**Abstract**

Cowpea (*Vigna unguiculata*) is among the pulse's species of greatest economic and social importance. This legume is strategic for the food security and health of millions of people in the world. Cowpea is rich in nutraceuticals compounds such as dietary fibre, antioxidants and polyunsaturated fatty acids and polyphenols, whose health benefits and use in the food industry have been extensively studied. However, research on the identification of functional proteins from cowpea, their metabolic functions and applications in the food, health and other industries are still scarce. In this chapter, a critical review of the most recent and important research about functional cowpea proteins. We objective was identify and systematize information about the nature and functions of these proteins, as well as their use and applications in food, health and other industries. Cowpea seed proteins are highly versatile and offer direct health benefits such as reducing the incidence of cardiovascular disease and some types of cancer. The proteins of cowpea are also used in material science for the development of new technologies such as development of special fabrics for protection against ultraviolet rays and microencapsulation of ascorbic acid.

**Keywords:** pulse, essential amino acids, globulins, nutraceuticals, food industry, *Vigna unguiculata*

## **1. Introduction**

The rapid increase in the cost of animal-based protein foods has increased interest in plant protein, especially from the before underutilized crops [1, 2].

The consumption of pulses (e.g., lentil, common bean, chickpea, and dry pea) generates positives impacts human and environmental health impacts, making them an ideal food for wise and conscientious global citizens [3, 4].

In fact, 2016 was declared by FAO as the International Year of Pulses, intending to heighten public awareness on the nutritional and health benefits of pulses, their biodiversity and climate changes adaptation, included in a sustainable food

production strategy designed to achieve food security and adequate nutrition [5]. In addition, pulses are a fordable and shelf-stable [4]. The American Pulse Association calls pulses the world's most versatile superfood [6].

Protein energy malnutrition (PEM) is one of the most severe public health problems in many developing countries [7]. Particularly, child malnutrition was associated with 54% of deaths in children in developing countries [8].

Cowpea (*Vigna unguiculata* L. Walp.) (2n = 2x = 22) [9] provides food for millions of people and is important in alleviating protein-calorie malnutrition [10]. Also is a good source of essential amino acids (e. g. Lys, His) and the aromatic AA [10, 11]. Because of its high crude protein content and a good balance of EAA, cowpea is usually considered as a complete food [12]. Cowpeas are also good sources of fibre, iron, zinc, and contain substantial amounts of bioactive compounds [13].

Cowpea has been promoted as a high-quality protein constituent of the daily diet among economically depressed communities in developing countries, with the aim of reducing the high prevalence of protein and energy malnutrition [14, 15]. Nutritionally, cowpea grain is the same as other pulses, with a relatively low-fat content and high total protein concentration [10].

Cowpea is a major alternative for the production of vegetable protein to be a culture of easy cultivation, low demand for soil fertility and adaptability and stability in all continents [16]. Cowpea ability to growth in low fertility and to subsist in soils where drought is a major constraint due to low and irregular rainfall confers advantages over other legume crops [17, 18].

Cowpea are also used as green manure, employed in a rotary schemewith other annual crops or in fruit plantations to increase or sustain soil fertility [19]. Dried cowpea seeds can be used for making cake or the seeds could be boiled, mixed with sauce or stew and consumed directly [20]. In addition to its great economic, social and environmental importance, cowpea is a crop with great industrial potential [21].

In the food industry, cowpea seeds is used in the production of canned and preserved foods, and in the production of isolated proteins with various applications (e.g. production or additives in flour, supplements for athletes and functional foods) [15, 19, 21–23]. However, a certain "underutilisation" of cowpea in food applications has been attributed to its beany flavour, presence of antinutrients and the hard-to-cook defect that prolongs cooking time [24].

The identification of the cowpea functional proteins and the investigation of the mode of action and application of these proteins aim to systematize information and contribute to the development of cowpea cultivation and the industrialization of this still underutilized culture, considering its great potential and studies already carried out in various areas of science.

#### **2. Cowpea functional proteins**

Vegetable proteins are presented as functional, as they provide health benefits, in addition to the essential nutrient's characteristic of the species. Functional properties of proteins are important in food processing and food product formulation. Some of these properties are water/oil binding, emulsification, foam capacity and gelation. These properties depend on characteristics of proteins such as molecular weight, amino acid composition, net charge and surface hydrophobicity [22, 25, 26].

**53**

**Figure 1.**

*values found in the literature. Adapted from [10].*

*Health Benefits and Industrial Applications of Functional Cowpea Seed Proteins*

protein content of cowpea differs along with the variety [12].

in seeds with high proline and glutamine content [41].

of proteins (23–32%) and carbohydrates (50–60%), fibers, vitamins and nutrients,

Nutritional values and protein quality dependent on its amino acid composition, susceptibility to hydrolysis during digestion, purity and applied processing processing effects, such as heat treatments [29]. The nutritional and functional properties of pulses proteins depend on the nature of soluble fractions [12, 30]. Generally the

Cowpea has high protein and carbohydrate contents with a relatively fat-low content and a complementary amino acid pattern to that of cereal grains make cowpea an important nutritional food in the human diet [10]. Cowpea protein is rich in essential amino acids, particularly lysine, histidine and aromatic amino acids [31]. However, it is deficient in methionine and cysteine compared to animal proteins [32]. **Figure 1** shows the amino acid profile (essential amino acid) of

The amino acid profile makes cowpea protein unique and of unquestionable quality [10]. The functional attributes of proteins like gelation, foaming, emulsification, thickening also drive the incorporation of isolated proteins in various foods like mayonnaise, baked foods and beverages [33]. The manner of converting the isolated proteins into powders also determines their functional

In cowpea, protein types comprise globulins, albumins, glutelins and prolamins [12, 35]. Albumins and globulins are considered to represent the major storage proteins in cowpea [36]. Globulins represent most cowpea seed proteins and constitute over 51% of the total seed protein, while albumins approximately

Glutelins have poor lysine content in cowpea [12]. Albumins has functional role in seeds as enzymatic and metabolic proteins (i.e. lipoxygenase, protease inhibitors and lectins) [38, 39]. Globulins has an important role as storage proteins and were mostly digested by proteases [38–40]. Prolamins are storage protein found mainly

*Essential amino acids profile of cowpea seeds. Black bars = upper values and gray columns = lower reference* 

with a low-fat content (1%) and bioactive compounds, such as phenols and

*DOI: http://dx.doi.org/10.5772/intechopen.96257*

polyamines [27, 28].

cowpea protein.

properties [34].

constitute 45% [37].

Cowpea is a legume consumed as a high-quality plant protein source in many parts of the world [10]. It is characterized by having significant contents

#### *Health Benefits and Industrial Applications of Functional Cowpea Seed Proteins DOI: http://dx.doi.org/10.5772/intechopen.96257*

of proteins (23–32%) and carbohydrates (50–60%), fibers, vitamins and nutrients, with a low-fat content (1%) and bioactive compounds, such as phenols and polyamines [27, 28].

Nutritional values and protein quality dependent on its amino acid composition, susceptibility to hydrolysis during digestion, purity and applied processing processing effects, such as heat treatments [29]. The nutritional and functional properties of pulses proteins depend on the nature of soluble fractions [12, 30]. Generally the protein content of cowpea differs along with the variety [12].

Cowpea has high protein and carbohydrate contents with a relatively fat-low content and a complementary amino acid pattern to that of cereal grains make cowpea an important nutritional food in the human diet [10]. Cowpea protein is rich in essential amino acids, particularly lysine, histidine and aromatic amino acids [31]. However, it is deficient in methionine and cysteine compared to animal proteins [32]. **Figure 1** shows the amino acid profile (essential amino acid) of cowpea protein.

The amino acid profile makes cowpea protein unique and of unquestionable quality [10]. The functional attributes of proteins like gelation, foaming, emulsification, thickening also drive the incorporation of isolated proteins in various foods like mayonnaise, baked foods and beverages [33]. The manner of converting the isolated proteins into powders also determines their functional properties [34].

In cowpea, protein types comprise globulins, albumins, glutelins and prolamins [12, 35]. Albumins and globulins are considered to represent the major storage proteins in cowpea [36]. Globulins represent most cowpea seed proteins and constitute over 51% of the total seed protein, while albumins approximately constitute 45% [37].

Glutelins have poor lysine content in cowpea [12]. Albumins has functional role in seeds as enzymatic and metabolic proteins (i.e. lipoxygenase, protease inhibitors and lectins) [38, 39]. Globulins has an important role as storage proteins and were mostly digested by proteases [38–40]. Prolamins are storage protein found mainly in seeds with high proline and glutamine content [41].

#### **Figure 1.**

*Grain and Seed Proteins Functionality*

calls pulses the world's most versatile superfood [6].

content and high total protein concentration [10].

the hard-to-cook defect that prolongs cooking time [24].

carried out in various areas of science.

**2. Cowpea functional proteins**

hydrophobicity [22, 25, 26].

advantages over other legume crops [17, 18].

potential [21].

production strategy designed to achieve food security and adequate nutrition [5]. In addition, pulses are a fordable and shelf-stable [4]. The American Pulse Association

Protein energy malnutrition (PEM) is one of the most severe public health problems in many developing countries [7]. Particularly, child malnutrition was

Cowpea (*Vigna unguiculata* L. Walp.) (2n = 2x = 22) [9] provides food for millions of people and is important in alleviating protein-calorie malnutrition [10]. Also is a good source of essential amino acids (e. g. Lys, His) and the aromatic AA [10, 11]. Because of its high crude protein content and a good balance of EAA, cowpea is usually considered as a complete food [12]. Cowpeas are also good sources of fibre, iron, zinc, and contain substantial amounts of bioactive compounds [13]. Cowpea has been promoted as a high-quality protein constituent of the daily diet among economically depressed communities in developing countries, with the aim of reducing the high prevalence of protein and energy malnutrition [14, 15]. Nutritionally, cowpea grain is the same as other pulses, with a relatively low-fat

Cowpea is a major alternative for the production of vegetable protein to be a culture of easy cultivation, low demand for soil fertility and adaptability and stability in all continents [16]. Cowpea ability to growth in low fertility and to subsist in soils where drought is a major constraint due to low and irregular rainfall confers

Cowpea are also used as green manure, employed in a rotary schemewith other annual crops or in fruit plantations to increase or sustain soil fertility [19]. Dried cowpea seeds can be used for making cake or the seeds could be boiled, mixed with sauce or stew and consumed directly [20]. In addition to its great economic, social and environmental importance, cowpea is a crop with great industrial

In the food industry, cowpea seeds is used in the production of canned and preserved foods, and in the production of isolated proteins with various applications (e.g. production or additives in flour, supplements for athletes and functional foods) [15, 19, 21–23]. However, a certain "underutilisation" of cowpea in food applications has been attributed to its beany flavour, presence of antinutrients and

The identification of the cowpea functional proteins and the investigation of the mode of action and application of these proteins aim to systematize information and contribute to the development of cowpea cultivation and the industrialization of this still underutilized culture, considering its great potential and studies already

Vegetable proteins are presented as functional, as they provide health benefits, in addition to the essential nutrient's characteristic of the species. Functional properties of proteins are important in food processing and food product formulation. Some of these properties are water/oil binding, emulsification, foam capacity and gelation. These properties depend on characteristics of proteins such as molecular weight, amino acid composition, net charge and surface

Cowpea is a legume consumed as a high-quality plant protein source in many parts of the world [10]. It is characterized by having significant contents

associated with 54% of deaths in children in developing countries [8].

**52**

*Essential amino acids profile of cowpea seeds. Black bars = upper values and gray columns = lower reference values found in the literature. Adapted from [10].*
