While several factors have been driving interest in plant-based analogs of meat, poultry, seafood, and dairy, the phenomenal explosion in such options that the market is experiencing today came from a perfect convergence of two indispensable factors, technology and demand.

Meat and dairy analogs – even great ones – have been around for decades, although offerings were as limited as the technology. This meant only a few companies bothered to serve a very narrow consumer demand, based primarily on accepted health benefits of vegetarianism. New technology emerged gradually and trade secrets were closely guarded.

The upsurge of consumer concerns over sustainability and the environmental impact of conventional meat production, plus the trend toward healthier plant-based eating, exploded into the current hunger for animal protein analogs. Yet, without a concurrent and rapid growth in technology allowing near-perfect mimicry of the animal progenitors such analogs are modeled after, the tipping point would not have been reached.

Soy Starter

Soy is easily the best-known source of plant protein, available as protein concentrates, isolates, and texturized pieces. Soy protein has long been used in the food industry as a meat extender. It is particularly useful in meat substitutes, as the pressure from the extrusion process and disulfide bond rearrangement on a molecular level provides a fibrous, meat-like texture.

Because soy protein is one of the earliest plant proteins to achieve widespread use, especially in meat and dairy substitutes, it also is the most studied. Multiple advances have been made in its processing that build upon its already impressive functionality. Advancements also have been made in the digestibility of soy protein, with the process of phosphoesterification recently shown to improve functionality and digestibility of soy protein as well as peanut proteins.

Proof of how hot the plant-based meat trend is that even meat companies have joined in, such as JBS USA‘s Planterra Foods, Inc. and its OZO product line. PHOTO COURTESY OF: Planterra Foods, Inc. (www.ozofoods.com)

Despite soy’s advantages, there are some challenges associated with its use in food products. Some soy products can have undesirable beany flavors and odors. And, while soy protein still is the leading plant protein in food products, it also is one of the eight major food allergens. Moreover, it is commonly derived from genetically modified sources.

Another difficulty in working with soy proteins is the presence of interfering ingredients in the production of protein isolates. These can alter the conformation of the proteins, either enhancing or decreasing their functional power. For these reasons, other plant protein sources have experienced a rapid increase in popularity.

New Kids

Protein ingredients derived from pea, rice, chickpea, chia, and quinoa are trending sources that offer a significant level of functionality. Products using these sources have been adding new dimensions to a market traditionally dominated by soy. Their functionality is dependent upon a number of factors: structure and size of protein molecules; the pH, ionic strength, and processing conditions of food products; and the isolation process of the protein itself.

Pea protein is an excellent source of plant-based nutrition, is not a major allergen, and is suitable for gluten-free products. Native pea protein itself has poor functionality, but extensive research has contributed to refinements of the extraction process that have improved its functionality.

Such methods include Maillard reactions between pea protein (whole or hydrolysates) with polysaccharides such as gum Arabic, which recently was shown to increase emulsion stability. Shearing also can be implemented to improve the protein’s heat stability and solubility. Spray drying techniques with maltodextrin and gum Arabic also can help mask or improve beany flavors of pea protein powders.

Pea protein has been blended with rice protein and then treated with direct steam injection, which improved solubility, emulsifying activity, foam stability, and oil-holding capacity. Blending these two proteins provides higher amounts of essential amino acids than either source alone, as legumes are traditionally deficient in methionine, while grains are commonly low in lysine.

Pea protein is suitable for nutritional beverages and shakes and can be used alone or in a blend with other proteins, such as soy, in meat and cheese substitutes. Like other ingredients from soy and legumes, pea protein can impart beany flavors and odors. However, newer formulations of pea protein have diminished this quality, as well as a chalky mouthfeel that had been another challenge to use of pea protein.

Mushroom for Improvement

Filamentous fungi, while not exactly plants, present an excellent source of non-animal, renewable protein. Several fungal species can be utilized to cultivate mycoprotein, and they typically retain their fiber content. Fusarium venenatum has long been used in the production of meat substitutes but as yet has not been widely utilized outside this market category.

Mycoprotein from F. venenatum is touted for positive health benefits, including satiety, improved glycemic response, stimulation of insulin products, maintenance of healthy cholesterol levels, and stimulation of muscle protein synthesis. Other fungi, such as Pleurotus albidus and Agaricus bisporus, recently have been researched for their mycoprotein cultivation potential.

Although fungal protein can be used on its own, fungi also have potential to enhance the protein content of byproducts from production of other protein ingredients. A recent study suggested edible filamentous fungi could be used to obtain vegan protein from byproducts of pea protein isolation.

Isolated cases of allergic reactions to mycoprotein from F. venenatum have been reported, but they remain few in number. However, some species of F. venenatum are capable of producing mycotoxins, requiring processors to seek the ingredient from only reputable suppliers with comprehensive knowledge of working with the source. Mycoprotein from F. venenatum has been sold in meat analog products in the UK and US for the past few decades.

Dave Anderson, former executive chef of Beyond Meat Co. where he formulated the Beyond Burger, is now the executive chef at Outstanding Foods, Inc. where he put mushroom protein and a combination of pea protein and rice to create PigOut Chips and PigOut Pigless Rinds. Unlike the deep-fried pork skin-derived versions, Anderson had to balance starch and protein to obtain the right texture.

“The biggest texture challenge came with the decision to make the PigOut rinds a high-protein snack food,” says Anderson. “Porkless rinds are an extruded puff product, and starch is what causes these types of products to puff. When protein is added to the mix, it actually inhibits the puffing of the product. As an example of the difference, a product like cheese puffs has 0.8 grams protein per ounce, while the Pigless Pork Rinds have seven grams of protein per ounce. In order to solve the problem, we tested many different types of flours and proteins in multiple combinations until we came up with a blend that resembled a pork rind. From there, we fine-tuned it by testing different aspects of the extrusion process until we dialed in the product focusing on shape, appearance, mouthfeel, texture, density, while working on seasoning blends that would give us the proper flavor profile.”

Seeds of Change

Seeds from quinoa, a plant classified as a pseudo-cereal, present a good source of protein in addition to dietary fiber, the tocopherol form of vitamin E, and certain phenolic compounds. The essential amino acid content in quinoa is higher than that of true grains and legumes. 

As noted above, this can address the fact that these traditionally are deficient in lysine and methionine, respectively.

Quinoa is gluten-free and non-allergenic. Because this protein source is eliciting greater interest, research has begun to improve protein extraction methods. A recent study showed finer particle size improves the dietary fiber content, protein content, and antioxidant properties of quinoa flour. Another study suggested sonification could be used to improve the functionality of quinoa protein isolate. The addition of other ingredients, such as the natural seaweed extract carrageenan, also influences quinoa protein’s solubility and gelation.

Quinoa proteins exhibit an ability to contribute to biochemical functions. They’ve demonstrated antibacterial, antioxidant, and antihypertensive activity. Preliminary research on quinoa suggests it also helps reduce cholesterol levels and prevents hepatic steatosis in obese mice. While quinoa flour is more widely available, quinoa protein ingredients remain new. Yet, they present a novel source of protein for meat and dairy substitutes, especially beverages.

Chia seeds have recently been recognized as commercial sources of plant protein, and they offer yet another option for gluten-free food formulations. Similar to quinoa protein, chia seed peptides have potential health benefits, such as antioxidant and anti-inflammatory capacity.

Preliminary research from animal studies revealed that chia seeds could help reduce cholesterol and improve the health of patients with non-alcoholic fatty liver disease or non-alcoholic steatohepatitis. Another study demonstrated that chia protein hydrolysates inhibit angiotensin- converting enzyme (ACE), thereby lowering blood pressure.

Like legumes, mushrooms, and other pseudo-cereal seeds, chia is gluten-free. It also is non-GMO. Being a meal byproduct from chia seed oil production, it is an inexpensive source of plant protein. As with quinoa, flour made from chia is prevalent, but chia protein ingredients are not yet widely available. Even so, chia protein usage is gradually expanding. It has proven to be an excellent protein source for beverages.

Fluid Assets

Plant-based milks have been used in cultures around the world for centuries. While soy milk, coconut milk, and rice milk were once the most common milk alternatives available, several nuts and grains have flooded the market with milk analogs. Almond and rice milks certainly are the leaders, but milks made from cashew, walnut, hazelnut, macadamia, sunflower, and spelt are now available as well.

Plant-based milk alternatives are projected to reach sales of US$26B globally by 2023. Nuts and grains are used in other traditional dairy products, such as cultured yogurt alternatives, non-dairy creamer made from oats, and imitation cheese made from almonds, rice, soy, and cashews. Among the newest cow milk alternatives, tiger nut milk (also known as horchata de chufa) already is popular in parts of Spain and Nigeria.

While the amino acid profile of plant proteins is not the same as that of dairy proteins and often comes with unsavory organoleptic attributes, several technological advances allow the use of plant proteins in beverage products. Among these technological tweaks is fermentation, which can improve the solubility, amino acid availability, and sensory attributes of plant-based milks and even enhance accessibility of bioactive components. It is important to note that plant-based alternatives to cow’s milk do not provide the same vitamin and mineral content.

A Growing Future

Hemp seed is one potential source of novel protein ingredients. Hydrolysates from protein isolates obtained from defatted hemp seed meal have shown promising ACE inhibition potential, similar to chia. Additionally, hemp protein is non-allergenic. Hemp can be used to make plant-based milk, and a recent study from Sweden touted successful results using hemp protein concentrate alongside soy in extruded meat analogs.

Lupin and rapeseed also are gaining attention as contending sources of protein. Protein from rapeseed press cake is similar in essential amino acid content to proteins from egg and bovine milk. A recent study also suggested chickpea protein, already moving up the ladder of common proteins in formulations, could be an excellent carrier of iron fortification to aid iron-deficient populations.

As trends in plant-based foods and sustainability continue to surge and more consumers explore vegetarian/vegan/flexitarian diets, it is certain that new sources of protein will be studied and utilized. With careful ingredient consideration, plant-based meat substitutes provide an opportunity to drive higher intake of whole grains and legumes.