Alternatives to meat for halting the stable to table continuum – an update

Abstract

Irrefutable evidence of the adverse effects of meat consumption on health and environment, prompts an urgent need to raise awareness about moving from animal based dietary patterns to more plant based ones. Meat alternatives and meat analogues can help achieve this objective and at the same time satisfy the nutritional needs and the sensory appeal for the discerning palates of vegans, vegetarians, and meat-lovers. Recent research and development in the food industry has created meat analogues that may come very close to meats in their nutritional and sensory appeal. This paper presents a review of the available alternatives to meat with special emphasis on meat analogues mainly comprising soy, wheat gluten and mycoproteins. The paper also highlights the main processes involved in producing these meat analogues, their nutritional values, advantages, disadvantages and recognizes the scope of popularizing meat alternatives in Bahrain.

Keywords:

• Ecological footprint
• extrusion
• flexitarian
• greenhouse gases
• leghaemoglobin
• meat alternatives
• meat analogues
• mycoprotein
• plant protein
• seitan
• soy
• synthetic meat
• Textured vegetable protein
• vegetarian

1. Background

Meat is a rich source of nutrients that offers maximal sensory gratification to the human palate as compared to a variety of other food choices. Globally, demand for meat is growing unprecedented (Fiala, 2008). It has been observed that population growth coupled with economic development, lead to higher rates of meat intake globally and projections indicate a 75–80% rise in meat consumption within the next thirty years (Wellesely, Happer, & Froggatt, 2015). The adverse health and environmental consequences of this human affinity to meat is alarming and demands urgent counter strategies. Cohort studies in US and Europe as well as meta-analyses of epidemiological studies suggest that regular consumption of red meat, especially processed red meat can be linked to increased risk of mortality, colorectal cancer, type 2 diabetes and cardiovascular disease in adults. (Battaglia Richi et al., 2015). In addition, meat consumption increases the risk of zoonoses such as mad cow disease, salmonellosis, tuberculosis, influenza and parasitic infestations to name a few. (Hosie, 2018). It has been demonstrated that when animal protein, especially from processed red meat was substituted with plant protein, it lowered the mortality rate (Song et al., 2016).

Studies investigating sources of global warming invariably identify the meat industry as one of the major sources of Green House Gas (GHG) emissions. Meat consumption increases one’s ecological footprint and water footprint to a very great extent. (Hoekstra, 2009). The processes involved in the production of meat products have been shown to account for 15–24% of present-day greenhouse gas emissions (Fiala, 2008). Eco-friendly consumer behaviors are therefore essential to avert the imminent natural calamities posing threat to human existence. Healthy diets which are affordable, culturally acceptable and having a low environmental impact are referred to as “Sustainable diets” (FAO, 2010). A dietary shift towards less animal-based foods would be effective in curbing the expected growth of food-related GHG emissions. (Marco, 2016; Bajželj et al., 2014; Tilman & Clark, 2014; Hedenus, Wirsenius, & Johansson, 2014; Whitmee et al.,2015). Vegan diets can be even more beneficial in reducing the human impact on environment than cutting down on flights or using electric cars. (Poore & Nemecek, 2018); Aleksandrowicz, Green, Joy, Smith, & Haines, 2016). The introduction of plant-based meat alternatives into a “flexitarian/reducetarian” diet – basically vegetarian with occasional meat and fish, offers a great potential for preventing premature deaths as well as limiting GHG emissions (Ritchie, Reay, & Higgins, 2018).

2. What are meat alternatives?

The terms meat alternatives, meat substitutes and meat analogues, are often used interchangeably to mean a replacement to meat, yet the subtle differences between them need to be recognized. A meat alternative would be a choice of something instead of meat (it may or may not have the same qualities). For example, soya bread or spirulina tablets may be good meat alternatives due to their high protein content, but they can hardly be expected to replace meat for the more carnivorous among us. These could be further classified as meat substitutes. Meat analogues on the other hand, also known as faux meat or veggie meat or veat, include products such as Quorn burger or soy mince. These are mock meats made from non-animal protein that mimic the appearance, taste, texture and aroma of the animal product (Widjanarko, 2008) though not necessarily its nutritive value. Currently the proteins from legumes and cereals are being modified to give the texture of meats; however, it may be noted that some of these plant proteins are incomplete, i.e., they do not contain all the essential amino acids in required amounts, and hence they cannot be classified as meat substitutes. Soya, quinoa, chia and hemp are plant-based sources of complete protein that could be used in preparation of meat analogues. The main sources of plant proteins and their use in meat analogue preparation are listed in Table 1. These stand a better chance of being accepted as meat alternatives by vegetarians as well as non-vegetarians, or as meat extenders by the flexitarians. Meat extenders are non-meat products added to a meat dish in order to reduce the consumption of animal products. Flexitarians or reducetarians are those who attempt to reduce their consumption of animal products.

Table 1. Sources of plant proteins and their use in meat analogue preparation. (Adapted from Asgar et al 2010 and Nehete et al 2013).

Plant source	Protein types	Used in
Wheat	Gluten (Gliadins, and Glutenins)	Impossible burger
Filamentous fungus (Fusarium venenatum)	Mycoprotein	Quorn
Legumes	Legumin and Vicilin	Meatless uses lupine and several other brands use the legume soybean
Oil seeds	Albumins, Globulins, and Glutelins	Products made from the seed cake of oilseeds such as hemp and flax
Rice	Glutenin, globulin, albumin, prolamin	Bahama Rice Burger that uses Risofu
Pea (Pisum sativum var macrocarpon)	Pisumin, Legumin, vicilin, albumins	Burgers and other analogues made by Beyond meat Inc.

As the awareness about the environmental impact of animal farming grows, a spate of new technologies is fostering a revolution in alternate high-protein products that are totally beyond traditional agriculture, ranging from cricket flour to test-tube burgers. (Weisberg, 2016; Oswald, 2017; Tomberlin, Zheng, & van Hui, 2018; Gaydhane et al., 2018; Tao & Li, 2018). While the primary focus is meat, alternatives to dairy (animal milk and eggs) are also being explored and developed (Boyle, 2011). Alternatives to animal milk have been available for a long time due to the number of persons suffering from lactose intolerance (Sethi, Tyagi, & Anurag, 2016; Caporgno & Mathys, 2018). Of late Aquafaba, the water drained from cooked chickpeas, has become more popular with vegans as an egg replacement in certain foods such as cakes and mayonnaise, as it has similar properties (Mustafa, He, Shim, & Reaney, 2018). In fact, some companies are turning to the preparation and marketing of purely vegan food products. Coffee flour, hemp, chia, peas and flax will soon be making deeper inroads into our diet, since they have a high protein content, in fact some of them, unlike other vegetable proteins, have the added advantage of containing complete proteins. i.e., they contain all the required amino acids in sufficient amounts. (D’Ambrosio, 2015; Villines, 2018; Pihlanto, Mattila, Mäkinen, & Pajari, 2017; Weisberg, 2016; Oswald, 2017).

3. Factors affecting acceptability of meat alternatives

Any attempt at changing meat intake practices requires recognizing the multiple socio-behavioral factors linked to meat eating. (Fellet, 2015; Godfray et al., 2018). Besides the nutritional quality, availability, affordability and sensory appeal of meat alternatives are important factors that are basic to the success of strategies for meat substitution in popular diets. The sensory aspects, relevant to consumer acceptance of dietary substitutes have been well recognized. (Al-Thawadi, 2018). Appearance, texture, aroma, flavor, are important aspects to be taken care of in the creation of meat analogues. While a variety of vegetable-based substitutes or alternatives to meat are available, some of them may be more acceptable and appealing than others. In addition to the environmental and health aspects, cost is a major factor influencing dietary choices. Vegetable proteins have lower prices and a much longer shelf life than muscle proteins. The low cost of certain plant proteins, combined with the sensory appeal makes a strong case for the increasing demands for meat analogues or veggie meats. They could easily find a place on the dinner table as an economical replacement for meat among those seeking to reduce their food budgets. Although vegetable protein is lower in cost and has longer shelf life, most meat analogues are as expensive or cost more than their meat equivalent. Plausible reasons include the low demand and/or the cost of research in developing meaty taste and texture. Currently the soy protein products such as dry nuggets and granules that have been around for more than 50 years are the main low-cost analogue. It is anticipated that a paradigm shift in the dietary patterns would be followed by an accelerated demand and lowering of prices. This has been observed in the case of tissue-cultured meat discussed later in this update.

It is heartening that there is an emerging shift in dietary preferences towards veganism and vegetarianism and more importantly, recent years have seen an increase in the number of flexitarians.

While Jessica Brown states that retailers and restaurants are targeting the growing number of flexitarians, (Brown, 2018), Patrick O. Brown of “impossible foods” says that targeting the hard core, uncompromising meat-lovers is the only way to accomplish the mission of reducing global meat consumption. Veganism is on the rise prompting Silicone valley’s tech giants, such as Bill Gates, Sergey Brin, Biz Stone and Evan Williams to turn food innovators. They hope that their high-tech toolkits will help create products that meat-lovers will be happy to adopt. (Fellet, 2015). The sheer novelty and curiosity about veggie meats may tempt people to try them, and should they succeed in pleasing the palate, they would quickly and easily find a place on the meat-addicts plate. In light of the above, we have presented an inventory of those meat-mimics that can match mainly the sensory equivalence of meats, along with some information about their nutritional benefits, availability and affordability.

4. Meat analogues inventory

Currently the three most widely available meat analogues are those made from textured soya protein, mycoprotein from mushrooms and wheat gluten. Other sources such as lupines, peas & beans, rice, algae and jackfruit have also been explored, although these are still in the early stages of development. Textured vegetable proteins (TVP) are proteins extracted from vegetable products, (usually soya), that can replace meat due to the similarity in texture and nutritional value. The major part of many plant proteins such as oil-cakes are deemed waste products left behind after extracting plant oils and are used as cattle feed, but are now providing a valuable source of proteins for human consumption. An inventory of the available meat analogues along with their advantages, and disadvantages could help raise awareness; and at the same time offer a wide range of products to help shift towards a more plant-based diet.

4.1. Soy products

Texturized soya bean products are the oldest in the market dating back to the 1960s. TVP is a highly processed vegan meat substitute developed in the 1960s by food conglomerate Archer Daniels Midland. It is made by taking soy flour — a by-product of soy oil production — and removing the fat using solvents resulting in a high-protein, low-fat product. The soy flour is extruded into various shapes such as nuggets, chunks and granules. (Groves, 2018) These are usually marketed in a dry form, giving them an incredibly long shelf life. These early meat analogues had the desirable texture and high content of complete protein as well as other benefits like low saturated fat, low cost, ease of storage and long shelf life, but the odor and the taste left a lot to be desired. The good news was that they readily absorbed other flavors; so the unpleasant smell, although not completely eliminated, could be easily masked by other flavorful ingredients in the recipe.

4.1.1. Tofu & tempeh

Tofu has been included in western vegetarian diets in the past few decades, but it has been a staple in Asian cuisines for centuries. While lacking flavor on its own, it readily takes on flavors of the other ingredients in a dish. (Groves, 2018). Tofu can be made similarly to the way cheese is made from cow’s milk— soymilk is coagulated, whereupon the curds that form are pressed into blocks. It can be made using curdling agents such as calcium sulfate or magnesium chloride, however, these curdling agents affect the nutritional profile of tofu. After extraction of soymilk, the byproduct is okara (soy pulp) that is rich in protein and fiber. Tempeh is made from fermented soy where soybeans are cultured and formed into cakes. Unlike tofu, which is made from soymilk, tempeh is made using the whole soybean, so it contains more protein, fiber and vitamins than tofu. Since it is a fermented food it also contains probiotics, as well as magnesium, phosphorus and manganese which may benefit digestive health. (Groves, 2018).

4.2. Mushroom

A variety of meat analogues made from “mycoprotein” are being marketed under the brand name of “Quorn”. Quorn products are available as non-meat mincemeat, chicken cubes, steak and sausages. Although the texture and the flavor are quite similar to meat, it can still be easily identified as “not meat” to the discerning non-vegetarian. It contains the soil mold Fusarium venenatum strain PTA-2684. (Lindsay, 2018). The fermentation is done in fermentation tanks and ingredients are added to improve the nutritional value. As a non-vegan version of Quorn, the fungus culture is dried and mixed with egg albumen, to bind it together and textured into the desired forms such as mince, chicken-style pieces, steaks, patties or sausages. In the vegan version, potato protein is used as a binder instead of egg albumen.

4.3. Wheat

Meat analogues made of wheat gluten (wheat meat or seitan) are now staples in many vegetarian and vegan diets. Seitan has actually been part of the Buddhist monks’ diet for centuries. It is mainly wheat gluten, a protein formed by the combination of the wheat proteins gliadin and glutenin. Seitan is fibrous, elastic and high in protein to make an excellent meat substitute. Seitan has a mild, neutral flavor, so it can easily pick up spices and flavors of other ingredients added during the cooking process (Sedgwick, 2013).

Seitan is traditionally made at home from wheat flour. Flour and water are combined to form a stiff dough which is washed several times to remove all the starch, until only the fibrous meat-like mass of protein or gluten is left behind. Today it can be made even more easily by mixing and kneading commercially marketed vital wheat gluten powder with water to produce a dense, fibrous, chewy mass. This mass is boiled for an hour or pressure cooked to hydrate it for a better texture. Mushroom powder, soy sauce, nutritional yeast, or other marinades can be added as flavorings to the gluten powder before the addition of water, or the flavorings can be added at the boiling stage - vegetable/chicken/meat stock is used at this stage to enhance the flavor. It readily absorbs flavors and shows great potential in the preparation of meat analogues. (Hosie, 2018). To avoid boiling for an hour, a pressure cooker can be used to boil the gluten under pressure and achieve the desired texture easily. Seitan is sold as deli meats, strips and chunks in the refrigerated section of the supermarket. Figure 1 shows homemade seitan prepared with gluten powder, flavored with mushroom powder and spinach puree, colored with beetroot puree and pressure cooked in the principal author’s home kitchen.

Figure 1. Home-made seitan. Source: prepared by Manijeh Mistry (principal author)

4.4. Lupines (flowers/legumes)

Sweet lupine seeds are high in protein and therefore show promise in production of vegetarian meat. The Dutch company Meatless BV uses vegetable fibers from lupine or wheat to make their meat analogue “Meatless”. The fibers that are produced in different shapes, flavors and colors can be used to prepare meat-substitutes, or meat extenders and could even contribute to the development of “hybrid products” i.e., meat-products in which a large portion of the meat is replaced by plant protein. (Wild et al., 2014).

4.5. Rice

Bahama Rice Burger company produces rice burgers and sausages made from “Risofu”, (rice tofu). The inspiration for this product came from the Shan region of Thailand, where rice-based tofu is made. Risofu is prepared using a combination of white, brown and wild rice to provide maximum nutrients. (Villines, 2018).

4.6. Algae

Algae are protein rich, and can be grown in tanks, using just water and sunlight. Thus they offer a great potential for preparation of low-cost, vegetarian meat alternatives. Spirulina is a blue-green alga that packs 16 grams of protein per 28 grams. (Weisberg, 2016; Villines, 2018). It can simply be dried and compressed into tablets in order to supplement the diet of the economically disadvantaged. While this would satisfy the nutritional requirement, it would totally lack the sensory experience. So far, it is mainly marketed as tablets to provide a low cost protein source, but is now being developed for commercial use as a meat analogue. It is mixed with various additives like rice, oil, flavors etc., to mimic the taste and texture of meat. (Wells et al., 2017; Caporgno & Mathys, 2018). Sea grapes or marine algae of the genus Caulerpa (Caulerpa lentillifera, Caulerpa racemosa) better known as green caviar are native to Okinawa, Japan, and are now available in packed form as a delicacy. In the west, they are currently known mainly to gourmet food connoisseurs’, but they could soon become more popular as vegan caviar.

4.7. Jackfruit

Jackfruit has recently risen in popularity, largely due to its close resemblance to pulled pork. While it is a meat analogue that provides the sensory appeal, it is not a good source of protein. (Groves, 2018; Hosie, 2018). E.g. One cup of beans has 18 g protein, while 1 cup of jackfruit has 2.4 g. It is low in calories and rich in fiber and potassium.

In spite of fulfilling the nutritional requirements, most of the meat analogues are not very popular with the discerning meat-lover, as the taste is distinctly non-meat. What is it that gives meat that unique inimitable, slightly metallic flavor? An animal’s diet is responsible for the composition of its cells. Flavor and aroma arise from enzymatic breakdown of muscle cells and to a large extent from the reactions between sugars, amino acids, or fatty acids as the meat is being cooked. The main component of cells that affects flavor is myoglobin, an oxygen-carrying protein in muscle cells. Myoglobin contains heme and during cooking, it denatures to release this heme. This results in the escape of some iron that in turn catalyzes the reactions responsible for flavor and aroma. Meat changes in color during cooking. This color change is also attributed to the oxidation of iron in myoglobin which changes from a red Fe (II)–heme complex to a brown Fe(III) compound. According to Pat Brown of Impossible foods, re-creating these reactions is the key to making a convincing plant-based burger (Fellet, 2015).

4.7.1. The impossible burger

Recent research by Silicon Valley backed “Impossible Foods” has also zeroed in on heme as the main, molecule that mainly contributes to the unique meat flavor which plant products cannot seem to accurately mimic. So heme is the molecule that may play a significant role in persuading the meat-lovers to accept their mock-meats. While myoglobin is present only in animal muscle, the good news is that the root nodules of leguminous plants contain leghaemoglobin, a molecule from which the heme can be extracted. The burgers sold by Impossible Foods contain leghaemoglobin and have been created to sizzle and "bleed" juices like real beef upon grilling. It even tastes like real meat and has deceived the most ardent of the carnivorous foodies. However, if this ingredient has to be added to a growing number of meat analogues, it would need to be produced in large quantities. Extracting it from plants may not be a viable option as millions of plants would need to be ripped up to get enough heme for production. Impossible Foods has managed to produce heme in the laboratory. Heme, is mass-produced by taking the genetic code for heme production from rhizobia (bacteria) in soybean root nodules and injecting it into yeast. As the yeast grows, the gene is expressed and heme is produced; the yeast acts like a temporary heme factory. The mixture is filtered through tubes to separate the yeast and water and concentrate the heme. It is approximately a week-long process. (Robinson, 2017). Yeast can be grown quickly and easily on cheap media and this makes the temporary heme factory easier and more sustainable for bulk production. Heme is just one of many ingredients in the Impossible Burger. The foundation of the Impossible Burger is mainly textured wheat protein, a popular meat-substitute. It is cooked under pressure to imitate the feel of animal muscle. It has the potential to boost nutrition by providing more protein than beef, but eliminating the cholesterol, hormones, or antibiotics. The Impossible burger has the juiciness and texture of regular meat, and even develops a crust when cooked. It can be cooked rare, medium or well-done, to further enhance the sensory factor. The company’s Research and Development (R&D) is aiming to produce bacon, fish, chicken, milk, or cheese using their special methods. (Fellet, 2015).

The latest but by no means the last, entrants to alternate proteins, are insects and lab-grown meat. The insect-farming industry is now attracting attention from global food brands for consideration of alternate sources of protein that are sustainable for human consumption as well as for animal feed. (Plume, 2018; Tao & Li, 2018). C-Fu FOODS and One Hop Kitchen make dairy, eggs, meat, tofu, protein powders, Bolognese sauce and even ice cream from insects. (Zuppello, 2016). An optimal meat-like texture with the inclusion of 40% insect biomass has been achieved, demonstrating the potential of insect protein to generate high-protein texturized intermediates, as an alternative to fresh meat products. (Smetana, Pernutz, Toepfl, Heinz, & Van Campenhout, 2019). In 2013 the Food and Agricultural Organization (FAO) released a book entitled “Edible Insects: Future Prospects for Food and Feed Security.” It firmly endorsed, that farming insects could have huge global impact in terms of nutritional value as well as environmental benefits. (Weisberg, 2016). However, this source may not find favor with vegetarians and vegans, but if it can lure the hard-core meat lovers, it could have a favorable impact on reducing the global meat consumption.

While many scientists and food companies are focusing on meat analogues, some have been successful in growing muscle tissue in the lab to produce “cultured” or “synthetic” meat. This is termed “in vitro” meat or “clean” meat, which is closest to “the real meat” and yet does not leave an ecological footprint. While insects and lab meat cannot technically be classified as meat analogues, or meat substitutes, they offer great promise due to their sensory appeal, nutritive value, low environmental impact and ease of production. Historically, cultured meat was first stated by Churchill in 1931 who envisioned preparation of specific parts such as chicken legs or breast in the laboratory (Churchill, 1931). Jason Matheny in the early 2000s popularized the concept of cultured meat (Edelman, McFarland, Mironov, & Matheny, 2005). He created “New Harvest”, the world's first non-profit organization that was dedicated to supporting research on ‘in vitro meat. (Schonwald, 2009).

While we may think that insect meat and clean meat may be more readily accepted by the hardcore meat-lovers, but not the vegans or the vegetarians, this assumption may not be true, because even among non-vegetarians there arise various concerns on cultural, religious or health grounds. E.g. the insect source may seem repulsive to some, while others may be concerned about contracting insect-borne diseases; for Muslims the biggest concern would be whether lab-grown or cultured meat is considered ‘halal’, yet others would wonder about the health hazards of lab-grown meat, equating it to GMO. While these meats could be more rapidly mass produced than traditional meat, the R&D costs were prohibitive. However, the prices of these fake meat burgers have drastically reduced in a span of 2 years, from $325,000 per patty to $11.36 which is approximately $80 per kilogram in 2015, which is still a little dearer to the consumer as compared to the animal product. Nonetheless, the price drop is good news for commercialization of these products (Crew, 2015) while its acceptability remains a puzzle.

Our focus being meat analogues, it is worth getting an insight of the basic techniques used for their production; techniques that restructure vegetable protein akin to meat protein. Central to meat analogue preparation is the extrusion process.

The extrusion process in the preparation of meat analogues

Several processes have been developed for modifying plant foods to create meat analogues with the appearance, color, flavor, texture, and layered structure of striated muscle meat. It was mainly the research on the high moisture cooking extrusion process at the beginning of the 1990s that gave rise to new possibilities for a one-step process for texturing plant proteins to achieve the distinctive fibrous structure, moisture level, bite and mouth-feel of muscle meat (Akdogan, 1999, Wild et al., 2014). Extrusion cooking is the process by which moistened, expandable, starchy, protein-rich materials are plasticized in a tube using a combination of moisture, pressure, heat and mechanical shear. This causes temperatures within the tube to be elevated, resulting in the gelatinization of starchy components, denaturization of the proteins, stretching or reorganization of tractile components and the exothermic expansion of the extruder”. (Kearns, Rokey, & Huber, 2013). Legume protein from soy, peas or lupines can be transformed into a fibrous structure similar to meat by using the extrusion process. Addition of fat, aromas and colorings makes the texturized vegetable protein suitable for making meat analogues or extenders. After being soaked in water, a subtly laminar or fibrous structure is produced. The texture of the product should neither be too soft, nor too hard and should mimic “original” meat in a tactile or kinesthetic sense. This requires the protein to be effectively solubilized, and for the starch to be completely and consistently embedded within the protein matrix. (Coperion, 2017)

While TSP (texturized soy protein), is quite commonly found in dehydrated form as soya nuggets, it can also be found in processed, chilled or frozen, vegetarian products. Examples of processed veggie meat products include St. Ives brand of veggie dog, salami, and burgers. Advancing further, the raw materials such as shredded TVP and mycoprotein or milk protein preparations are mixed with water, a binding component and other ingredients and subsequently steamed to get fibrous elastic structure that mimic meat. (Fellet, 2015; Trinci, 1992;). Such meat analogues can be made using a variety of ingredients which, compared to TSP provide strong differentiation in shapes and flavors as well as products that fulfil attributes such as “vegan”, “organic” and “gluten-free”. Application of the extrusion process by food scientists has enabled the successful production and marketing of texturized proteins throughout the world in the last 60 years. Extrusion cooking is a continuous thermochemical process with multifunction operation like mixing, hydrating shear, homogenization, compression stream alignment, shaping, expansion and fiber formation. The extrusion cooking process, conditions such as high barrel temperature and low feed moisture, favors the Maillard reaction. This reaction is responsible for browning and flavor production by the chemical reaction between the amino groups and carbonyl groups common in foods. (Singh, Gamlath, & Wakeling, 2007).

Soy protein and wheat gluten are the main ingredients in most of the meat analogues available today. Addition of mushroom powder, yeast extract, nutritional yeast or soy sauce can provide the umami taste of glutamate, an amino acid responsible for the characteristic meat flavor. While it is relatively easy to mimic the visual similarities and flavors, the challenge lies in modifying vegetable protein to mimic the texture, juiciness and bite of meat (Fellet, 2015). European Union researchers worked together to develop a method using high moisture extrusion, to stretch globular plant proteins into stringy masses that could cling together to form fibers. High-moisture extrusion of soy powder, wheat gluten, and starch enabled the production of fibrous meat-like strips as seen in Figure 2.

Figure 2. Imitation chicken strips. (Fellet, 2015 - Image Credit: Keshun Liu, permission has been obtained from ACS, https://pubs.acs.org/doi/10.1021/acscentsci.5b00307).

Protein powder from soy or yellow pea isolates and water are poured into a machine with two long, intertwined screw like shafts passing through temperature- controlled zones. The mixture is heated and the screws mix and knead the ingredients in the chamber. The plant proteins unfold with the heat and get aligned in the direction of the flow while moving through the screw. At the end of the extruder is a cooling die that allows the mixture to solidify and develop a fibrous structure that results from the disulfide bonds formed between denatured soy proteins. The mixture is then shaped into strips, crumble or other forms.

Other methods have been employed to produce texturized proteins and formed meat analogues using spun soy protein isolates. Spun soy protein isolates can be prepared by first re-dissolving precipitated vegetable proteins and then passing them through a spinneret. They are allowed to settle into a precipitating bath. The fibers are now present as bundles that can be shaped and flavored as desired. A variety of protein sources such as glutens, albumin, isolates or extrusion-cooked vegetable proteins are usually used in the preparation of formed meat analogues. They can be shaped into patties, sheets, disks or strips. (Fellet, 2015).

Clean meat/synthetic meat production

Although synthetic meat or clean meat cannot be classified as an analogue, it is a leap towards reducing GHG and hence the basic process involved deserves a mention in our update. Mark Post, a professor at Maastricht University, created the world’s first lab-grown burger patty in 2013, thus providing proof-of-concept for in-vitro meat production (Chalmers University of Technology, 2011)- A process similar to organ regeneration in tissue culture for myocyte culture in the lab. (Datar & Betti, 2010).

Briefly, myocyte culture technique involves taking a muscle cell from a suitable animal and growing it in the lab in a suitable medium. At first, this technique yielded meat that was only produced as thin sheets, which did not give the required appearance and structure, but the taste and nutritional value was the closest to real meat. (Kadim, Mahgoub, Baqir, Faye, & Purchas, 2015) As seen in Figure 3, the introduction of scaffolding, 3-D organ printing technology and several other techniques, enabled the production of a thick well-structured meat. More R&D is required and companies are investing to develop faux meats.

Figure 3. General process for lab meat production.

Discussion

Texturized soy products were the first meat analogues due to the high content of complete protein in soybeans. The earliest soy products, in spite of their numerous advantages, were not very palatable or meat-like in taste. Over the years, soy products have improved, the unpleasant smell has been successfully eliminated and the demand has grown, particularly in places with culturally vegetarian populations of lower economic status. The increase in popularity and demand has resulted in a further reduction of cost. To quote, the cost of dry soya nuggets in Bahrain is as low as that of local vegetables in equal measure, and less than half the price of imported vegetables. It becomes even more cost-effective as it absorbs a lot of moisture and increases substantially in bulk and weight after cooking, unlike vegetables that usually reduce in volume after cooking. In fact, even some small cafeterias that cater low cost meals to laborers in Bahrain have started including soya nuggets and soya mince on their menu, often as meat extenders. There are other ready-to eat soy products on the market such as vegan sausages, deli meats and patties made by companies such as St. Ives, but these need refrigeration, have a much shorter shelf life that makes them comparatively more expensive; besides they are not widely or easily available due to their low demand. However, if awareness and demand increases, their price would reduce.

While store bought tofu is high in cost and low in fiber, preparing it domestically brings down the cost substantially. In addition, the waste material from soy-milk extraction i.e., soy pulp or okara can be converted into meat analogues which will provide high fiber and nutrients like calcium.

Quorn is rich in protein and high in fiber, which may help in maintaining a healthy gut microbiome. It is low in saturated fat and is available as mince, sausages, burgers and meat style pieces. However, some people may have severe, adverse allergic reactions to mycoproteins. Quorn is considerably more expensive than other meat analogues, especially as there are very few companies marketing mycoproteins. They are not readily available, and they are unheard of in some parts of the globe where vegetarianism is widespread. However, being one of the most palatable meat analogues, the rising awareness and shift in dietary preferences should make them more widely available at substantially lower cost. Impossible burger’s key ingredient, heme, came under criticism for not being tested enough. Nonetheless, the Food and Drug Administration has now classified “heme” as GRAS i.e., "generally recognized as safe" (Brodwin, 2018).

Seaweeds are a good source of protein, iodine and several vitamins. Some algae are easy to cultivate at low cost; hence they are potential candidates for alternate protein sources. However, certain species that produce lethal toxins should not be allowed to contaminate the algae farms. Secondly, some useful algae such as sea grapes could be invasive and damage marine ecosystems (Conrad, 2015; Tran, 2015). However, if grown in tanks under stringent controls, the presence of contaminants and toxins could be eliminated. It may be worth looking into the controlled and careful cultivation of sea grapes in tanks for use as food (caviar analogue). Drying and grinding of the high-protein waste from the farm tanks could be used for preparation of meat analogues and/or meat substitutes, and avoiding a risk to the marine ecosystems.

As with any highly processed food, commercially available meat analogues may contain substances such as MSG, fats, refined sugars, salt, preservatives or excitotoxins such as glutamate. Some soy products may contain traces of hexane used for the defatting of soya or propylene glycol (Angle-Traegner, 2018). However, it is most likely to be eliminated during processing. Jackfruit, although low in protein, has an advantage here, as it can be served with minimum processing. Also many meat analogues can be prepared in the home kitchen, where harmful chemicals could be eliminated. Another concern is that animal products are often used as natural flavoring agents or binders in meat analogues. So persons with certain food restrictions need to read their food labels before selecting a product. Vegetable foods are generally lower in terms of both quantity and quality of protein. However, simultaneous consumption of two or more incomplete complementary proteins can meet the protein requirement. For example, wheat gluten or seitan is high in protein, low in carbs and a good source of iron; yet gluten is not a complete protein. Hence if wheat gluten is mixed with pea protein and some vegetable extracts while making seitan, it would provide complete protein. The presence of fiber and lower fat content in most of these plant-based products has a particular advantage over meat. Since analogues may lack some of the vitamins present in meat, they are usually fortified with the addition of calcium, vitamin B12 and iron.

As with any allergy, people who are sensitive to soya, gluten, or mycoprotein need to take care while selecting analogues. Risofu or rice tofu is completely free of common allergens such as beans, nuts, gluten, milk and eggs, and it is also suitable for vegans. However, it is important to note that rice contains incomplete proteins, hence Risofu should be eaten in combination with complementary proteins. The phytoestrogens in soya may be linked to low sperm counts, however, there is no conclusive evidence for the same. (Hosie, 2018). On the other hand, studies have indicated the benefit of estrogens in soya, stating that they may be responsible for the hypo-cholesterolemic effect of soy. (Anderson, Johnstone, & Cook, 1995). Some research suggests that soya contains antinutrient proteins in the form of Kunitz trypsin inhibitor (KTI) and Seed lectins (Tavakolan, Alkharouf, Khan, & Natarajan, 2013) hence over-consumption of soya bean products should be avoided. However, as far as meat analogues are concerned, KTI and seed lectins don’t pose a health risk as they are denatured during the extrusion process (Delgado et al., 2012). Tempeh although high in calories, helps in lowering cholesterol, aiding bone health and may be one of the healthiest plant-based protein sources. (Hosie, 2018). Even for an omnivore, addition of some plant-based protein in the diet can be a great way to add some diversity to consumption, boosting health, as well as protecting the environment. (Hosie, 2018).

Availability and mobilization of meat analogues in local markets

In Asian markets including Bahrain supermarkets, meat analogues are hard to find, except soya nuggets, soya granules and Tofu, which have recently become more widely available. Although origins of seitan can be traced to ancient Buddhist monks, it is unheard of in most Asian markets. However, it is worth noting, that the prospect of mobilizing local sources of seitan in Bahrain appears to be promising, considering the fact that the confectionary market is plentiful with a sweet called ‘Halwa’. While halwa can be prepared from various pure starches, it is most economical to prepare it from wheat flour by eliminating the gluten in it. This gluten or seitan could be utilized in increasing the availability of gluten-based meat analogues in local markets. The incorporation of low cost meat analogues into traditional meat preparations such as kebab, tikka, harees and shilla, could provide more profit for the poor families who make traditional food as a source of income. If awareness about meat analogues could be raised by the media, especially during Ramadhan when meat consumption hits its annual high, it would go a long way in helping the dietary shift and promoting the health and well-being of the Bahraini population.

Conclusion

There is overwhelming support to the idea of shifting to mainly plant-based diets in order to improve health as well as the sustainability of food supply. It is important to note that a major paradigm shift is implicated in the adoption of meat analogues in routine meals of a meat loving population. It involves changes in shopping, cooking and eating patterns that people are habituated with since birth. The most important task is to encourage and motivate people to be adventurous in their food choices shifting from meat to meat alternatives. In the case of adoption of meat analogues in regular diets, the flexitarians will be the most willing category to accept change, while the uncompromising meat lovers will be more resistant to change. The strategies to appeal to them should include presentation of success stories, lure of lower costs, evidence of post adoption health benefits and persuasive messages about futuristic environmental benefits that they could be contributing to as responsible citizens.

Healthy Bahrain – halting stable to table

Halting stable to table mandates the following recommendations for a healthy Bahrain:

1. Review of present food-related import policies in Bahrain to consider amendments needed that will help in popularizing sustainable diets, capitalizing on the traditional food preferences of Bahrainis which are favorable for adoption of meat alternatives.

2. Innovative marketing strategies that can promote sale of meatless meat.

3. Community based research exploring:

• • Patterns of meat consumption and wastage in normal and festive seasons in Bahrain.

• • Extent of public awareness about the link between meat consumption and global warming.

• • Perceptions about meat alternatives, identifying factors that can promote or impede acceptability.

• 4. Raising public awareness about availability, use, health and environmental benefits of meat analogues via social and mass media.

Acknowledgements

We are grateful to Dr. Amal Akleh, Dean, College of Health and Sport Sciences for her constant support and encouragement. Our thanks to the University of Bahrain for affording us the opportunity to pursue research activities. Sincere thanks to Dr. Asokan.G.V., Scientific Research Committee, CHSS for his valuable guidance.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Correction Statement

This article has been republished with minor changes. These changes do not impact the academic content of the article.