Introduction
According to the OECD and FAO (2021), it is anticipated that the consumption of meat proteins worldwide will experience a 14% rise over the next decade, mostly driven by escalating income levels and population expansion. This projection is in comparison to the average consumption levels observed between 2018 and 2020. The escalating demand is intricately linked to a range of issues, encompassing public health and environmental challenges, as well as concerns over animal care and ethical considerations. It is anticipated that the rise in global meat production would lead to a significant increase in greenhouse gas emissions (FAO, 2014), as well as water pollution, diminished access to fresh water, and adverse alterations in biodiversity, all of which pose a direct threat stemming from the expanding livestock sector (Steinfeld et al., 2006). According to Sarlio (2018), the utilization of calories by animals for maintenance and non-edible tissue creation is estimated to be approximately 97%, which is widely regarded as inefficient. The consumption of meat especially red meat in excessive amounts has been found to pose health hazards for individuals (Abu-Ghazaleh et al., 2021). Nevertheless, cultured meat (CM) from live animal cells may fit the consumer demand for growing real meat consumption (Ismail et al., 2020).
CM is produced from live animal cell cultures and is considered an alternative to real meat (Post, 2014). CM approach acquired a larger concentration globally in the research arena, media, investors, specific groups of consumers, and animal welfare organizations (Goodwin and Shoulders, 2013; Schneider, 2013; Stephens et al., 2018; Verbeke et al., 2015). A great number of efforts are ongoing to produce CM to mimic real meat from beef, poultry, pork, and seafood by researchers. The so-called hybrid CM (HCM) is a hybridization of animal cells and possible ingredients from plants, bacteria, and algae including various types of binders to mimic the real meat taste and texture of real meat (Lee et al., 2023). Hybrid meat products represent a novel category of goods wherein a portion of the meat content, often around 20%, is substituted with alternative protein sources, including plant-based alternatives (Baune et al., 2023). According to existing research, these products have the potential to function as a viable option for a particular demographic seeking to reduce their meat consumption, therefore aiding in the transition towards a diet that is both healthier and more environmentally sustainable.
CM is expected to be safer in terms of public health (Willett et al., 2019) and a way out toward a sustainable way to produce food with high-quality protein and theorized to be able to produce 1 billion beef burgers from a single cow biopsy (Kumar, 2021). The first-ever regulatory approval for CM production was for “Eat Just” in 2020 in Singapore (GFI, 2020). Upside Food and GOOD Meat got final approval from the FDA and USDA for marketing and selling cultured chicken meat products in 2023 (GFI, 2023). CM still possesses major challenges in terms of high production cost, product quality, and consumer embracing (GFI, 2023). Numerous developments need to be addressed to make CM mimic real meat e.g., myoglobin production, marbling of the meat, culture media optimization, sustainable production techniques, muscle bundle formation to mimic different meat cuts, major sensory attributes, nutritional values, and scaffolding technology (Levi et al., 2022), etc.
Several commercial manufacturers ventured into plant-based meat (PBM) market and few stand out as pacesetters e.g., Beyond Meat, Impossible Foods, Eat Just, Memphis Meats, Aleph Farms, Mosa Meat, Cultured Decadence, and BlueNalu (GFI, 2023). These companies advance toward sustainability in manufacturing HCM, including PBM, through production capacity, product quality, legislation, and research and development based on consumer demand. In this regard, this paper reviews the opportunity of HCM or meat alternatives and the advanced challenges related to the structural and sensory characteristics to focus the consumer sustainability.
Commercial Prospect of Cultured Meat
According to the Good Food Institute, the Overall value of CM in 2022 is estimated at USD 0.3 Billion and is expected to grow to USD 20 Billion in 2023 with a growth rate of 143% (GFI, 2023). Health safety, environmental pollution, and vegan movement issues trigger a driving force to alternative meat solutions both by the industry and the consumers. Table 1 indicates an immense opportunity for this sector in the future (GFI, 2023). There are 28 companies working on meat-based products, out of which sixteen are involved in the production of CM or plant-based analogs and scaffolding. There is one research-based company working on serum-free culture media and the other one on techniques and ingredients to boost the texture of meat alternatives. Nine companies are in the development phase for the production of CM and meat alternatives and one is involved in the development of a cell line for CM.
Data modified from GFI (2023).
In recent days the intensified interest of consumers in PBM products and CM is an outcome of continuous product development and marketing efforts. The conception of any new invention always has some drawbacks and, in this case, there are challenges from consumers and technological barriers (Sanchez-Sabate and Sabaté, 2019) especially on meat color, texture, taste, etc. as real meat and emphasized by researchers for future improvements (Bakhsh et al., 2021, Bakhsh et al., 2022; Weinrich, 2019). By embracing and developing various sorts of reorganizational technology, such as 3D scaffolding, PBM and CM may be able to deliver safer and more environmentally friendly state products. So far plant and animal-based CM found to be safe and could be ideal alternatives to address the growing need for animal protein with the growing global population (Zhang et al., 2022). In the parts that follow, an explanation will be given of the technological characteristics that might offer solutions to the problems in Human Capital Management. This is done with the intention of generating the need for additional research.
Sensory Characteristics of Hybrid Cultured Meat
Processing of different functional ingredients turns into a brand-new appearance with consistent nutritional characteristics known as ‘Restructured food’ (Polášek et al., 2021). Various food additives are included to develop compounded structured food (Carpentieri et al., 2022). Structured meat is a type of reconstituted food that is attaining admiration from consumers as a substitute for orthodox meat products. HCM is a kind of structured food that reassembles animal-based CM with PBM to create a new texture and appearance that mimics real meat. Structured meat like HCM is considered to be safe, healthy to consume, and capable of solving animal welfare issues. However, in order to gain a preference that can meet consumer expectations, HCMs containing PBM will have to have sensory characteristics similar to those of natural meat (Bakhsh et al., 2022). The texture, color, taste, etc. would be the major criteria in marketing this kind of cell-based CM in the future (Joo et al., 2022). In addition to these sensory characteristics, consumers will also be increasingly interested in nutrition. The development processes employed in controlled atmosphere packaging are intricately linked to the structural composition of muscle tissue, as the shape of muscles is directly associated with the nutritional and sensory attributes of meat. Satellite cells are predominantly obtained from the skeletal muscles of several animal species, including cattle, chicken, swine, lamb, and fish, in contemporary methodologies. The fibrous texture commonly observed in red meat, such as beef, can be attributed to the intricate hierarchical tissue organization. The muscle fiber serves as the fundamental functional component, encompassed by connective tissue, intramuscular fat, vascular, and nerve tissues. According to Listrat et al. (2016), the key factors that influence muscle texture and quality characteristics are muscle fibers, fat, and connective tissue. HCM products have the advantage of being able to produce customized nutritional products for consumer needs. In this regard, research on the development of HCM products focused on the nutritional and structural development of meat that meets consumer needs will present immense opportunities for CM market in the near future.
To effectively design HCM products that align with customer demands, it is imperative to do research on plant proteins that constitute a substantial proportion of HCM and/or PBMs produced using these proteins. While the PBM sector is experiencing growth in the market, it is important to consider that negative sensory feedback from customers has the potential to restrict its market expansion. The texture and sensory attributes of PBM are not on par with those of actual meat, as the fibrous structure of meat plays a vital role in this regard (Lee et al., 2023). The inclusion of hydrocolloids is known for their potential to improve the textural properties of PBM. Hydrocolloids could be precious for the development of PBM to improve texture and sensory characteristics. The myofibrillar protein, which primarily comprises myosin and actin, is crucial in the development of the desired texture and water-holding capacity of comminuted beef products. High Acyl gellan gum was shown to produce large fibers when PBM containing soy protein isolate (SPI; Taghian Dinani et al., 2023). Positive feedback was revealed from the addition of wheat gluten on the texture, binding properties, moisture retention, and sensory attributes in PBM (Chiang et al., 2021). But as an allergen wheat gluten is not accepted by consumers with enteric problems (Theethira and Dennis, 2015).
Meanwhile, edible cell microcarriers can be directly added to the final HCM product, which may reduce the cost and yield losses (Nienow et al., 2014). Edible cell carriers like Chitosan-collagen (90:10) were successfully produced to culture from different primary livestock animal cells and have considerable potential for the development of CM products when incorporated these carriers can contribute to the CM sensorial and nutritional values (Zernov et al., 2022).
Plant Proteins Used in Manufacture of Hybrid Cultured Meat and/or Plant-Based Meat
The obstacles encountered in the development of PBM substitutes revolves around the replication of tactile characteristics inherent in meat-based products, such as mouthfeel, chewiness, cohesiveness, and springiness. Nevertheless, the development of desired characteristics in food products relies on the interplay between the selected protein(s) and/or non-protein components, as well as the utilization of sophisticated and innovative techniques, owing to the inherent disparities in the structural chemistry of plant and meat proteins (Mattice and Marangoni, 2020).Various plant proteins, including those found in cereals, legumes, pulses, and leaves, can be used to make plant meat alternatives (Lee et al., 2023). Commonly wheat, corn, rice, barley, sorghum, and amaranth grain are sources of cereal proteins. Moreover soybeans, rapeseed/canola, sunflower seeds, sesame, flaxseeds, and linseeds are sources of oil-seed proteins (Kyriakopoulou et al., 2019).
Soy protein, specifically in the forms of SPI, soy protein concentrate (SPC), and soy flour, serves as the primary plant-based protein utilized in the production of PBM and/or HCM. Soy proteins have a wide range of functional qualities, including hydrophilicity, lipophilicity, emulsifying capabilities, and the capacity to create gel structures. In order to produce artificial meat substitutes, SPC and soy protein are frequently employed and they play an important role in reducing product cost and making it competitive in the market (Bakhsh et al., 2022).
The extraction process demonstrates that SPI possesses a comparative advantage over SPC in terms of protein content. Various approaches were employed for protein extraction in the case of each product. An alcohol extraction is used to collect SPC where it retains about 70% of its protein content (Lee et al., 2023). On the other hand, protein retention is 90% in the case of SPI. An alkaline extraction and leached at an acidic pH assisted in having 90% of its protein content. SPI is well accepted in the industry and research arena for the production of meat analogues due to its brighter color and a drearier flavor than other soy-sourced ingredients (Kyriakopoulou et al., 2019). The end products of SPI possess a meat-like texture after hydration and are much more economical than the other plant protein sources (Sun et al., 2021). The physiological and nutritional characteristics of soy protein have been found to surpass those of actual meat. Meat mimics created employing soy-derived proteins exhibit a larger protein content compared to authentic meat, and furthermore, they possess elevated nutritional properties. Moreover, it has been demonstrated that the fat and cholesterol levels in plant-based alternatives are comparatively lower when compared to those found in traditional meat sources (Cavallini et al., 2006).
Wheat gluten, which forms thin proteins on elongations and may be swiftly converted into a fibrous protein, is another often used grain protein. Wheat gluten used as a scaffolding material in the development of meat analogues in its 3D network form. Wheat protein is known for its, which helps provide the most commonly encountered form of consistent meat analogues. Additionally, to create meat extenders, wheat gluten can be combined with soy flour or SPI (Asgar et al., 2010). The allergens in wheat gluten should be taken into account while using in the production of meat analougues, as these could be problematic for children (regular and with special need) and sensitive consumers (Keet et al., 2009; Martínez-Villaluenga et al., 2008). Nevertheless, due to its water insolubility, wheat gluten cannot be used extensively in the food processing industry (Asgar et al., 2010).
Legumes are widely recognized for their high-quality and abundant protein content. Legume protein sources encompass a variety of plant-based foods, including beans, chickpeas, lentils, lupines, and peas. Legume-based proteins have a notably abundant amino acid composition in comparison to alternative plant sources. They are rich in lysine and threonine, but in comparison to cereal grain-based proteins methionine, cysteine, and tryptophan are shallow (Kurek et al., 2022). Emulsification, gelation, and foam stability are three functional characteristics exhibited by legume proteins, which enhance the efficacy of using plant protein products as food additives. Emulsification, gel formation, and foam stabilization are three functional traits of legume proteins that improve the utilization of plant protein products as food additives (Ettoumi et al., 2016). High-moisture extrusion has been used to create materials with a fibrous morphology from pea protein isolate and wheat gluten (Schreuders et al., 2019). SPI, SPC, and other plant proteins derived from soybeans are often used ingredients in the production of PBM. The identification and incorporation of alternative sources of plant-based proteins is of utmost importance. Furthermore, apart from using single ingredients, the combined effect of one or more ingredients is necessary to produce significant combinations suitable for commercial production, economic feasibility, and overall sustainability (Bakhsh et al., 2022). The primary issues associated with plant-based proteins pertain to their eating quality, specifically their capacity to effectively replicate the appearance, texture, flavor, taste, and nutritional composition of actual meat products. Furthermore, it is imperative that the product possesses the capacity to be manipulated in a manner akin to uncooked meat, and then prepared in a manner resembling meat cooking techniques, resulting in a final product that elicits a sensory encounter like to the consumption of meat. Despite advancements in the enhancement of texture and flavor in PBM alternatives, there remain obstacles in delivering a satisfactory sensory encounter and enhancing the nutritional value of such products.
Improvement of Sensory Characteristics
In natural meat, the presence of myoglobin is what gives it its distinctive red hue; in CM, on the other hand, myoglobin is not present, which results in a more pale appearance. Myoglobin expression is extinguished at ambient oxygen conditions (Gholobova et al., 2018; Lee et al., 2022; Thorrez et al., 2006). A number of initiatives guided way out to increase the myoglobin content in CM or PBM (Fraeye et al., 2020), summarized in Table 2.
Present observations | Future research needs |
---|---|
Low oxygen ambience may increase myoglobin expression during culturing muscle fibers (Post and Hocquette, 2017; Simsa et al., 2019). | Need further evaluation to assess the impact of low oxygen conditions on cultured meat (Kanatous et al., 2009; Schlater et al., 2014). |
Hypoxic conditions resulted better efficiency with increased glucose uptake and lactic acid production and lipids or acetic acid media showed stimulation of myoglobin expression (Moritz et al., 2015). | Need further evaluation to assess the impact of low oxygen conditions on cultured meat (Kanatous et al., 2009; Schlater et al., 2014). Possible acidification may damage the cells (Kadim et al., 2015). |
Sufficient iron is mandatory in the cell for myoglobin synthesis and color development (Rubio et al., 2019). | Uptake is transferrin-dependent (Kadim et al., 2015). |
Myoglobin content in cultured meat may be improved by direct inclusion of myoglobin, recently addition of metmyoglobin (the oxidized form of myoglobin) increased cell proliferation and the content of myoglobin in cells (Simsa et al., 2019). | Bioavailability of iron and inclusion limit into myoglobin needs to be studied (Simsa et al., 2019). Still, the color of cultured beef meat is pale than real beef after adding metmyoglobin. |
The possibilities of artificial color or plant-derived colors are under observation but only for processed meat products. Soy leghemoglobin was able to give the color and taste of a real beef burger (Watson, 2019). | As red meat is associated with health concerns, it is wise to develop alternative colorants for cultured meat (Gamage et al., 2018). |
Consumer preference starts with the optical inspection of a product and has immense importance in meeting their expectation, especially for novel foods (Moore et al., 2021; Post and Hocquette, 2017; Post et al., 2020). The presence of marbling patterns in meat is known to increase consumer acceptance when purchasing (Lo Surdo et al., 2013). This can be achieved by mimicking the marbling patterns found in traditional meat. By incorporating fat cells alongside muscle cells, cell-based meats can develop marbling patterns that enhance their visual appeal. Additionally, advanced 3D printing technologies can be utilized to create intricate structures that resemble marbling patterns, further improving the visual appearance of cell-based meats (Ong et al., 2021). To create a well-integrated structured CM that replicates the texture of conventional meat, the engineered adipose tissue was integrated within engineered bovine muscle tissue using a gentle stitching process that allowed the co-culture of the integrated construct while preserving the delicate mature adipocytes (Zagury et al., 2022). Marbling and three-dimensional type superior structure in CM yet not established in current culture techniques (Datar and Betti, 2010; Jurie et al., 2007).
The process of CM creation necessitates the utilization of satellite cells derived from live animal muscle, which are subsequently deposited onto a biomaterial substrate commonly referred to as a scaffold, microcarrier, or film. This foundation stimulates the proliferation of satellite cells in order to increase their population size. Following this, the progression of muscle fibers and adipose tissue formation persists through the process of differentiation, with the ultimate objective being the replication of the authentic structure of meat (Ostrovidov et al., 2014).
In the field of CM, it is of utmost importance to ensure the appropriate arrangement of fiber bundles in order to accurately replicate the structural characteristics observed in conventional meat. The attainment of well-organized meat can be accomplished through the utilization of scaffolds, which provide cells with an extracellular matrix-like framework for the purposes of support, differentiation, and proliferation. Different strategies are in use for scaffolding e.g., microcarriers, porous scaffolds, fiber scaffolds, hydrogels, 3D printing, scaffold-free approaches, etc., and synthetic polymers, self-assembling peptides, ECM molecules, plant & fungus derives materials are commonly used scaffolding materials (Bomkamp et al., 2022). There are four key aspects that need to be taken into account for tissue engineering (TE), of which the mechanisms are similar to scaffolds being used for CM production. Biocompatibility, biodegradability, the architecture of the scaffold, and the technology used to manufacture the scaffold are the four important areas that need to be addressed during the production of CM through TE (Seah et al., 2022). Micro carriers found to significantly increase the efficiency of cell proliferation and differentiation and it’s achieved by expanding the surface area and serving anchorage-dependent cells a link (de Jong, 2023). The properties of scaffolding such as microcarriers have often been inspired by the field of TE, which needs to be adapted for CM (Singh et al., 2023).
Scaffolds that are frequently employed has the ability to be utilized in the production of human cardiac muscle because to their edible nature or their rapid biodegradation during the phases of differentiation and maturation. The utilization and advancement of edible scaffolds have the potential to decrease the expenses associated with the production process of HCM, as these scaffolds can be commercialized as a product. According to Ng and Kurisawa (2021), if edible scaffolds are to be retained in the final product, it is imperative that they are both harmless and safe for consumption, without altering the flavor or texture. Further investigation is necessary to explore sustainable, efficient, viable, and ultimately consumable polymers for implementation in the CM sector.
Conclusion
The allocation of investments and the level of interest exhibited by investors in this particular industry may serve as a promising indicator for the prospective expansion of CM and meat alternatives in the future. Consumer interest in meat alternatives, such as CM, may experience a decline unless their prices become comparable to that of actual meat. The primary research and industrialization objective should revolve around replicating the color and texture of authentic meat in order to align with consumer preferences and enhance pleasure. The consideration of production costs is a crucial aspect to be taken into account throughout the development of a product such as lab-grown meat, specifically in the context of HCM manufacturing. The development of non-animal-based colorants, additives, and colloids that are more efficient and cost-effective, along with the implementation of sustainable scaffolding techniques for constructing 3D scaffolds and ingestible scaffolding material, holds the potential to revolutionize the meat industry. This vision is shared by researchers and industrialists who aspire to establish a sustainable future for the industry. The application of the electrospinning technology has the potential to be utilized in the development of cost-effective 3D scaffolds, hence potentially leading to a reduction in the overall production cost of CM. Furthermore, there exist potential opportunities for enhanced alignment of muscle fibers in a three-dimensional scaffold, thereby replicating the authentic structure of meat.