In total, 1036 patent applications were found from January 2015 to June 2020 in the IPC A23J1/14 subgroup. The final sample counted on 113 patents after screening and eligibility criteria application. By comparing the number of plant-based beverage applications in the last 5 years, it was possible seeing an increase in this number back in 2019: 44 patent applications (Fig. 3). Noteworthy, 26 patents were applied up to June 2019, and this finding is indicative of upward tendency estimated to the number of applications in the following years. Such an estimate can be confirmed by both the current plant-based beverage consumption trend1 and populations’ increased interest in protein-rich products9.
Patents were divided into three different groups, namely: “seeds and nuts”, “legumes and pulses”, and “other mixes”, since A23J1/14 subgroup is related to leguminous, vegetable seeds, press-cake, or oil-bearing seeds (Fig. 4). Based on the results, most patents are related to legumes and pulses using (45%), followed by seeds and nuts (36%), other mixes (18%), and patents that did not specify their raw materials (1%).
Most patents (n = 40) mentioned their applicability to protein-rich beverage production. This finding was expected due to the current demand for this category of product9 (Fig. 5). Milk analog (n = 27) and fermented beverage/yogurt analog (n = 25) come right in sequence, and it corroborated consumers’ increased interest in alternatives to dairy products1. Sports drink (n = 25), carbonated beverage (n = 22), juice (n = 17), and acid beverage (n = 11) were also often addressed in patents, and this finding meets the current need of using plant proteins at different pH ranges without compromising the features of final products.
Figure 6 shows the preferable raw materials for patent applicants. It is important to point out that the sum of recorded results will be higher than the total number of patents selected for the current study if one takes into consideration that some patents used more than one raw material on its applicability. The most preferable raw materials chosen by patents applicants were pea, rapeseed, and bean.
Seeds and nuts
Seeds are of great economic and biological importance if one takes into account that they have a high oil and protein content, and large starch reserves. Nuts from trees are recommended as part of a healthy diet given their protein, phytochemicals, micronutrients, and unsaturated fat content14. Seeds and nuts can be the raw material for oil production, which is often extracted by cold pressing—this process generates a by-product known as “press-cake”; or it can also be extracted with organic solvents—in this case, the residue is called “meal”26. The global 2018/2019 oilseed production reached 600.47 million metric tons27, hence huge amounts of oil extraction by-products are available. Although press-cakes and meals are often discarded as waste or used as components for feed supplementation, they are good protein, fiber, and bioactive compound sources26,28. Moreover, because of the increasing demand of protein products, such waste types are a potential alternative source for protein extraction5. However, the oil extraction procedure often decreases protein solubility29 and it compromises its use in beverages. Thus, many of the herein-reviewed patents were related to methods applied to increase or preserve the solubility of proteins extracted from cakes and meals. Furthermore, depending on the raw materials, meals and press-cake often possess undesirable amounts of compounds that decrease protein digestibility, such as fibers and antinutritional factors5—such a matter is constantly discussed in most patents as well. Moreover, the preferable protein extraction methods were related to the protein precipitation using an alkaline, acid, or salted solution, followed by a specific filtration and drying technique (Table 1).
Based on the results, rapeseed was the most used seed, since it was the preferable raw material in 25 patents (Table 1). Rapeseed ranks second position of the major oilseed cultivated worldwide, it just loses its position to soybean30. Rapeseed and “canola” are the common names given to species Brassica napus L., Brassica rapa L., and Brassica juncea L; however, the name “canola” only refers to rapeseed varieties presenting less than 2% erucic acid and meal accounting for less than 30 μmol/g total glucosinolates. The crude protein in rapeseed meals ranges from 35 to 40%. At least 40 different protein fractions can be found in this total, but cruciferin, napin, and oleosin are the most investigated ones5. Cruciferin and napin are the main storage proteins, they account for 60 and 20% of the protein content in rapeseeds, respectively26. Oleosin presents structural proteins associated with oil components31. Although rapeseed has lower sulfur-amino acid levels5, canola meal has better amino acid profile than soybean. Nevertheless, canola proteins present many antinutritional factors, as among them glucosinolates, phenolics, phytates, as well as a large amount of fibers capable of compromising digestibility, color, taste, and physicochemical properties29. This finding explains some authors’ interest in patenting inventions that can solve these problem. Patents WO2019110556 (A1) and EP3481220 (A1) explain how to isolate inherently sweet rapeseed proteins presenting low content of antinutritional factors and high solubility, which can be used to reduce the amount of sucrose in beverages, and simultaneously increase protein content in the product. Likewise, BRPI0917295 (A2) provides rapeseed protein isolate that is soluble and stable not only in acid pH but also at higher temperatures. At the moment, Burcon® is the only manufacturer of high-purity canola protein in the world32,33, despite the potential of this raw material.
Hemp (Cannabis sativa L.) was the preferable raw material in 11 patents (Table 1). It is mainly cultivated for the industrial use of its seeds, fibers, oil, and meal34. At the moment, hemp is at the mainstream, since it is a sustainable crop that does not require fertilizers, herbicides, and pesticides35. Hemp can be legally cultivated for industrial purposes in most countries worldwide, when it has up to 0.3% of its main psychoactive compound: delta-9-tetrahydrocannabinol (THC)26. Hemp seeds are rich in phytosterols (ω-3 and ω-6) and have ~25% of proteins in its dry weight35. Approximately 65% of the total hemp protein comprises a single globular storage protein: edestin; on the other hand, the albumin fraction consists of 25% of storage proteins26. Although it has low lysine content15, hempseed protein contains all the essential amino acids and accounts for low amount of antinutritional factors, such as trypsin inhibitor; therefore, it presents high-degree digestibility35. Hempseed protein can be appropriate for athletes and infants, for example, given their quality. Patent BR112015001964 (A2) provides a hempseed protein that is completely soluble in acid beverages (lower than 4.4 pH), without the need of stabilizers or additives. Thus, it can be used for protein fortification in soft and sports drinks, as well as in other aqueous systems. Similarly, CN110150391 (A) disclosed a canned beverage for athletes made with hempseed albumins, which is even better absorbed by the organism than the whole hempseed protein. US2015079235 (A1) proposed hempseed protein using as the main ingredient in an alternative infant formula, which can be either powdered or liquid. Currently, Axiom Foods® and Good Hemp®, which offer products with 58 and 85% purity, respectively, are among the hempseed protein suppliers in the world36,37. Also, Manitoba Harvest® and LeanHemp® are brands focusing on the hempseed protein supplement segment38,39.
Ten patents used Sunflower (Helianthus annuus L) as preferable raw material (Table 1). This species is one of the most cultivated oilseed crops40; its seed meal can reach 40% protein content when it is mechanically extracted, and 50% protein content when the oil is extracted with organic solvents5. Approximately 85% of the total protein content in sunflower seeds is found in the form of storage proteins (11S helianthinin globulin and 2S albumins)26. Globulin content varies from 40 to 90%, whereas albumin rate ranges from 10 to 30% of the total protein found in seeds. It is possible observing differences in the ratio of these protein fractions since three different sunflower seed types are majorly cultivated—they are used for oil production, human and pet consumption, and ornamentation5. Despite its low lysine content, sunflower meal remains a good protein source, given its high digestibility and smaller number of antinutritional compounds41. Although sunflower seed proteins have low functionality, such a feature is closely linked to denaturation caused by heating at oil extraction, rather than to native proteins themselves. Moreover, phenolic compounds found in sunflower seeds, such as chlorogenic acid, can crosslink with proteins and change its color, functionality, and bioavailability. However, chlorogenic acid is also beneficial for human health40 and can be desirable when it is properly extracted from sunflower seed meal. Patent CN109354574 (A) improved a method by using supercritical carbon dioxide extraction to prepare chlorogenic acid and protein powder from sunflower seeds, in separate. This powder is an interesting raw material for making artificial milk and beverages due to its soft flavor. Similarly, FI128029 (B) addresses a sunflower seed protein with enhanced solubility and low phytate content. Its powder is a suitable ingredient for dairy alternatives. Following functionality improvements, BR112018070543 (A2) used enzymatic treatment, heating, fermentation, and pressure treatment to increase the techno-functional and organoleptic properties of sunflower seed protein, which is useful as a beverages’ supplement. Presently, Biotechnologies® is the only world sunflower seed protein producer whose product has more than 80% purity42; However, it is possible finding other suppliers whose products reach about 50% protein content, among them one finds Austrade Inc® and ETChem[®43,44.
Based on the results, cottonseed was the preferable raw material in seven patents (Table 1). Fiber is the most common product made out of cotton; however, cottonseed has great potential as protein source, for both animal and human consumption45. Cottonseed meal has ~30 to 50% total protein46. Arginine has the highest content (22–34%) of essential amino acids, whereas cysteine accounts for the lowest one (1–2%)47. Cottonseed meal is a good protein source for ruminants, but it is not appropriate without treatment for monogastric animals, including humans, who do not tolerate high fiber contents and antinutritive compounds, such as gossypol, phytin, and cyclopropane fatty acids46. In total, 80% of defatted cottonseed is used as substrate for edible mushroom crops or as fertilizer, but only 5 to 10% of it is used for animal feeding purposes, a fact that causes huge protein waste48. The appropriate extraction of these proteins from the meal is a feasible option to solve this problem. Patents HUE033952 (T2) and PL2498620 (T3) disclosed enhanced methods to produce high-quality protein concentrates and isolates from oilseed meals, including cottonseed, which has incredibly low fiber content and antinutritional factors. These concentrates and isolates are useful as powdered milk analog or to increase protein content of juices, soft drinks, sports drinks, and beverages in general. RU2018129466 (A) disclosed a method to extract cottonseed proteins that can fortify beverages as well. When it is compared to other patents, it also has the advantage of not presenting beany or grassy flavor notes. Nevertheless, so far, cottonseed protein suppliers in the market only provide to animal feeding, they still do not focus on human nutrition.
Legumes and pulses
Legumes are the most consumed staple food after cereals, since they are a low-priced source of nutrients, mainly of proteins; therefore, they are seen as “meat for poor men”14,15. In botanical terms, legumes belong to the family Leguminosae, which also comprises pulses. All pulses are legumes, although not all legumes are pulses. Based on the Food and Agriculture Organization definition, pulses are only dried edible leguminous presenting low oil content. Consequently, legumes harvested in green forms, such as green beans and green peas, are not included in this group. Furthermore, soybeans and peanuts, which are oil-rich, are also excluded from it. Lastly, crops used for sowing purposes, such as alfalfa and clover, are not pulses49. Pulses are good energy, fiber, vitamin, mineral, and bioactive compound sources, and besides, ~30% of pulses’ dry bases are proteins50. In addition to their nutritional importance, pulses have the good nitrogen-fixing capacity and are beneficial to soil fertility and the environment51. Some native pulses and legumes’ proteins are promising to the beverage industry due to their functional features, such as solubility, emulsifying, and foaming proprieties50. However, depending on the species and on the protein extraction method, beverages made with these proteins also show beany flavor, bitter taste, or sandy mouthfeel4,14,15 —these factors limit their acceptance by consumers. Another disadvantage of these proteins lies in the fact that different procedures must be followed in order to reduce antinutritional factors and nonprotein compounds from pulses and legumes. Although, isolate proteins extracted from legumes and pulses remain in the mainstream of researchers and patent applicants as they are an economical, ecological, nutritive, and gluten-free raw material used to enrich products50. Enzymolysis and protein precipitation using an alkaline, acid, or salted solution were the preferable protein extraction methods applied, commonly followed by a specific filtration and drying technique (Table 2).
Pea was the most used raw material in the herein assessed patents, it was the preferable raw material in 43 patents (Table 2). Pea is an ancient crop widely grown in different countries50. At the moment, pea stands out for its properties similar to those of soybean protein; therefore, it presents great potential to replace this protein, since soybean is often associated as allergenic13. Emulsification, foaming, and gelling are some of these properties, for instance14. Pea has 23 to 31% total protein, and 50 to 85% are globulins (legumin, vicilin, and convicilin), while 15 to 25% are albumins50. Arginine, phenylalanine, leucine, and isoleucine are among the essential amino acids commonly found in the globulin proteins, whereas tryptophan, lysine, threonine, cysteine, and methionine are found in the albumin ones52. Overall, the amino acid profile is well-balanced and the high lysine content is notable13. Even so, the bitter taste intrinsic to pea flour produced through dry milling can be transferred to final products. Patent CA3067593 (A1) disclosed methods to produce pea flour, concentrate or isolate with low nonvolatile flavor compound contents, specifically bound saponin, in order to solve this problem. This process consists of steam cooking and drying a raw pea slurry to produce a bitterless flour that can be used in beverages. Similarly, FR3070831 (A1) used sodium citrate and heating to partially or fully reduce the bitterness of pea protein compositions. Fermentation can also improve flavor; therefore, yogurt-like products are a good option to be made of pea protein, as proposed by CN109566747 (A). Pea protein has been consolidated in the market by world suppliers such as Roquette®, Burcon®, Axiom Foods®, AMCO Proteins®, Ingredion®, Cargill®, and Farbest[®53,54,55,56,57,58,59. Pea protein milk and yogurt are already available and provided by Ripple® and Siggi’s®, respectively60,61.
Based on the results, bean was the preferable raw material in 21 patents (Table 2). Common beans belonging to the family Leguminosae and to genus Phaseolus account for one-third of global pulses production62. There are more than 14,000 known different common bean cultivars. Peculiarities of local culture, agriculture, and history influence the mostly consumed beans. Variations on beans’ size, shape, and colors can occur, as well as on their composition and physicochemical features, but these differences tend to be nonsignificant63. Overall, dry beans are an important source of proteins—its protein rate ranges from 16 to 33%50. Albumins account for up to 10–30% of total protein content on dry weight basis, whereas globulins account for 45–70% of it52. Phaseolin and lectin are other important protein fractions found in beans50. Although the protein content in beans is significant, it shows some drawbacks, since beans have methionine as limiting amino acid and antinutritional factors are observed in them62. These factors can be removed from pulses through a simple fermentation process; consequently, it increases the quality of pulses’ proteins15. Patent JPWO2014156549 (A1) disclosed methods to produce a gel by adding alkali metal ions to mung bean protein and by fermenting it. The produced composition can be used as yogurt analog. Similarly, CN106261782 (A) used biological mung bean fermentation to separate protein, starch, fiber, and slurry, and to provide different products, such as instant tablet beverage and fermented drink. Once more, to reduce antinutritional factors, KR20190087654 (A) developed a bean protein presenting low phytic acid content by using calcium salt to precipitate it. At the moment, It is possible finding 80% purity mung bean and fava bean protein suppliers, as among them one finds ETProtein® and Atura®, respectively64,65. The brand Green Boy® also offers powdered proteins extracted from these same bean species66,67. Nancy’s® produces yogurts with different flavors, all made of fava bean protein68.
In total, 18 patents were related to peanut’s use as preferable raw material (Table 2). Peanut accounts for 11% of the global protein supply69; it has been gaining more popularity due to its resistance to climate changes8, as well as because it is a cheap source of high-quality protein. Deffated meal, which is a by-product by the peanut industry, has ~50–55% protein and balanced amino acid profile70; therefore, it can be easily used as raw material to produce protein isolates71. Peanut proteins are often classified as albumins and globulins. Arachin and conarachin are the main globulins, and both of them are rich in lysine, tryptophan, tyrosine, and phenylalanine69. Peanut protein is often nutritionally comparable to animal protein72, mainly after fermentation, since this process increases its l-lysine, l-methionine, and l-tryptophan contents1. However, its allergenicity69 and poor functional proprieties hamper peanut protein use by the food industry70. Different treatments, such as chemical, physical, or enzymatic methods, have been applied to expand peanut protein functionality. Patent CN106260496 (A) disclosed an improved ultrasonic treatment applicable to peanut protein that provides better solubility, higher yield, and efficiency, as well as environmental protection, when compared to the state of the art. FR3072002 (A1) addresses a stable gel that can be produced by improving peanut protein solubility followed by adding transglutaminase to it. This gel is highly useful to produce yogurts. According to CN106367196 (A), it is possible obtain peanut protein that presents stability in beverages by preventing its denaturation during the extraction process. High-purity peanut protein isolates or concentrates are not in the market yet; however, deffated peanut powder is already provided by ETChem® and Peanut Butter & Co®, for example73,74.
Based on the results, chickpea was the preferable raw material in 12 patents (Table 2). It is the second mostly produced legume worldwide and its protein amount ranges from 15 to 30%. Globulins (53 to 60%) and glutelins (19 to 25%) are the main protein fractions in chickpea, but albumins (8 to 12%), and prolamins (3 to 7%) are also relevant in it50. Although chickpea lacks sulfured amino acids52, it has low content of antinutritional factors and, consequently, high bioavailability of other essential amino acids14. Blend chickpea with other pulses that do not lack sulfured amino acids is an interesting solution to its limiting amino acids issue, so the quality of the protein in the final product increases significantly. Patent CA2982280 (A1) provided a method to produce an alternative to milk by using chickpea and/or pea protein as main ingredients. Moreover, the disclosed product has a smooth mouthfeel and does not necessarily need gum, emulsifier, or starch to be added to the formulation. On the other hand, EP3586644 (A1) and WO2020061698 (A1) focused on the production of pulse proteins, including chickpea. These proteins are stable both in hot and acid aqueous environments. Among chickpea proteins available in the market, finds the ones by Innovopro® and Atura®, which sell products with 70 and 80% protein contents, respectively75,76. The brand Green Boy® also has chickpea and other different plant-based proteins in its portfolio.
The group “other mixes” regards patents that used either seeds, nuts, legumes, pulses, cereals, seaweeds, fungus, or combinations of these elements. These combinations include blended products to reach a better amino acid score and to optimize the functional and sensorial features of final product. Such an outcome can be obtained through the interaction of proteins from different plant sources (Table 3).
FR3085826 (A3) disclosed a powder ready to be reconstituted in water or plant-based milk. This process uses proteins from peas, rice, oats, or from their mixes. Similarly, EP3429366 (A1) divulges a replacement for dairy milk, which is made of peanut protein—but it can also be made of cashew nut, almond, pea, oat, wheat, quinoa, or of combinations of these elements.
In regard to functional improvements, CN111227101 (A) provided an instant powdered beverage that can be composed of pea and rice proteins, which shows excellent solubility in hot water (≥85 °C). JPWO2013027813 (A1) presented a beer-like product with increased foam stability that was produced with protease, transglutaminase, and with one or more proteins from wheat, barley, corn, pea, or rice.
Focusing on sensorial aspects, WO2019228957 (A1) described a method to mask undesirable notes from beverages made of pea, wheat, or oat protein when ethyl cyclohexanoate was used as additive. EP3634146 (A1) suggested the application of ultrasound and membrane filtration processes in proteins from legumes, seeds, seaweeds, or fungus to obtain a clean taste and neutral color product that can be used to enrich a wide range of beverages.
A huge variety of blended products has been introduced in the market. The supplier Burcon® developed a combination of pea and canola proteins, which is nutritionally and functionally better than when these proteins are used separated. The brand Orgain® offers a blend of deffated peanut powder, pea protein, pumpkin seed protein, and almond protein77, while Manitoba Harvest® commercializes a mix of pea and hemp proteins, which is ideal to be added to smoothies or nondairy milks78.