Abstract
Global demand for food is expected to nearly double by 2050. Alternative proteins (AP) have been proposed as a sustainable solution to provide food security as natural resources become more depleted. However, the growth and consumer intake of AP remains limited. This review aims to better understand the challenges and environmental impacts of four main AP categories: plant-based, insect-based, microbe-derived, and cultured meat and seafood. The environmental benefits of plant-based and insect-based proteins have been documented but the impacts of microbe-derived proteins and cultured meat have not been fully assessed. The development of alternative products with nutritional and sensory profiles similar to their conventional counterparts remains highly challenging. Furthermore, incomplete safety assessments and a lack of clear regulatory guidelines confuse the food industry and hamper progress. Much still needs to be done to fully support AP utilization within the context of supporting the drive to make the global food system sustainable.
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Introduction
With the global population expected to reach 9.7 billion by 20501, the world is now facing the challenge of producing sufficient and nutritious food to feed all at a time of increased competition and scarcity of land, water, and energy resources2. Among the three major macronutrients, the predicted demand for proteins has sparked a range of concerns, most notably whether its supply can be met by harvesting from traditional sources of protein alone, such as livestock. In addition, the livestock supply chain has been considered a significant contributor of greenhouse gases (GHG), accounting for approximately 14.5% of total GHG emissions; there is an association between livestock GHG emission and climate change3. With increasing demand for both human and animal feed, the conversion of forests, wetlands, and natural grasslands into agricultural lands is a threat to our environment and climate4. Such practices will lead to a marked loss of biodiversity4. Moreover, the rise in antibiotic resistance has been linked to the overuse and misuse of antibiotics in intensive animal production4,5.
In response to the global demands and concerns around future protein needs, the concept of alternative proteins (APs) was initiated and rapidly gained considerable attention4. This concept is not new as APs were predominantly and traditionally consumed by vegans and vegetarians, with soy, legumes, and wheat protein acting as the main ingredients6. Insects are also included in the diet as nutrient sources in some regions such as Africa and Asia but not on a regular basis7,8. However, there has recently been an upsurge of innovation backed by huge investments in the development of AP products with visual appearance and texture that are similar to animal-based products4. Protein sources have been diversified from a primarily livestock-based system to include four additional categories: plant-based, insect-based, microbe-derived, and cultured meat and seafood (Fig. 1). Each of these protein sources is at a different stage in its development. Plant-based proteins are the most widely accepted, as reflected by a markedly growing market segment9. It is predicted that plant-based proteins will be the first AP that achieves price parity with their conventional counterparts, followed by microbe-derived protein and cultured meat10. The AP market has been estimated to grow exponentially from USD 15.3 billion in 2023 to USD 26.5 billion by 2030 (Fig. 1)11.
a Currently available AP, b market volume, c key benefits, and d projected market growth of alternative proteins. MP refers to microbe-derived protein. GHG refers to greenhouse gases. AMR refers to antimicrobial resistance. CAGR refers to the compounded annual growth rate indicating a rate of return for an investment on the products. Pictures of each protein are designed by Freepik. https://www.freepik.com/free-photo/high-angle-beans-arrangement-concept_9861472.html; https://www.freepik.com/free-photo/emerald-green-bubbles-acrylic-painting_5682750.htm; https://www.freepik.com/free-photo/close-view-yummy-exotic-dish_5007103.htm. https://www.freepik.com/free-photo/top-view-fresh-meat-slices-raw-meat-round-wooden-desk-dark-food-freshness-animal-cow-meal-food-kitchen_17232551.htm.
Although APs have gained substantial interest amongst the scientific community as well as the food industry, they are still considered a small sector with a 42% decline in investment in 202212; APs are not widely appealing to many consumers. This is mainly due to their sensory characteristics, relatively high prices, consumer unfamiliarity, and unassured health consequences9,13,14,15.
Today, the AP industry is facing significant challenges in terms of cost-effective scale-up production16. Compared to animal-based proteins, most of APs must be extracted, isolated, or separated from their starting materials (Fig. 2). Therefore, APs inherently exhibit different functional properties that play important roles in food processing technologies, so-called techno-functional properties. Therefore, it is challenging to formulate food products with similar properties and quality as seen in conventional products. In addition, the long-term health consequences of a dietary shift towards APs remain to be fully elucidated. A majority of consumers associate insect-based proteins and cultured meat with not being ‘natural’, feelings of disgust, and often refuse to even try the products13. Indeed, consumers appear to be more open to those alternatives if the products are proven to have global and societal benefits13. Regardless, the true environmental impacts of APs must be fully assessed and clearly communicated to consumers. Most importantly, there are still no international guidelines and standards for APs17, and the regulatory status varies among countries. For instance, during manuscript preparation, Singapore and the USA are the only two countries that recently approved the sale of cultured meat18, while other countries do not have any similar standard guidelines. There is little doubt that the combination of all these issues has markedly slowed the growth and utilization of APs.
a plant-based protein, b insect-based protein, c microbe-derived proteins, and d cultured meat and seafood.
The objective of this review is to systematically analyze the peer-reviewed scientific literature on the four categories of APs in terms of environmental impacts, challenges to utilization, future trends, and opportunities. The primary selection criteria include the published years between 2010 and 2023, the type of documents (i.e., original research and review article), and the search keywords (i.e., plant-based protein, plant-based meat analog, meat analog, insect protein, microbial protein, single-cell proteins, culture meat, lab-grown meat, cultivated meat and seafood). The reports with any risks of misleading results due to study design or conduct were excluded. Other materials, including news, regulations, standards, guidelines, and statistical information were further looked up for to complement the main context. Obtaining balanced and improved insights is needed for scientists, the food industry, and policymakers to support the future development of APs to better support global food security.
Environmental impacts of APs
The potential environmental benefits of APs have been widely cited to promote foods based on these commodities7,8,9,19,20,21. Most studies focused on comparing the impacts between the production of livestock and APs such as plant farming, insect rearing, and microbial biomass fermentation. However, full life cycle assessment studies on the entire AP supply chain are very limited22,23.
The cultivation of plants, insects, and microorganisms generates less environmental burden than livestock farming. Growing high-protein plant materials (i.e., nuts, peas, and other pulses) emits 40 to almost 100 times less GHG (kg CO2-eq/100 g protein) and occupies 20–50 times less land space (m2/100 g protein) than lamb and bovine rearing (Table 1). Compared to pork, poultry, and farmed fish, plant cultivation produces 10–15 times less GHG but requires a similar land space. Similar benefits have also been observed for insects. For instance, it has been shown that mealworm (Tenebrio molitor) farming expels 75 times less GHG emission, occupies 102 times less land use, and produces 35 times less water footprint than those for ruminants20 (Table 1). In addition, insect farming generates markedly less methane and ammonia21, due to a greater efficiency for feed conversion21 than conventional livestock production. As for microbe-derived proteins, studies have shown up to 62 times lower GHG with almost 2000 times less land than animal-based proteins (Table 1). It is very interesting and indeed relevant that comparing the production of plant-based proteins with microbe-derived proteins, the latter consumes less land, by 3–80 times per 100 g protein, depending on the type of plants and the final products generated24. Another important point is that various forms of agro-industrial waste, such as pea-processing byproducts25, brewer-spent grains, and grape bagasse26, can be used as feed for the cultivation of filamentous fungi.
The available literature indicates a marked decline in GHG emissions and land use for producing plant-based milk alternatives than cow’s milk (Table 1). Data has also shown that manufacturing meat analogs either from plant- or microbe-derived proteins emitted GHG at a greater quantity than growing the plants alone. Yet, it is considerably lower than that of animal-based products (Table 1). Production of alternative products from both plant and microbe-derived proteins requires less space than livestock-based products (Table 1). Data on the water footprints of these products require further investigation. It is worth noting that the current technologies for plant and insect-based protein extraction using alkaline solvent consume a large amount of energy and result in excess wastewater that requires further treatment. Technology-assisted extraction, product formulation, and the structuring of meat analogs are actively being developed; an assessment of the environmental impacts of APs must be regularly updated and the data made visible to all stakeholders.
The true environmental impacts of cultured meat and seafood have not been fully assessed yet as their production systems are still in their early phase. Only a few products (i.e., cultured chicken) have been commercialized in Singapore and the USA27. The process of culturing meat from cell culture and other agricultural products from cell cultures is known as cellular agriculture28. In terms of cultured meat, stem cells are grown in a media containing all the required nutrients (e.g., hormones, growth factors, and fetal bovine serum) under controlled conditions to enable cell division and proliferation in a conventional manner, such as the one seen in the vaccine industry. A recent study indicates that the carbon footprint and energy consumption of cultured meat depend greatly on the efficiency of the medium usage27,29,30. In the case of low efficiency, the carbon footprint and energy consumption per kg of obtained products could be as high as 22.6 kg CO2-eq (8.7 kg CO2-eq/100 g protein, assuming equal protein content with beef) and 264 MJ respectively. If the culture medium was utilized at high efficiency, the carbon footprint and energy consumption could be theoretically reduced by 90% and 50% respectively28. However, this is far from being achievable given the current technology. Although the process of culturing meat requires less land30,31,32, the need for high concentrations of nutrients (e.g., glucose and amino acids) to culture the cells and tissues is expected to leave a negative impact on its environmental footprint27.
Challenges in the application of APs in the food industry
Technological challenges
Many of the AP products fail to fully mimic the organoleptic experience of their conventional counterparts and thus have received limited consumer acceptance33. Such technological challenges are based mainly upon molecular and physicochemical differences that cause substantial deviations in the techno-functional properties between alternative and animal proteins34.
Most plant proteins are globular and stored as preserved nutrients in storage organs (e.g., seeds and tubes)35, hence why protein extraction is required (Fig. 2a). In addition, plant proteins can form heat-induced gels and also exhibit emulsifying properties; however, a sufficiently large concentration is needed to achieve the same gel strength as that of animal-based proteins36. Soy and pea proteins show comparable solubility and emulsifying properties to egg proteins but a much higher temperature and longer heating time is required to obtain a similar texture to those of cooked eggs34. Although insect-based proteins can form heat-induced gels, they usually show poor foaming ability37,38. Insect proteins can be used in the form of whole insect flour or solvent-extracted insect-based proteins but the techno-functional properties of insect protein ingredients will be influenced by non-protein components (e.g., chitin)36. The structure and functional properties of insect proteins are very diverse, depending on the organ (e.g., muscular system vs cuticles), insect species, and stage of life39. Exposure to chemical solvents, mechanical milling, and thermal treatments during pretreatments and protein extraction (Fig. 2a, b) can induce partial denaturation and aggregation of plant- and insect-based proteins, altering techno-functional properties34,40.
The development of whole-muscle meat analogs is the most challenging aspect for plant- and insect-based proteins. Today, high-temperature extrusion is commonly used for producing commercial meat analogs. Extrusion technique can be classified based on moisture content into low-moisture (10–40%) and high-moisture (60–70%) extrusions. Low-moisture extrusion is a common process used for manufacturing texturized vegetable proteins. Meat analogs acquired from texturized vegetable proteins visually and texturally differ from animal meat41. On the contrary, high-moisture extrusion, by producing anisotropic structures resembling fibrous characteristics of whole-muscle meat42, is widely used in the production of commercial plant-based meat analogs and has also been shown to experimentally structure similar products from the insect-based43. Fat can be co-extruded to obtain fat marbling on meat cuts. However, the aggregates do not completely resemble the architecture of a muscle fiber, leading to different properties compared to conventional meat. Meat analogs are often perceived as lacking juiciness44, with low cohesiveness and a fibrous texture45. Considerable amounts of processing aids, e.g., structure-forming, flavoring, and coloring agents, are added to the products to compensate for the inferior techno-functional properties of plant- and insect-based proteins46. However, this practice does not align well with the growing trend of “clean label”. In addition, high-moisture extrusion is considered energy-intensive42. Process control of extrusion is challenging due to the complex interplay of process parameters and material properties47. Other developing technologies for whole-muscle structure formation include shear cell technology, electrospinning, 3D printing, and wet spinning47. Of these, shear cell technology, through its use of intensive shear and elevated temperatures to structure the proteins, has shown good potential for up-scaling operations48. However, these technologies remain a subject for more intensive examination. For other alternative products (e.g., milk, cream, butter yogurt, and eggs), the proteins are formulated as a single protein or protein blends with the inclusion of processing aids to produce gelling, emulsification, and foaming to increase stability during homogenization, thermal processes, and cold storage49,50,51.
Similar to plant- and insect-based proteins, the techno-functional properties of microbe-derived proteins are diverse, depending on the microbial species, production system, and non-protein components used52. Microbe-derived proteins are generally obtained from microbial biomass of bacteria, yeasts, fungi, and microalgae grown in bioreactors or other controlled environments (Fig. 2c)53,54. The biomass produced by the fermentation process is then harvested using centrifugation and may be subjected to protein extraction or other processing techniques. However, dry biomass exhibits inferior oil binding and foaming properties compared to the extracted microbe-derived proteins due to its high content of insoluble fiber55. In addition, thermal treatment, aimed at reducing RNA content in microbial cells, may induce partial denaturation of the proteins, thus altering its techno-functional properties52. Nonetheless, constructing meat analogs from filamentous fungi appears to be less challenging than plant- and insect-based proteins as the fiber-oriented structure, obtained after biomass centrifugation, already visually resembles ground meat42. The biomass can be dried and further formulated as chunks, incorporated into ground meat and comminuted products, or formed into whole-muscle meat using binding agents42. In terms of mycoproteins, while some commercial products have been marketed for several years, the available technology still greatly impacts the environment56.
Another challenge of plant-based, insect-based, and microbe-derived proteins is mimicking the taste, odor, and flavor of animal-based products. Based on different biomolecules present, APs inherently have their own taste and flavor profiles that are very distinct from animal-based products. Plant-based proteins are often associated with beany and grassy flavors, a bitter and chalky taste, astringency, and a strong aftertaste44. The off-flavors in plants vary among plant cultivars and the amount of proteins used and may arise during protein extraction, food processing, and during storage57. For insects, the flavor profile is diverse, ranging from nutty, buttery, milky, earthy, to fishy39,58, depending on the species, stage of life, body part, and source of feed39. Some studies have tried to address the issue with the taste and flavor of edible insects39,58 but only a few have examined this in the actual insect-based proteins produced or in the final products59,60. The taste and flavor of microbial-based proteins are much less influenced by the type of substrates and the activities of enzymes released by the microbes. The exogenous enzymes further break down carbohydrates and proteins present in the substrate into sugars and peptides and free amino acids which govern the taste and flavor profile of the products. Fungi-based patties were described as salty, sour, bitter, astringent, and umami with a wide range of smells (e.g., nutty, fruity, and moldy)52,61,62. The off-notes of those APs may be reduced by using masking compounds63, but this remains challenging as little is known about the factors influencing the taste and flavor profiles of these proteins nor the molecular interactions among flavor and taste precursors during manufacturing processes and storage. Different proprietary processes from different manufacturers appear to result in unique off-flavor and off-taste characteristics; the strategy to combat this may involve uniquely designing and optimizing batch by batch63. Flavoring agents may be added (Fig. 3) to create a similar sensory profile to its animal-based counterparts, but the control and optimization of flavor blends require close attention64. Due to the aforementioned growing “clean label” trend, natural flavoring additives are now the preferred choice by consumers, but their stability and interaction within the new food matrix needs further evaluation. Ultimately, protein extraction processes from plants, insects, and microorganisms may need to be re-designed to yield proteins with neutral flavors.
Common ingredients of current alternative proteins can be divided into seven groups, including source of proteins, texture enhancers (i.e., binding agents, emulsifiers, thickeners, and stabilizers), fat and oil, fortified nutrients, color and taste additives (i.e., flavoring agents, flavoring agents, taste enhancers), preservatives, and other additives. Pictures of food products are designed by Freepik. https://www.freepik.com/free-psd/detox-smoothie-drink-isolated_151238726.htm.
In terms of cultured meat and seafood, the proteins are derived from actual stem cells of target animals and should, in theory, have fewer taste and flavor issues (Fig. 2d). The concept of this approach evolved around using mammalian and avian cells and tissues to replace land-based animals. The cellular agriculture approach has now been extended to fish, mollusk, and crustacean cells and tissues32,64. Production of cell-based seafood may be well-suited for scalable bioreactor cultivation relative to mammalian muscle tissues due to its unique physiological properties, including tolerance to hypoxia, high buffering capacity, and low-temperature growth conditions of aquaculture cells65. The cells are grown in bioreactors to obtain adequate cell quantities, and can then be harvested for ground and comminuted meat products when matured. Alternatively, the cells are anchored to edible scaffolds, e.g. texturized soy protein66, cellulose67, and salmon gelatin film68, to guide the development of three-dimensional (3D) multicellular structures for whole-muscle products. For the latter case, the lack of a circulatory system restricts the diffusion of nutrients and oxygen throughout the tissues69, complicating the culturing of full-sized whole-muscle meat cuts. The formation of a vascular network is also complex, time-consuming, and expensive70. Another potential means to form whole-muscle meat is to structure whole-muscle meat cuts using bioprinting71,72. Handral et al.71 used extrusion printing in which cells were extruded into filaments or fibers, but the shear stress generated may damage the cell membranes73. Later, the tendon-gel integrated bioprinting technique, proposed by Kang et al.72 was demonstrated to form a Wagyu steak by anchoring cell fibers on tendon gels. The cells had undergone differentiation, followed by assembling fibers and adipose tissue using transglutaminases. However, the steak obtained was still small (5 mm in diameter and 10 mm long). Techno-functional properties and sensory characteristics (i.e., color, texture, and flavor) of traditional meat proteins are strongly governed by muscle composition, thick and thin fiber arrangement, and post-mortem biochemical conversion of muscle to meat. In contrast, cultured cells predominantly contain embryonic or neonatal isoforms of actin and myosin74; the cultured tissues lack fat and collagenous connective tissue structure. Whether cultured meat exhibits a comparable texture to conventional meat still requires further evaluation. The idea of co-culturing several different cell types, such as myoblasts, fibroblasts, and adipocytes, has been proposed in an attempt to better mimic muscle composition. Nonetheless, because different cells grow and differentiate in specific media, changing media might induce sub-optimal conditions for one or more cell types69. The proposed technique along with information regarding the behavior of cultured tissues on texture and on the rate and extent of the tenderization process requires a more thorough investigation69. Production of further processed and comminuted meat products require sufficient protein content with functionality, particularly water-holding capacity, emulsifying, and gelling properties. At present, there is no scientific investigation describing the inherent techno-functional properties of cultured meat and seafood or the effects of further processing on their properties. Similar to other alternative products, processing aids could be added to compensate for incomplete protein functionality. Colorants can also be added to counteract discoloration73. As for visual color, cultured cells contain very low myoglobin content, giving cultured meat a colorless appearance. Color may be adjusted during cell culturing by directly adding pigments into the culture media75 or stimulating myoglobin expression73; however, more investigations are required. As for taste and flavor, it remains unclear whether the precursor compounds in cultured meat would be present in similar quantities as their conventional counterparts73. In addition, the absence of fat will impact flavor development during cooking69. Adding fat and flavoring agents during product manufacturing may help overcome these issues of cultured meat69, but further studies are required. Scaffold materials may also influence the development of the taste and flavor of the products.
The main technological issue of cultured meat and seafood is up-scaling. In Singapore, a commercial cultured meat company possesses a production capacity of 2–3 kg per week compared to the 4000–5000 metric tons of conventional chickens sold weekly in the country76. In the USA, an FDA-approved cultured meat company addressed its production size of cultured chicken meat at approximately 25 tons annually77 while approximately 2.9 million tons of chicken meats were produced nationally in 202178. Large-scale production of cultured meat and seafood requires tightly controlled bioreactors, as slight variations in the growing conditions may cause massive production and contamination risks42. The currently available process is considered time and resource-intensive and is far from being economically viable47. Overall, the technology is far from being scalable or economically feasible.
Nutritional profile
One of the benefits of APs have been associated with is health promotion. This is based upon the assumed reduced risk of chronic diseases brought by the consumption of red and processed meat, containing high saturated fat, cholesterol, and low fiber79. However, despite the well-documented benefits of plant-based diets for health80,81,82, critical evaluation of the effects of APs on health implications is still scarce and the fact that many are now classified under the heading of ‘ultra-processed foods’ is of substantial concern83. So far, consumers are still very hesitant to trust that such products are truly healthy and nutritious84.
In terms of AP products, recent studies have systematically analyzed the nutritional profiles of commercially available products based on their product nutrition labels (Table 2). Alternative products show lower energy density and saturated fat with higher dietary fiber than their animal-based counterparts. However, the products often contain more salt than their conventional counterparts85,86,87. Most plant-based products consist of lower protein content whereas insect-based and microbe-derived meat analogs show similar protein levels to their counterparts88. Commercial alternative products are often formulated based on extracted proteins along with other ingredients, including oils, flavoring, and coloring agents (Fig. 3) to create the visual, structure, and sensation of being derived from animals84,89. Based on their formulation, alternative products are often classified as ultra-processed foods83. Although a number of observational studies show a link between ultra-processed foods and diet-related adverse health effects83, further causational investigation is required to address this point. In addition, given that the health benefits of plant consumption are from biometabolites, (e.g., polyphenols), the extensive protein extraction and food processing may greatly influence their presence along with other bioactivities89. Hence, whether the alternative products are healthier diet choices than conventional animal-based proteins requires further scientific evidence.
Considering the nutritional profile of each AP, plant proteins are often considered low in protein quality mainly due to their lower content of essential amino acids, particularly lysine and sulfur-containing amino acids compared to animal-based protein90,91,92. A previous study by Gorissen et al.93 reported essential amino acids content in commercially available plant-based protein isolates and found that only the products from soy (27% of total amino acid), brown rice (28%), pea (30%), corn (32%), and potato (37%) met the FAO/WHO requirements for essential amino acids. Oat (21% of total protein), lupin (21%), wheat (22%), and hemp (23%) were found to be below the requirement. Such problems could be overcome by blending different plant protein sources94. However, with the commercially available proteins, the target content of lysine along with isoleucine and leucine would be limiting constraints94,95. Plant-based drinks and formulas are not recommended as main liquid foods for children <1 years of age96. In the case of insect-based proteins, their essential amino acids appear to meet the FAO/WHO requirement22, however, the amino acid composition differs largely between species97, the origin of the insects, different feeding regimes, and methods of analyses employed98. As for microbe-derived proteins, the information regarding their nutritional profiles is still very limited. For mycoprotein, in most reported microbe-derived proteins, their amino acid profiles and essential amino acid contents were similar to those of chicken meat99 with protein digestibility corrected amino acid scores (PDCAAS) of 0.9100,101. However, these products show higher calories, protein, fat, dietary fiber, and carbohydrate than chicken meat99. It is worth noting that insects and mycoproteins comprise high chitin content102 which could lead to an overestimation of the protein concentration103. Even though cultured meat and seafood are grown in vitro from cultivated animal cells, their nutritional profiles remain to be elucidated. An investigation into the protein content, amino acid profiles, and protein digestibility of cultured meat and seafood is required. The nutritional profile of the scaffold also needs to be taken into consideration73.
Animal-based products are also considered good sources of micronutrients, particularly vitamin B12, iron, zinc, and trace minerals. However, vitamin B12 is absent in plant-based products and the other minerals appear to be relatively low in plant-based alternatives92, microbe-derived25, and cultured meat104. These compounds can be fortified into the final products but the biological efficacy of added inorganic minerals under the formulated condition requires further investigation91,103. Potential enrichment of micronutrients in mycoprotein through supplementation in the growth medium is possible and remains to be examined25. As for cultured meat, mechanisms of micronutrient uptake into the cultured cells also remains to be elucidated105. Above all, further investigation on whether the fortified micronutrients through those technologies provide similar benefits in human health at different age ranges is necessary to make properly informed decisions.
Safety: allergens and contaminants
A major concern of APs is whether the protein is safe for human consumption. Despite their long history of consumption, the behavior of plant-based and insect-based proteins under different manufacturing processes as novel ingredients may differ from their conventional uses. Heavy metals (e.g., lead, arsenic, mercury, and cadmium), pesticide residues, mycotoxins, and pathogenic microorganisms may be carried over from raw materials106,107 or from substrates in the case of microbe-derived proteins108. The main concerns for microbe-derived proteins are toxic metabolites produced by the microbes and contamination of undesirable microorganisms109. Little is known about the effects of processing on such contaminants.
Of all the potential health hazards, the issues of allergens are particularly concerning. Exposure to new forms of food produced using AP-focused techniques may introduce unknown allergenic responses among susceptible consumers. For plant-based proteins, nuts, soybeans, and wheat are among the well-documented eight most common food allergens110, but little is known about other emerging plant-based proteins, such as those derived from peas and mung beans. Safety prediction could be performed by comparing amino acid sequences of a novel protein against known allergens; however, the current allergen sequence databases are insufficient for proper and robust safety assessments111. Insect-based proteins also contain known allergenic compounds (e.g., arginine kinase, and tropomyosin) but their clinical significance remains to be elucidated46. In 2021, the EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA) raised the risk of allergy to yellow mealworm proteins, particularly among consumers who are allergic to crustaceans112. Despite the direct reports on the allergenicity of microbe-derived proteins, the cases of microbe-based foods suggest that the allergenic potent of the novel proteins requires close attention113,114. The risks also extend to microbe-derived recombinant protein analogs. Indeed, some of those precision-fermentation products, e.g., human milk oligosaccharides derived from modified E. coli, meat-flavor soy leghemoglobin produced by engineered Komagataella phaffii, and casein from engineered Saccharomyces cerevisiae, have received FDA approval to commercialized in the US115. Allergenicity risks of the precision-fermentation technology itself are recently underpinned by the Food Systems and Food Safety Division of FAO116. This is due to the lack of full comprehension of the metabolites of the modified microbes; whether they produce existing allergens, alter proteins to be allergenic, or novel compounds still not known as allergens116. Although many allergens are heat labile and can be inactivated during thermal processing, the allergenicity of some known allergens remains unaltered after thermal treatment117,118,119,120. This issue was observed for prolamin, the largest allergenic plant protein family, and tropomyosin, a major allergen in crustaceans and potentially insects120. In addition, research describing the effects of thermal processing on the allergenicity of the novel proteins is still limited. Above all, these APs are used in food products in the form of protein isolates (70–95% protein), protein concentrates (60–70% protein), and protein hydrolysates (90–95% protein) which contain higher protein loads than their natural forms. Frequent exposure at a high concentration of those ingredients may trigger allergenic reactions in susceptible consumers120.
Plants and insects that are common sources of APs often carry antinutrients. Plant antinutrients, such as protease inhibitors (e.g., trypsin inhibitors), polyphenols (e.g., tannins), and phytates, generally interfere absorption and utilization of nutrients. In some cases, however, stronger effects may include a leaky gut, autoimmune diseases (e.g., lectins and some saponins), gut dysfunction, inflammation, and behavioral effects121. As for insects, the levels of antinutrients (e.g., hydrocyanide (2.2–3.2 mg/kg)), oxalate (13.2–28.4 mg/kg), phytate (0.3 mg/kg), and tannin (0.3–0.4 mg/kg) fall within acceptable limits22. However, the negative impacts of antinutrients are usually diminished after the ingredients are processed under appropriate processing conditions46,120,122.
Other potentially hazardous compounds can be formed when the proteins are processed at high temperatures106. Maillard reaction developed under dry heating was shown to result in the formation of new epitopes in wheat123 and nuts124,125. Further processing may result in the accumulation of advanced glycation end-products which are shown to increase the expression of pro-inflammatory cytokines in mammalian cells126. Glycation of pea protein with glucose and lactose could interfere with trypsin activity127, hence potentially reducing the bioavailability of proteins. More research is needed to elucidate this issue.
The main concerns for microbe-derived proteins are toxic metabolites produced by the microbes and contamination of undesirable microorganisms128. Mycotoxins are a group of toxic substances, produced by filamentous fungi, which are of concern for food safety, as they may cause harmful effects on the human organism and accumulate in the tissues of some animals. However, research on mycotoxins contamination in APs is still limited. The first study on mycotoxins occurrence and its exposure assessment in plant-based meat alternatives samples from Italy was conducted by Mihalache et al.129. Results showed that most of the samples (92%) were contaminated with at least one mycotoxin and mixtures of up to seven mycotoxins. Additionally, consumption of plant-based meat alternatives led to a non-tolerable exposure to alternariol (i.e., a toxic metabolite of Alternaria fungi) for vegan and vegetarian consumers, while samples contaminated with aflatoxins and ochratoxin A, indicated a health concern related to liver and renal cancer, respectively. Therefore, contamination with mycotoxins in APs, particularly plant-based protein alternatives, should be carefully monitored and controlled by producers and competent authorities.
For cultured meat and seafood, the current literature lacks a direct assessment with respect to food safety. In theory, they are less susceptible to microbial contamination, pesticides, and heavy metals relative to conventional animal-based meat130. However, potential hazards may arise from the source of the animal cells and cell culture media. There is the possibility that the cultured cells may carry zoonotic disease agents (e.g., parasites, viruses, pathogens, and infectious prions) and without a broad level screening of cell lines prior to ensure no infectious agents is present will present a substantial risk130. In addition, when cells are stressed, which is often the case in cell culture there is the potential for the release of histamine130,131,132. Some of those biological agents may be able to propagate or persist under certain processing conditions133. The accumulation of this in the final product is possible as histamine is known to be heat-resistant134. There are quite a large number of people who are intolerant to histamine and can suffer adverse health effects due to exposure135.
In the case that genetically modified cells are used, genomic stability particularly after continual sub-culturing for multiple passages must be assessed136. During cell cultivation, the concentration of any substances in the media, both intended (e.g., fetal bovine serum) and unintended (e.g., cell-secreted growth factors, and histamine) can accumulate, leading to high concentrations of those substances130. The biological response due to the consumption of those compounds at such levels is still not fully understood. In addition, whether chemical and structural changes of either the cells, scaffolds, and medium residues during food manufacturing affect human health requires further investigation137.
Regulatory framework
The lack of clear and transparent standards and guidelines at both national and international levels regarding APs is considered one of the key issues slowing down progress in the industry. The most essential reason for the legislative framework is the assurance of the safety of consumers and fair trade among food companies across countries138. The regulatory frameworks must also include labeling of the products so that consumers can easily make their informed choices.
APs are likely to be regulated as novel foods, i.e., foods and food ingredients that do not have a history of safe use, and regulatory status regarding novel foods differs across countries. In the EU, the European Commission (EC) novel food legislation regulation (EC 2015/2283) has been issued and has been in force since 2018139. As for the USA, there is no specific definition or regulation for novel foods138. Instead, the US Food and Drug Administration (USFDA) considers any new food ingredients as food additives or generally recognizes as safe (GRAS) for specific intended use. USFDA has recently issued a draft guidance on “Labeling of Plant-Based Milk Alternatives (PBMA) and Voluntary Nutrient Statements” on February 2023 with the goal to assist PBMA producers in providing consumers with clear labeling140.
The regulatory status regarding novel foods in Asia is somewhat behind Europe and the USA. Only China, South Korea, Singapore, and Thailand have specific regulations for novel foods. The regulation of novel foods in China resembles the EU model141. As for South Korea, novel ingredients are registered under the Temporary Standards and Regulations for Food Ingredients (MFDS Notification No.2016–27). The record shows that in 2017, there were 20 cases that have been approved as novel ingredients, including insects, plants, microorganisms, and sweeteners142. In August 2023, South Korea issued a draft amendment that will legally enable plant-based meat alternatives to use the word “meat” on their labels143. Recently later, they have officially published the Standards for Recognition of Temporary Standards and Specifications for Food which recognizes cell and microbial culture as food ingredients144.
In contrast to less specific regulations among these countries with regard to novel foods, the Singapore Food Agency (SFA) and Thai Food and Drug Administration (FDA) have more specific safety assessment criteria and guidance on APs145. SFA requires a safety assessment of potential human health hazards of the novel ingredients, both in their most basic form as well as at the level of actual food products and conditions during consumption. In addition, it is the responsibility of companies to adopt effective testing methodologies in compliance with international standards (e.g., ISO/IEC 17025) based on the hazards that may be present in the novel foods. On the other hand, the Thai FDA requires a sub-chronic study or at the minimum a clinical research study in healthy people for safety assessment145.
Future trends and opportunities
The growing trend of APs opens opportunities for new protein sources as well as technological innovations (Fig. 4). The issues of nutritional quality, technological properties, and allergenicity of the currently used APs will serve to drive the search for diversifying protein sources. Algae, seaweed, and water plants are of interest as new protein sources due to their rapid growth, high protein content, and unique nutritional profiles. An example is Wolffia spp., an aquatic plant of the duckweed family, which offers nine essential amino acids146 with a PDCAAS score of 0.89147, dietary fiber, several trace minerals148, and bioactive vitamin B12149. Scientists and the food industry have been exploring potential uses of their indigenous plants such as Bambara groundnut, a pulse crop largely cultivated in West Africa149,150,151. The use of local produce may not only be favorable due to crop tolerance but also align with the aim to reduce carbon footprint during the export and import of non-local protein ingredients. Given a wide variety of APs accompanied by an increase in data about food, the formulation of protein blends can serve the nutritional demands of many93,95. In addition, oilseeds and vegetable byproducts, such as sunflower, potato, and chickpea, from food manufacturing can be upcycled to produce protein ingredients. Such practices not only help support food security but also the goal of having a sustainable global food supply system.
Dat-line arrows connect between challenging issues of alternative proteins with their potential solutions.
With diversifying protein sources comes better technology-assisted protein extraction and protein recovery, which can be developed further for maximum production efficiency152. An application of supercritical fluid extraction using CO2 and ethanol, for example, has been reported to remove the off-flavor compounds from pea protein isolates153. High-pressure processing has been shown to improve penetration of extraction solvent within the cell, hence increasing yield without altering protein functionalities154.
In terms of cultured meat and seafood, immortal cell lines have been developed through advanced gene-editing technology in order to increase proliferative capacity155. However, cell characteristics, metabolic activities, along with genetic stability, and scalability require further assessment. Cell culture medium, edible micro-carriers, and scaffolding materials are also under extensive investigation155. Fermentation has been one of the key technologies employed to produce ingredients for APs and will continue to play an important role in this industry156. This includes the use of precision-fermentation-based “cell factories” for the production of replacement ingredients for dairy and egg proteins157, pigments of meat analogs158, and the off-flavor masking agents for plant-based proteins159. The beneficial effects of fermentation on removing unpleasant beany off-flavors are under extensive investigation158,160,161, due to its high efficiency, reduced harm to the protein matrix, targeted performance, and low budget requirements159. In addition, the utilization of proper microorganisms can also improve the aroma profile of the final products158,161. Nevertheless, redesigns of bioreactors for food-grade fermentation, minimizing downstream purification, and maximizing value extraction from left-over microbial biomass are required for a techno-economically feasible approach. Cost-effective up-scaling production of APs and their components is essential to reduce the price of the final products to gain consumer attraction.
While most scientific studies primarily aim at technological improvements, more studies on the safety and health effects are required. Research regarding the reduction of allergenicity in APs is underway but much still needs to be understood. Enzymatic reactions, either based on enzymatic cross-linking by transglutaminase162,163 or protein hydrolysis164,165, have been shown to reduce the allergenicity of soy, wheat proteins, and peanut proteins. A different approach to understanding the effect of introducing APs to a broad population is to look at its association with various, distinct metabolic processes, rather than the disease itself. In addition, with food transformation towards APs, it is possible to cause a shift in the gut microbiome166,167, which could cause changes to the body’s physiology. The development of serum-free medium and edible scaffolds for cultured meat and seafood production is also being explored168. Furthermore, the need for effective and affordable analytical methods to detect and verify levels of allergens, toxins, and other contaminants in the finished food product is urgently required. Standards and guidelines, including labeling, for APs have been discussed by the FAO/WHO as well as adhering bodies in many countries, and are needed to ensure the safety of consumers to a growing number of new food products116.
Data availability
All relevant data are available from the authors upon a reasonable request.
References
Ehrlich, P. R. & Harte, J. To feed the world in 2050 will require a global revolution. Proc. Natl Acad. Sci. USA 112, 14743–14744 (2015).
Rome. UN report: pandemic year marked by spike in world hunger. World Health Organization https://www.who.int/news/item/12-07-2021-un-report-pandemic-year-marked-by-spike-in-world-hunger (2021).
Thavamani, A., Sferra, T. J. & Sankararaman, S. Meet the meat alternatives: the value of alternative protein sources. Curr. Nutr. Rep. 9, 346–355 (2020).
Xu, X. et al. Global greenhouse gas emissions from animal-based foods are twice those of plant-based foods. Nat. Food 2, 724–732 (2021).
Llor, C. & Bjerrum, L. Antimicrobial resistance: risk associated with antibiotic overuse and initiatives to reduce the problem. Ther. Adv. Drug Saf. 5, 229–241 (2014).
Mariott, I. F. & Gardner, C. D. Dietary protein and amino acids in vegetarian diets-a review. Nutrients 11, 2661 (2019).
Halloran, A., Hanboonsong, Y., Roos, N. & Bruun, S. Life cycle assessment of cricket farming in north-eastern Thailand. J. Clean. Prod. 156, 83–94 (2017).
Van Huis, A. & Oonincx, D. G. A. B. The environmental sustainability of insects as food and feed. a review. Agron. Sustain. Dev. 37, 43 (2017).
Onwezen, M. C., Bouwman, E. P., Reinders, M. J. & Dagevos, H. A systematic review on consumer acceptance of alternative proteins: pulses, algae, insects, plant-based meat alternatives, and cultured meat. Appetite 159, 105058 (2021).
Witte, B. et al. The protein transformation. Food For Thought https://web-assets.bcg.com/a0/28/4295860343c6a2a5b9f4e3436114/bcg-food-for-thought-the-protein-transformation-mar-2021.pdf (2021).
Grand View Research. Alternative protein market size, share & trends analysis report. Food Alternative Protein Market Report https://www.grandviewresearch.com/industry-analysis/alternative-protein-market-report (2024).
O’Donnell, M. & Murray, S. A deeper dive into alternative protein investments in 2022: the case for optimism. Good Food Institute https://gfi.org/blog/alternative-protein-investments-update-and-outlook/ (2023).
Verbeke, W. et al. Would you eat cultured meat?’: consumers’ reactions and attitude formation in Belgium, Portugal and the United Kingdom. Meat Sci. 102, 49–58 (2015).
Godschalk-Broers, L., Sala, G. & Scholten, E. Meat analogues: relating structure to texture and sensory perception. Foods 11, 2227 (2022).
Malek, L. & Umberger, W. J. Protein source matters: understanding consumer segments with distinct preferences for alternative proteins. Future Foods 7, 100220 (2023).
Lee, H. J., Yong, H. I., Kim, M., Choi, Y. S. & Jo, C. Status of meat alternatives and their potential role in the future meat market - a review. Asian-Australas J. Anim. Sci. 33, 1533–1543 (2020).
FAO. The need for guidance on alternative proteins highlighted to Codex Alimentarius Commission. Food and Agriculture Organization of the United Nations https://www.fao.org/in-action/sustainable-and-circular-bioeconomy/resources/news/details/en/c/1459357/ (2021).
Wiener-Bronner, D. Lab-grown meat is cleared for sale in the United States. Food and Agriculture Organization of the United Nations https://www.fao.org/in-action/sustainable-and-circular-bioeconomy/resources/news/details/en/c/1459357/ (2023).
Tilman, D. & Clark, M. Global diets link environmental sustainability and human health. Nature 515, 518–522 (2014).
Raheem, D. et al. Entomophagy: nutritional, ecological, safety and legislation aspects. Food Res. Int. 126, 108672 (2019).
Oonincx, D. G. et al. An exploration on greenhouse gas and ammonia production by insect species suitable for animal or human consumption. PLoS ONE 5, e14445 (2010).
Smetana, S. et al. Meat alternatives: life cycle assessment of most known meat substitutes. Int. J. Life Cycle Assess. 20, 1254–1267 (2015).
Mejia, M. A. et al. Life cycle assessment of the production of a large variety of meat analogs by three diverse factories. J. Hunger Environ. Nutr. 5, 1–13 (2019).
Järviö, N., Maljanen, N. L., Kobayashi, Y., Ryynänen, T. & Tuomisto, H. L. An attributional life cycle assessment of microbial protein production: a case study on using hydrogen-oxidizing bacteria. Sci. Total Environ. 776, 145764 (2021).
Souza Filho, P. F. et al. Vegan-mycoprotein concentrate from pea-processing industry byproduct using edible filamentous fungi. Fungal Biol. Biotechnol. 5, 5 (2018).
Stoffel, F. et al. Production of edible mycoprotein using agroindustrial wastes: influence on nutritional, chemical and biological properties. Innov. Food Sci. Emerg. Technol. 58, 102227 (2019).
Treich, N. Cultured meat: promises and challenges. Environ. Resour. Econ. 79, 33–61 (2021).
Rischer, H., Szilvay, G. R. & Oksman-Caldentey, K. M. Cellular agriculture - industrial biotechnology for food and materials. Curr. Opin. Biotechnol. 61, 128–134 (2020).
Sinke, P. et al. Ex-ante life cycle assessment of commercial-scale cultivated meat production in 2030. Int. J. Life Cycle Assess. 28, 234–254 (2023).
Mattick, C. S., Landis, A. E., Allenby, B. R. & Genovese, N. J. Anticipatory life cycle analysis of in vitro biomass cultivation for cultured meat production in the United States. Environ. Sci. Technol. 49, 11941–11949 (2015).
Rodríguez Escobar, M. I. et al. Analysis of the cultured meat production system in function of its environmental footprint: current status, gaps and recommendations. Foods 10, 2941 (2021).
Goswami, M. et al. Cellular aquaculture: prospects and challenges. Micromachines 13, 828 (2022).
Moss, R. et al. A prospective review of the sensory properties of plant-based dairy and meat alternatives with a focus on texture. Foods 12, 1709 (2023).
McClements, D. J. & Grossmann, L. A brief review of the science behind the design of healthy and sustainable plant-based foods. NPJ Sci. Food 5, 17 (2021).
Sim, S. Y. J., SRV, A., Chiang, J. H. & Henry, C. J. Plant proteins for future foods: a roadmap. Foods 10, 1967 (2021).
Munialo, C. D., Martin, A. H., Van Der Linden, E. & De Jongh, H. H. Fibril formation from pea protein and subsequent gel formation. J. Agric. Food Chem. 62, 2418–2427 (2014).
Yi, L. et al. Extraction and characterisation of protein fractions from five insect species. Food Chem. 141, 3341–3348 (2013).
Kim, T.-K. et al. Thermal stability and rheological properties of heat-induced gels prepared using edible insect proteins in a model system. LWT 134, 110270 (2020).
Mishyna, M., Keppler, J. K. & Chen, J. Techno-functional properties of edible insect proteins and effects of processing. Curr. Opin. Colloid Interface Sci. 56, 101508 (2021).
Queiroz, L. S. et al. Edible insect as an alternative protein source: a review on the chemistry and functionalities of proteins under different processing methods. Heliyon 9, e14831 (2023).
Bakhsh, A. et al. Quality characteristics of meat analogs through the incorporation of textured vegetable protein: a systematic review. Foods 11, 1242 (2022).
Dekkers, B. L., Boom, R. M. & van der Goot, A. J. Structuring processes for meat analogues. Trends Food Sci. Technol. 81, 25–36 (2018).
Smetana, S. et al. Structure design of insect-based meat analogs with high-moisture extrusion. J. Food Eng. 229, 83–85 (2018).
Sha, L. & Xiong, Y. L. Plant protein-based alternatives of reconstructed meat: science, technology, and challenges. Trends Food Sci. Technol. 102, 51–61 (2022).
Ettinger, L. et al. Consumer perception and acceptability of plant-based alternatives to chicken. Foods 11, 2271 (2022).
Hadi, J. & Brightwell, G. Safety of alternative proteins: technological, environmental and regulatory aspects of cultured meat, plant-based meat, insect protein and single-cell protein. Foods 10, 1226 (2021).
Schmid, E., Farahnaky, A., Adhikari, B. & Torley, P. J. High moisture extrusion cooking of meat analogs: a review of mechanisms of protein texturization. Compr. Rev. Food Sci. Food Saf. 6, 4573–4609 (2022).
Cornet, S. H. V. et al. Thermo-mechanical processing of plant proteins using shear cell and high-moisture extrusion cooking. Crit. Rev. Food Sci. Nutr. 62, 3264–3280 (2022).
Sethi, S., Tyagi, S. K. & Anurag, R. K. Plant-based milk alternatives an emerging segment of functional beverages: a review. J. Food Sci. Technol. 53, 3408–3423 (2016).
Boukid, F. & Gagaoua, M. Vegan egg: a future-proof food ingredient? Foods 11, 161 (2022).
Plamada, D. et al. Plant-based dairy alternatives-a future direction to the Milky Way. Foods 12, 1883 (2023).
Gamarra-Castillo, O., Echeverry-Montaña, N., Marbello-Santrich, A., Hernández-Carrión, M. & Restrepo, S. Meat substitute development from fungal protein (Aspergillus oryzae). Foods 11, 2940 (2022).
Durkin, A. et al. Can closed-loop microbial protein provide sustainable protein security against the hunger pandemic? Curr. Res. Biotechnol. 4, 365–376 (2022).
Ribeiro, G. O. et al. Innovations and developments in single cell protein: bibliometric review and patents analysis. Front. Microbiol. 13, 1093464 (2023).
Moura, M. A. F., Alves, V. S. & Takahashi, J. A. Nutritional quality, techno-functional characteristics, and safety of biomass powder and protein isolate produced from Penicillium maximae. Foods 11, 3621 (2022).
Santo, R. E. et al. Considering plant-based meat substitutes and cell-based meats: a public health and food systems perspective. Front. Sustain. Food Syst. 4, 134 (2020).
Tao, A. et al. Mechanism and application of fermentation to remove beany flavor from plant-based meat analogs: a mini review. Front. Microbiol. 13, 1070773 (2022).
Kouřimská, L. & Adámková, A. Nutritional and sensory quality of edible insects. NFS J. 4, 22–26 (2016).
Rudy Caparros Megido, R. C. et al. Consumer acceptance of insect-based alternative meat products in Western countries. Food Qual. Prefer. 52, 237–243 (2016).
Schouteten, J. J. et al. Emotional and sensory profiling of insect-, plant- and meat-based burgers under blind, expected and informed conditions. Food Qual. Prefer. 52, 27–31 (2016).
Hellwig, C., Gmoser, R., Lundin, M., Taherzadeh, M. J. & Rousta, K. Fungi burger from stale bread? A case study on perceptions of a novel protein-rich food product made from an edible fungus. Foods 9, 1112 (2020).
Rousta, N. et al. Filamentous fungus Aspergillus oryzae for food: from submerged cultivation to fungal burgers and their sensory evaluation-a pilot study. Foods 10, 2774 (2021).
Ismail, I., Hwang, Y.-H. & Joo, S.-T. Meat analog as future food: a review. J. Anim. Sci. Technol. 62, 111 (2020).
Kale, P., Mishra, A. & Annapure, U. S. Development of vegan meat flavour: a review on sources and techniques. Future Foods 5, 100149 (2022).
Rubio, N., Datar, I., Stachura, D., Kaplan, D. & Krueger, K. Cell-based fish: a novel approach to seafood production and an opportunity for cellular agriculture. Front. Sustain. Food Syst. 3, 43 (2019).
Ben-Arye, T. et al. Textured soy protein scaffolds enable the generation of three-dimensional bovine skeletal muscle tissue for cell-based meat. Nat. Food 1, 210–220 (2020).
Ahmad, K. et al. Extracellular matrix and the production of cultured meat. Foods 10, 3116 (2021).
Orellana, N. et al. A new edible film to produce in vitro meat. Foods 9, 185 (2020).
Fraeye, I., Kratka, M., Vandenburgh, H. & Thorrez, L. Sensorial and nutritional aspects of cultured meat in comparison to traditional meat: much to be inferred. Front. Nutr. 7, 35 (2020).
Knežic, T., Janjuševic, L., Djisalov, M., Yodmuang, S. & Gadjanski, I. Using vertebrate stem and progenitor cells for cellular agriculture, state-of-the-art, challenges, and future perspectives. Biomolecules 12, 699 (2022).
Handral, H. K., Hua Tay, S., Wan Chan, W. & Choudhury, D. 3D printing of cultured meat products. Crit. Rev. Food Sci. Nutr. 62, 1–10 (2020).
Kang, D. H. et al. Engineered whole cut meat-like tissue by the assembly of cell fibers using tendon-gel integrated bioprinting. Nat. Commun. 12, 1–12 (2021).
Broucke, K., Van Pamel, E., Van Coillie, E., Herman, L. & Van Royen, G. Cultured meat and challenges ahead: a review on nutritional, technofunctional and sensorial properties, safety and legislation. Meat Sci. 195, 109006 (2023).
Thorrez, L. & Vandenburgh, H. Challenges in the quest for ‘clean meat. Nat. Biotechnol. 37, 215–216 (2019).
Simsa, R. et al. Extracellular heme proteins influence bovine myosatellite cell proliferation and the color of cell-based meat. Foods 8, 521 (2019).
Marsh, N. Why Singapore is the only place in the world selling lab-grown meat? BBC News https://www.bbc.com/news/business-65784505 (2023).
Torrella K. Cell-cultivated chicken was just approved for sale in the US. but it won’t be on grocery shelves anytime soon. Vox Media https://www.vox.com/future-perfect/23768224/eat-just-good-meat-upside-cell-cultivated-chicken-lab-grown (2023).
USDA. Poultry - production and value 2020 summary. National Agricultural Statistics Service https://www.nass.usda.gov/Publications/Todays_Reports/reports/plva0421.pdf (2021).
Vatanparast, H., Islam, N., Shafiee, M. & Ramdath, D. D. Increasing plant-based meat alternatives and decreasing red and processed meat in the diet differentially affect the diet quality and utrient intakes of Canadians. Nutrients 12, 2034 (2020).
Lin, Y. et al. Dietary animal and plant protein intakes and their associations with obesity and cardio-metabolic indicators in European adolescents: the HELENA cross-sectional study. Nutr. J. 14, 10 (2015).
Li, S. S. et al. Effect of plant protein on blood lipids: a systematic review and meta-analysis of randomized controlled trials. J. Am. Heart Assoc. 6, e006659 (2017).
Andersen, V., Halekoh, U., Tjonneland, A., Vogel, U. & Kopp, T. I. Intake of red and processed meat, use of non-steroid anti-inflammatory drugs, genetic variants and risk of colorectal cancer: a prospective study of the Danish “diet, cancer and health” cohort. Int. J. Mol. Sci. 20, 1121 (2019).
Monteiro, C. A., Cannon, G., Lawrence, M., Costa Louzada, M. L. & Pereira Machado, P. Ultra-processed foods, diet quality, and health using the NOVA classification system. Food and Agriculture Organization of the United Nations https://www.fao.org/3/ca5644en/ca5644en.pdf (2019).
Bohrer, B. M. An investigation of the formulation and nutritional composition of modern meat analogue products. Food Sci. Hum. Wellness 8, 320–329 (2019).
Alessandrini, R. et al. Nutritional quality of plant-based meat products available in the UK: a cross-sectional survey. Nutrients 13, 4225 (2021).
Boukid, F. et al. Seafood alternatives: assessing the nutritional profile of products sold in the global market. Eur. Food Res. Technol. 248, 1777–1786 (2022).
Švarc, P. L. et al. Nutrient content in plant-based protein products intended for food composition databases. J. Food Compos. Anal. 106, 104332 (2022).
Smetana, S., Profeta, A., Voigt, R., Kircher, C. & Heinz, V. Meat substitution in burgers: nutritional scoring, sensorial testing, and life cycle assessment. Future Foods 4, 100042 (2021).
Toh, D. W. K., SRV, A. & Henry, C. J. Unknown impacts of plant-based meat alternatives on long-term health. Nat. Food 3, 90–91 (2022).
Mathai, J. K., Liu, Y. & Stein, H. H. Values for digestible indispensable amino acid scores (DIAAS) for some dairy and plant proteins may better describe protein quality than values calculated using the concept for protein digestibility-corrected amino acid scores (PDCAAS). Br. J. Nutr. 117, 490–499 (2017).
Ahmad, H. et al. Plant-based meat alternatives: compositional analysis, current development and challenges. Appl. Food Res. 2, 100154 (2022).
Smith, N. W., Dave, A. C., Hill, J. P. & McNabb, W. C. Nutritional assessment of plant-based beverages in comparison to bovine milk. Front. Nutr. 9, 957486 (2022).
Gorissen, S. H. M. et al. Protein content and amino acid composition of commercially available plant-based protein isolates. Amino Acids 50, 1685–1695 (2018).
Dimina, L., Rémond, D., Huneau, J.-F. & Mariotti, F. Combining plant proteins to achieve amino acid profiles adapted to various nutritional objectives-an exploratory analysis using linear programming. Front. Nutr. 8, 809685 (2022).
Woolf, P. J., Fu, L. L. & Basu, A. Protein: identifying optimal amino acid complements from plant-based foods. PLoS ONE 6, e18836 (2011).
Brusati, M., Baroni, L., Rizzo, G., Giampieri, F. & Battino, M. Plant-based milk alternatives in child nutrition. Foods 12, 1544 (2023).
Rumpold, B. A. & Schlüter, O. K. Nutritional composition and safety aspects of edible insects. Mol. Nutr. Food Res. 57, 802–823 (2013).
Aguilar-Toalá, J. E., Cruz-Monterrosa, R. G. & Liceaga, A. M. Beyond human nutrition of edible insects: health benefits and safety aspects. Insects 13, 1007 (2022).
Coelho, M. O. C. et al. Mycoprotein as a possible alternative source of dietary protein to support muscle and metabolic health. Nutr. Rev. 78, 486–497 (2020).
Finnigan, T. J. A. et al. Mycoprotein: the future of nutritious nonmeat protein, a symposium review. Curr. Dev. Nutr. 3, nzz021 (2019).
Schweiggert-Weisz, U., Eisner, P., Bader-Mittermaier, S. & Osen, R. Food proteins from plants and fungi. Curr. Opin. Food Sci. 32, 156–162 (2020).
Bottin, J. H. et al. Mycoprotein reduces energy intake and postprandial insulin release without altering glucagon-like peptide-1 and peptide tyrosine-tyrosine concentrations in healthy overweight and obese adults: a randomised-controlled trial. Br. J. Nutr. 116, 360–374 (2016).
Luparelli, A. V. et al. Development of a quantitative UPLC-ESI/MS method for the simultaneous determination of the chitin and protein content in insects. Food Anal. Methods 16, 252–265 (2023).
Post, M. J., & Hocquette, J.-F. New sources of animal proteins: cultured meat. In New Aspects of Meat Quality - From Genes to Ethics (ed. Purslow, P. P.) 425–441 (Woodhead Publishing Limited, 2017).
Chriki, S. & Hocquette, J.-F. The myth of cultured meat: a review. Front. Nutr. 7, 7 (2020).
Banach, J. L., Hoek-van den Hil, E. F. & van der Fels-Klerx, H. J. Food safety hazards in the European seaweed chain. Compr. Rev. Food Sci. Food Saf. 19, 332–364 (2020).
Meyer, A. M., Hoek-van den Hil, E. F. & van der Fels-Klerx, H. J. Chemical food safety hazards of insects reared for food and feed. J. Insects Food Feed 7, 1–10 (2022).
Salazar-López, N. J. et al. Single-cell protein production as a strategy to reincorporate food waste and agro by-products back into the processing chain. Bioengineering 9, 623 (2022).
Ritala, A., Häkkinen, S. T., Toivari, M. & Wiebe, M. G. Single cell protein-state-of-the-art, industrial landscape and patents 2001-2016. Front. Microbiol. 8, 2009 (2017).
FDA. Food allergies. Food and Drug Administration https://www.fda.gov/food/food-labeling-nutrition/food-allergies (2023).
Fernandez, A., Mills, E. N. C., Koning, F. & Moreno, F. J. Allergenicity assessment of novel food proteins: what should be improved? Trends Biotechnol. 39, 4–8 (2021).
Turck, D. et al. Safety of dried yellow mealworm (Tenebrio molitor larva) as a novel food pursuant to regulation (EU) 2015/2283. EFSA J. 19, 1–29 (2021).
Yim, H. E. et al. Acute tubulointerstitial nephritis following ingestion of Chlorella tablets. Pediatr. Nephrol. 22, 887–888 (2007).
Petrus, M., Culerrier, R., Campistron, M., Barre, A. & Rougé, P. First case report of anaphylaxis to spirulin: identification of phycocyanin as responsible allergen. Allergy 65, 924–925 (2009).
Samarasiri, M., Chai, K. F. & Chen, W. N. Forward-looking risk assessment framework for novel foods. Food Humanit. 1, 500–513 (2023).
FAO. Food safety foresight technical meeting on new food sources and production systems. Food and Agriculture Organization of the United Nations https://www.fao.org/3/cc8832en/cc8832en.pdf (2023).
Lepski, S. & Brockmeyer, J. Impact of dietary factors and food processing on food allergy. Mol. Nutr. Food Res. 57, 145–152 (2013).
Usui, M. et al. Contribution of structural reversibility to the heat stability of the tropomyosin shrimp allergen. Biosci. Biotechnol. Biochem. 77, 948–953 (2013).
Cabanillas, B., Jappe, U. & Novak, N. Allergy to peanut, soybean, and other legumes: recent advances in allergen characterization, stability to processing and IgE cross-reactivity. Mol. Nutr. Food Res. 62, 1700446 (2017).
Hertzler, S. R., Lieblein-Boff, J. C., Weiler, M. & Allgeier, C. Plant proteins: assessing their nutritional quality and effects on health and physical function. Nutrients 12, 3704 (2020).
Popova, A. & Mihaylova, D. Antinutrients in plant-based foods: a review. Open Biotechnol. J. 13, 68–76 (2019).
Shi, L., Mu, K., Arntfield, S. D. & Nickerson, M. T. Changes in levels of enzyme inhibitors during soaking and cooking for pulses available in Canada. J. Food Sci. Technol. 54, 1014–1022 (2017).
Petitot, M., Abecassis, J. & Micard, V. Structuring of pasta components during processing: impact on starch and protein digestibility and allergenicity. Trends Food Sci. Tech. 20, 521–532 (2009).
Samadi & Yu, P. Dry and moist heating-induced changes in protein molecular structure, protein subfraction, and nutrient profiles in soybeans. J. Dairy Sci. 94, 6092–6102 (2011).
Kroghsbo, S. et al. Assessment of the sensitizing potential of processed peanut proteins in brown Norway rats: roasting does not enhance allergenicity. PLoS ONE 9, e96475 (2014).
Huttunen, H. J., Fages, C. & Rauvala, H. Receptor for advanced glycation end products (RAGE)-mediated neurite outgrowth and activation of NF-kappaB require the cytoplasmic domain of the receptor but different downstream signaling pathways. J. Biol. Chem. 274, 19919–19924 (1999).
Marciniak-Darmochwal, K. & Kostyra, H. Influence of nonenzymatic glycosylation (glycation) of pea proteins (Pisum sativum) on their susceptibility to enzymatic hydrolysis. J. Food Biochem. 33, 506521 (2009).
Bajić, B., Vučurović, D., Vasić, Đ., Jevtić-Mučibabić, R. & Dodić, S. Biotechnological production of sustainable microbial proteins from agro-industrial residues and by-products. Foods 12, 107 (2023).
Mihalache, O. A., Carbonell-Rozas, L., Sutroneo, S. & Dall’Asta, C. Multi-mycotoxin determination in plant-based meat alternatives and exposure assessment. Food Res. Int. 168, 112766 (2023).
Ong, K. J. et al. Food safety considerations and research priorities for the cultured meat and seafood industry. Compr. Rev. Food Sci. Food Saf. 20, 5421–5448 (2021).
Grandin, T. The effect of stress on livestock and meat quality prior to and during slaughter. Int. J. Study Anim. Probl. 1, 313–337 (1980).
Gouvêa, V. N., Cooke, R. F. & Marques, R. S. Impacts of stress-induced inflammation on feed intake of beef cattle. Front. Anim. Sci. 3, 962748 (2022).
Gillet, L. et al. Investigation of the susceptibility of human cell lines to Bovine Herpesvirus 4 infection: demonstration that human cells can support a nonpermissive persistent infection which protects them against tumor necrosis factor alpha-induced apoptosis. J. Virol. 78, 2336–2347 (2004).
Enache, E. et al. Heat resistance of histamine-producing bacteria in irradiated tuna loins. J. Food Prot. 76, 1608–1614 (2013).
Bodmer, S., Imark, C. & Kneubühl, M. Biogenic amines in foods: histamine and food processing. Inflamm. Res. 48, 296–300 (1999).
Singapore Food Agency. Requirements for the safety assessment of novel foods and novel food ingredients. A Singapore Government Agency Website https://www.sfa.gov.sg/docs/default-source/food-import-and-export/Requirements-on-safety-assessment-of-novel-foods_26Sep.pdf (2022).
Malerich, M. & Bryant, C. Nomenclature of cell-cultivated meat & seafood products. NPJ Sci. Food 6, 56 (2022).
Intertek. Novel food & food additive services. Intertek http://www.intertek.com/food/consulting/novel-foods (2022).
The European parliament and the Council of the European Union. Regulation (EU) 2015/2283 of the European Parliament and of the Council of 25 November 2015 on novel foods. Official Journal of the European Union https://eur-lex.europa.eu/legal-content/EN/TXT/PDF/?uri=CELEX:32015R2283 (2015).
The Office of Nutrition and Food Labeling in the Center for Food Safety and Applied Nutrition at the U.S. Food and Drug Administration. Labeling of plant-based milk alternatives and voluntary nutrient statements: guidance for industry. Food and Drug Administration https://www.fda.gov/media/165420/download (2023).
Sun, J. The regulation of “novel food” in China: the tendency of deregulation. Eur. Food Feed Law Rev. 10, 442–448 (2015).
Kwak, J. Y. et al. Regulation and current status on approval of novel food ingredients in Korea. Longdom Publishing SL https://www.longdom.org/proceedings/regulation-and-current-status-on-approval-of-novel-food-ingredients-in-korea-37327.html (2017).
Minister of Food and Drug Safety (South Korea). Administrative notice of partial revision of labeling standards for food, etc. (draft). Legislative/administrative notice. https://www.mfds.go.kr/brd/m_209/view.do?seq=43786 (2023).
Mridul, A. South Korea establishes framework for regulatory approval of cultivated meat, with applications expected soon. Cell-Based Newsalt Proteinfuture Foods. https://www.greenqueen.com.hk/south-korea-cultivated-meat-regulatory-approval-ministry/ (2024).
Minister of Public Health (Thailand). Notification of the Ministry of Public Health (No.376) B.E 2559 Re: Novel food. https://food.fda.moph.go.th/media (2016).
Appenroth, K. J. et al. Nutritional value of the duckweed species of the genus Wolffia (Lemnaceae) as human food. Front. Chem. 6, 483 (2018).
EFSA. Safety of Wolffia globosa powder as a novel food pursuant to regulation (EU) 2015/2283. EFSA J. 19, e06938 (2021).
Sela, I. et al. Wolffia globosa-Mankai plant-based protein contains bioactive vitamin B12 and is well absorbed in humans. Nutrients 12, 3067 (2020).
Adebowale, Y. A., Schwarzenbolz, U. & Henle, T. Protein isolates from Bambara groundnut (Voandzeia Subterranean L.): chemical characterization and functional properties. Int. J. Food Prop. 14, 758–775 (2011).
Diedericks, C. F., Shek, C., Jideani, V. A., Venema, P. & van der Linden, E. Physicochemical properties and gelling behaviour of Bambara groundnut protein isolates and protein-enriched fractions. Food Res. Int. 138, 109773 (2020).
Khan, M. M. H., Rafii, M. Y., Ramlee, S. I., Jusoh, M. & Al-Mamun, M. Bambara groundnut (Vigna subterranea L. Verdc): a crop for the new millennium, its genetic diversity, and improvements to mitigate future food and nutritional challenges. Sustainability 13, 5530 (2021).
Kumar, P. et al. Technological interventions in improving the functionality of proteins during processing of meat analogs. Front. Nutr. 9, 1044024 (2022).
Vatansever, S., Xu, M., Magallanes-López, A., Chen, B. & Hall, C. Supercritical carbon dioxide + ethanol extraction to improve organoleptic attributes of pea flour with applications of sensory evaluation, HS-SPME-GC, and GC-olfactory. Processes 9, 489 (2021).
Marciniak, A. & Doyen, A. High pressure for plant protein extraction. In Green Protein Processing Technologies from Plants (ed. Hernández-Álvarez, A. J., Mondor, M. & Nosworthy, M. G.) 179–192 (Springer, 2023).
Azhar, A. et al. Cell-based meat: the molecular aspect. Front. Food Sci. Technol. 3, 1126455 (2023).
Molfetta, M. et al. Protein sources alternative to meat: state of the art and involvement of fermentation. Foods 11, 2065 (2022).
Colgrave, M. L. et al. Perspectives on future protein production. J. Agric. Food Chem. 69, 15076–15083 (2021).
Ou, M. et al. Plant-based meat analogue of soy proteins by the multi-strain solid-state mixing fermentation. Food Chem. 414, 135671 (2023).
Sakai, K., Sato, Y., Okada, M. & Yamaguchi, S. Cyclodextrins produced by cyclodextrin glucanotransferase mask beany off-flavors in plant-based meat analogs. PLoS ONE 17, e0269278 (2022).
Yi, C., Li, Y., Zhu, H., Liu, Y. & Quan, K. Effect of Lactobacillus plantarum fermentation on the volatile flavors of mung beans. LWT 146, 111434 (2021).
Wang, Z. et al. Reduction of off-flavor volatile compounds in okara by fermentation with four edible fungi. LWT 155, 112941 (2022).
Yuan, F. et al. Impacts of glycation and transglutaminase-catalyzed glycosylation with glucosamine on the conformational structure and allergenicity of bovine β-lactoglobulin. Food Funct. 9, 3944–3955 (2018).
Zhu, J. et al. Effect of microbial transglutaminase cross-linking on the quality characteristics and potential allergenicity of tofu. Food Funct. 10, 5485–5497 (2019).
Ribeiro, M. et al. Efficient chemo-enzymatic gluten detoxification: reducing toxic epitopes for celiac patients improving functional properties. Sci. Rep. 5, 18041 (2015).
Brzozowski, B. Immunoreactivity of wheat proteins modified by hydrolysis and polymerisation. Eur. Food Res. Technol. 242, 1025–1040 (2016).
Muegge, B. D. et al. Diet drives convergence in gut microbiome functions across mammalian phylogeny and within humans. Science 332, 970–974 (2011).
Wu, G. D. et al. Linking long-term dietary patterns with gut microbial enterotypes. Science 334, 105–108 (2011).
Gstraunthaler, G., Lindl, T. & van der Valk, J. A plea to reduce or replace fetal bovine serum in cell culture media. Cytotechnology 65, 791–793 (2013).
Poore, J. & Nemecek, T. Reducing food’s environmental impacts through producers and consumers. Science 360, 987–992 (2018).
Miglietta, P. P., De Leo, F., Ruberti, M. & Massari, S. Mealworms for food: a water footprint perspective. Water 7, 6190–6203 (2015).
Geburt, K. et al. A Comparative analysis of plant-based milk alternatives part 2: environmental impacts. Sustainability 14, 8424 (2022).
Nikkhah, A. et al. Life cycle assessment of edible insects (Protaetia brevitarsis seulensis larvae) as a future protein and fat source. Sci. Rep. 11, 14030 (2021).
Petersen, T., Hartmann, M. & Hirsch, S. Which meat (substitute) to buy? Is front of package information reliable to identify the healthier and more natural choice? Food Qual. Prefer. 94, 104298 (2021).
Harnack, L. et al. Nutrient composition of a selection of plant-based ground beef alternative products available in the United States. J. Acad. Nutr. Diet. 121, 2401–2408 (2021).
Edge, M. S. & Garrett, J. L. The nutrition limitations of mimicking meat. Cereal Foods World 65, 1–3 (2020).
Cutroneo, S. et al. Nutritional quality of meat analogues: results from the food labelling of Italian products (FLIP) project. Front. Nutr. 9, 852831 (2022).
Dunlop, M. V. et al. Mycoprotein represents a bioavailable and insulinotropic non-animal-derived dietary protein source: a dose-response study. Br. J. Nutr. 118, 673–685 (2017).
Acknowledgements
This study was supported in part by the Bualuang ASEAN Chair Professor Fund, by the NSRF via the Program Management Unit for Human Resources & Institutional Development, Research and Innovation (grant number PMU-B: B16F640114), by the National Science, Research and Innovation Fund, Thailand Science Research and Innovation (TSRI, NRIIS project number 4709364), by Thailand Science Research and Innovation Fundamental Fund fiscal year 2024, Thammasat University, and by European Union’s Horizon Europe research and innovation programme under the Marie Skłodowska-Curie grant agreement No 101131125 - Mycobeans. Views and opinions expressed are however those of the authors only and do not necessarily reflect those of the European Union or European Research Executive Agency. Neither the European Union nor the granting authority can be held responsible for them.
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Y.M., N.K., and C.T.E. conceived the concept; Y.M., I.O.O., T.C., and N.S. performed the systematical literature search and drafted the first draft. Y.M. combined and edited the whole article with critical assistance from T.C. and N.S. N.K. and C.T.E. provided critical revision and guidance. A.P., and W.V. provided guidance. N.K., A.P., and C.T.E. retrieved financial support. All authors read and approved the final manuscript.
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C.T.E. is Editor-in-Chief and A.P. is Associate Editor for npj Science of Food. C.T.E. and A.P. were not involved in the journal’s review of, or decisions related to, this manuscript. The other authors declare no competing interests.
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Malila, Y., Owolabi, I.O., Chotanaphuti, T. et al. Current challenges of alternative proteins as future foods. npj Sci Food 8, 53 (2024). https://doi.org/10.1038/s41538-024-00291-w
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DOI: https://doi.org/10.1038/s41538-024-00291-w
