as “blended meat”, “hybrid meat” or “enhanced meat” are inconsistently defined in different jurisdictions [45,55]. This regulatory ambiguity contributes to confusion and scepticism among consumers and food producers alike [48]. Transparent disclosure of product composition, origin of ingredients and intended benefits, such as improved environmental properties or less saturated fat, can help to address these concerns [93].

Cultural values, dietary norms and ethical beliefs also influence acceptance. In some populations, reducing meat consumption may conflict with traditional dietary practises or cultural notions of masculinity, strength and status [96,101]. In contrast, hybrid products may be more appealing to flexitarian consumers, i.e., consumers who are motivated by health or environmental concerns but are not fully committed to vegetarianism or veganism [94,95]. These consumers may appreciate the compromise that hybrid meat represents: fewer animal ingredients without sacrificing flavour, texture or familiarity [53].

Flavour and texture remain key factors. Regardless of sustainability or ethical considerations, hybrid products must fulfil sensory expectations. Consumers are unlikely to repurchase products that do not replicate the juiciness, mouthfeel or umami characteristics of conventional meat [38,54]. Hybrid formulations that focus on sensory quality, e.g., through advanced extrusion, emulsification or flavour masking, are more likely to be successful in competitive food markets [97]. As Grasso et al. [45] emphasise, taste is still the most important driver of food choice, and even sustainability-conscious consumers are not willing to make significant compromises in the eating experience.

Education and outreach will be critical to long-term acceptance. Public understanding of alternative proteins and their environmental impact remains limited [52,100]. Educational initiatives that place hybrid meat in the context of global sustainability challenges such as land degradation, greenhouse gas emissions and resource inefficiency can help to change consumer attitudes [33,55]. Marketing strategies should emphasise understandable benefits (e.g., “lower cholesterol”, “made from real vegetables”, “less impact on the planet”) rather than technical innovations that may deter risk-averse buyers [96].

Finally, early adopters and younger demographics can serve as important entry points. Millennials and Generation Z consumers have shown a greater openness to plant-based and alternative proteins, especially when positioned as innovative, ethical or climate-friendly [40,53]. Targeting these groups via digital platforms, influencer campaigns and partnerships with food services can accelerate market growth and normalise hybrid products in broader consumer segments.

5. Conclusions and Future Direction

Hybrid meat products, which combine animal proteins with plant, microbial, algal or cultured ingredients, offer a pragmatic solution to reduce the environmental and health impact of conventional meat while retaining familiar sensory properties. At moderate substitution rates (20–50%), these products can maintain or even improve the texture, juiciness and nutritional profile compared to meat and fully plant-based analogues. Technological advances in extrusion, co-processing and protein structuring have enabled increasingly sophisticated formulations. Nevertheless, achieving a convincing meat-like texture, flavour and colour at higher substitution rates remains a major challenge. Consumer acceptance is increasing, especially among flexitarians, but is still driven by sensory quality, familiarity and perceived health benefits. Legal uncertainties, production costs and scalability continue to limit widespread acceptance.

Future research should focus on the optimisation of hybrid formulations with an emphasis on achieving adequate nutritional value, sensory quality and cost-efficient processability. In parallel, comprehensive life cycle analyses are required to substantiate the claim of sustainability. This includes analyses of land use, water consumption, energy requirements, greenhouse gas emissions and waste generation. Finally, transparent communication requires more than general messaging: it should include clear labelling, open disclosure of ingredients and processing technologies, and evidence-based communication of nutritional and environmental benefits to build consumer confidence. Interdisciplinary efforts in these areas are essential for hybrid meat to realise its potential as a scalable, nutritionally adequate and environmentally sustainable component of future food systems.