Mitigating Global Food and Nutritional Insecurity: Role of Indigenous Crops

Abstract

Indigenous plants adapt well to marginal conditions, a situation that is essential for resilient agriculture and sustainable food systems in a rapidly changing global climate. These plants are known to be highly nutritious containing a wide array of antioxidants from their various parts including the leaves, stems, roots, branches, flowers etc. Polyphenols, flavonoids, isoflavonoids are major examples of these antioxidants which are chiefly found in many indigenous fruits, vegetables, nuts and seeds. The cultivation of these crops creates employment, providing a unique hotspot for biodiversity conservation as well as providing raw materials for most industries in the world. This review has also provided particular uses of these crops and their potential to combat food insecurity. The rapid exploitation of these crops and the lack of knowledge on their conservation is a major problem to global nutritional and food insecurity. Additionally, the rapid growth in population and technology will significantly impact the productive uses of these vital species. It is therefore crucial to provide a comprehensive review on the role of some of these plants in combating the food security issues globally.

1. Introduction

It is an undeniable fact that the consumption of quality food is crucial for the continued survival of living things on this planet. The basic part of the existence of man has been food. Through the ages, we have amassed a lot of knowledge on the use of food to promote healthy growth in children and youth, to maintain good health throughout life, to satisfy unique needs of pregnancy and lactation, and to utilize it to heal from sickness [1]. Food is that which nourishes the body and may also be defined as anything eaten or drunk, which meets the needs for energy, building, regulation and protection of the body. Consuming the proper foods in the right proportions can promote good nutrition and health, which may show in our physical appearance, productivity and emotional well-being. Food functioning in the body is referred to as nutrition, and this definition encompasses everything that occurs to food from the time it is consumed until it is used for various bodily activities. The body requires nutrients in sufficient quantities in order to grow, reproduce, and live a normal, healthy life. Water, proteins, lipids, carbohydrates, minerals, and vitamins are the basic building blocks or constituents of nutrients. There are several nutrients in each of the groups: proteins, fats, carbohydrates, minerals and vitamins; hence the plural form of these words has been used.

2. The concept of food security

The international communiity has made a lot of efforts to define the over all idea of food security and how it has evolved. One of the most basic shifts has been the change from an initial idea where food security was known to be similar to the reliable availability of food towards the contemporary notion in which food is one of the elements of a complex social context that determines livelihoods. The issue of food security is largely determined by this social context and the relative power dynamics among the various interest groups that make up it [2]. “Food security, at the individual, household, national, regional, and global levels [is achieved] when all people, at all times, have physical and economic access to sufficient, safe, and nutritious food to meet their dietary needs and food preferences for an active and healthy life,” is the consensus that has emerged from the global debate [3]. Thus, physical availability of food, economic access to food, and proper food utilization—which is a result of the body’s capacity to process and use nutrients—are the three main components of the household food security architecture [4, 5, 6].

Availability in sufficient quantity of food of an appropriate nature and quality in all parts of the national regions, regardless of its origin (local production, imports or food aid).

Access by all people to the resources needed to obtain the food needed by them for a nutritionally adequate diet. Examples of such resiurces are financial resources, rights of access to the resources required to produce food or to receive it from others.

Stability of access to food, i.e. the assurance of access by people to food even in the midst of natural or economic instabilities.

3. State of global food and nutritional security

FAO [7] reported that, the prevalence of malnutrition in the world is 10.8% and 11.0%, that is, 794 and 815 million people according to the results of 2015 and 2016, respectively. This means that, despite all of our combined efforts, there are more hungry and malnourished individuals than ever before. The World Bank said in 2017 that 45 nations were home to 83 million hungry people. Undernourishment affects no more than 5% of the population in industrialized regions, 13% of the population in developing regions, 20% of the population in African countries, and 13% of the population in Asian countries. Food security has clearly declined in a number of nations in Africa, Southeast Asia, and West Asia. Furthermore, the FAO [8], reported that, under the threat of the COVID-19 pandemic, the number of individuals who experience hunger worldwide grew further in 2020.The Prevalence of Undernourishment (PoU) increased from 8.4 percent to roughly 9.9 percent between 2019 and 2020 after remaining essentially stable from 2014 to 2019, making it more difficult to achieve the Zero Hunger objective in 2030.The 2020 projections ranges from 9.2 to 10.4 percent, based on the assumptions made to reflect the uncertainties around the assessment. As per population, it is predicted that between 720 and 811 million people worldwide would face hunger in 2020. With estimates ranging from 70 to 161 million, the mean of the projected range (768 million) indicates that 118 million more individuals experienced hunger in 2020 than in 2019. The statistics demonstrate pervasive and unsettling geographical disparities. In 2020, 21% of Africans (about one in five of the continent’s inhabitants) experienced hunger, which is more than twice the rate in any other region. 3 percentage points have been added to this during the course of a year. This is followed by Latin America and the Caribbean (9.1 percent) and Asia (9.0 percent), with increases of 2.0 and 1.1 percentage points, respectively, between 2019 and 2020. More than half (418 million) of the world’s undernourished (768 million) people live in Asia, and more than one-third (282 million) reside in Africa, with Latin America and the Caribbean accounting for around 8% of the total (60 million). In 2020, there were over 14 million more individuals in Latin America and the Caribbean, about 57 million more people in Asia, and 46 million more people in Africa who experienced hunger than in 2019. According to the Food Insecurity Experience Scale, there has been a gradual increase in the percentage of people worldwide who experience moderate or severe food insecurity, from 22.6 percent in 2014 to 26.6 percent in 2019. Then, it increased to 30.4 percent in 2020, the year the COVID-19 pandemic broke out worldwide, nearly tripling its prior five-year average. With a rise of 320 million people in only one year, from 2.05 to 2.37 billion. Thus, roughly one in three people worldwide did not have access to enough food in 2020: Of those, about 928 million (11.9 percent of the world’s population) or close to 40 percent experienced extreme food insecurity. In 2020 compared to 2019, there were over 148 million more individuals who were severely food insecure [8]. The regions with the largest increases in moderate or severe food insecurity between 2019 and 2020 were Latin America and the Caribbean (9 percentage points) and Africa (5.4 percentage points), whereas Asia only saw a 3.1-point increase. The prevalence of food insecurity increased for the first time since the start of the Food Insecurity Experience Scale (FIES) data collecting in 2014, even in Northern America and Europe, where the lowest rates of food insecurity are observed. In the year of the COVID-19 pandemic, the gender disparity in the incidence of moderate or severe food insecurity has widened even more globally, with the prevalence of such insecurity among women being 10% greater than that of men in 2020 as opposed to just 6% in 2019. To better understand the relationship between these crucial food access factors and the trends in the various forms of malnutrition, it is useful to track the price of healthy diets and the number of people who cannot afford them. An estimated 3 billion people were unable to afford a nutritious diet in 2019 due to the high cost of healthy meals and persistently high levels of income inequality. The majority of these individuals reside in Asia (1.85 billion) and Africa (1.0 billion), although millions of people in Latin America and the Caribbean (113 million), Northern America, and Europe also lack access to a healthy food (17.3 million) [8].

4. Major causes of food insecurity

The causes of recent increases in hunger and the slowing down of efforts to reduce all forms of malnutrition include conflict, climate variability and extremes, and economic slowdowns and downturns (which are currently being compounded by the COVID-19 epidemic). High and enduring levels of inequality make it harder to mitigate their negative effects. Additionally, millions of people worldwide experience food insecurity and various forms of malnutrition because they are unable to pay for a balanced diet. These major drivers are distinct but not mutually exclusive, as they interact to the detriment of food security and nutrition by creating multiple, compounding impacts at many different points within our food systems.

Household food insecurity (HFI) is as a result of poverty, poor health of household member(s), as well as substandard livelihood and inadequate household management strategies [9]. Nutritional and health security are closely related to but not the same as food security. When the body tissues are exposed to enough amounts of nutrients and other essential substances, people can achieve nutrition security. Health care access security, access to other fundamental human needs, such as sufficient sanitation, and household food security together contribute to nutrition security. Food security and the other determinants of nutrition security are linked with each other [9].

For instance, a family with little financial means might decide not to seek medical care for a child or to not purchase prescribed medications. For food security to be a reality, households need to have unrestricted access to a healthy and nutritious diet. The availability of food in the nation, region, and communities where the homes are located, as well as enough financial means, are prerequisites for access to a nutritious diet The amount of food that is readily available on a national scale depends on how much food is produced domestically, imported, and exported, as well as how much food is wasted or fed to animals. Therefore, ensuring household food security and nutrition security globally depends on maintaining a cheap and sustainable nutritious food supply. Given that the Sustainable Development Goals (SDGs) of the United Nations call for eradicating hunger, achieving food security and improved nutrition, and promoting sustainable agriculture globally, it is crucial to understand and address issues relating to household food security, such as climate change, agricultural commodity price regulations, armed conflicts, and ultimately the health of our planet [10].

5. Consequences of household food insecurity

HFI is a significant biological and psychosocial stressor that, through several pathways, may put people at risk for poor mental, social, and emotional development throughout their lives. The potential connections between HFI, inadequate dietary intakes, nutritional status, and general wellbeing are elements of a biological process. An example of this is a recent study from the United States that details the extremely poor nutritional quality of people with low incomes who are at risk of food insecurity [11]. They consumed extremely little fish, fruit, whole grains, and vegetables in their diets. Indeed, there is a substantial correlation between this dietary pattern and a higher risk of obesity, the metabolic syndrome, chronic diseases including diabetes, and early death [12]. Among those who experience food insecurity, a psycho-emotional pathway includes worry/anxiety, a sense of isolation, deprivation and alienation, distress, and unfavorable family and social interactions [13].

5.1 Poor child development

HFI is a potent stressor that affects children’s psycho-emotional, social, behavioral, and intellectual growth in both direct and indirect ways, including problem internalization (such as depression) and externalization [13]. Quantitative research has demonstrated that HFI has an impact on a child’s development in addition to the independent impacts of the conventional markers of poverty, such as household income and parental education [13]. The impact of HFI on child development is likely to be influenced by nutritional indicators as well as by psycho-emotional factors affecting how the family functions. Qualitative studies have demonstrated that HFI causes powerful psycho-emotional reactions, such as anxiety, sadness, or anger [14].

5.2 Infectious illnesses

In nations as diverse as Brazil and Haiti, HFI has been linked to an increased risk of childhood malaria, diarrhea, upper respiratory infections, and hospitalizations due to serious infectious diseases. This association may be due to inflammation and a weakened immune system [15, 16].

5.3 Stunting, obesity and chronic diseases

In Brazil, Mexico, and other Latin American nations and areas of the world, HFI has been linked to the double burden of malnutrition, or the coexistence of stunted children and obese mothers living in the same household [17, 18]. Additionally, in Mexico, Ecuador, and other nations, HFI has been linked to significant non-communicable disorders such type 2 diabetes and hypertension [19, 20] which is likely to be related to low dietary quality [21] and stress [19] resulting from HFI.

5.4 Poor mental health among children, youth and adults

In the USA, HFI has been linked to depression and suicidal thoughts in young people, and it has been established that HFI is a major cause of maternal depression worldwide. In turn, maternal depression is a significant risk factor for the poor psychosocial, emotional, and behavioral development of children [22, 23, 24, 25].

5.5 Suboptimal sleep patterns

Physical and mental health are significantly impacted by lack of sleep. Among Mexican adults and low-income Latinos with type 2 diabetes in the USA, HFI has been linked to less-than-ideal sleep habits, and this relationship is influenced by stress and anxiety [26].

5.6 Social disruption

The widespread riots and social unrest brought on by the economic crisis and significant food inflation experienced in 2008 have been cited as evidence that HFI is a significant global cause of social unrest and internal struggle [27]. In fact, food scarcities cause such societal disruption that they are viewed as a serious threat to the disintegration of states.

5.7 Environmental sustainability

According to the recent Lancet Series on Planetary Health [28]. The stability of the world’s food systems is known to be seriously threatened by the deterioration and destruction of natural ecosystems, which in turn threatens crop diversity. Particularly, climate change has been identified as a key factor in the global destruction or harm to ecosystems. Therefore, preserving environmental sustainability is a major problem for both planetary and human health, making it essential to act right away. It is critical for citizens to be informed about the significance of individual lifestyle choices on the future sustainability and food security of the world since customers drive demand, which in turn drives industry decisions [21]. Similarly, it is critical for governments to develop sustainability policies that create the framework for which consumers can make these choices.

6. The sustainable development goals and food security indicators

According to the United Nation’s Sustainable Development Goals, it envisaged that by 2030, end hunger and ensure access by all people, in particular the poor and people in vulnerable situations, including infants, to safe, nutritious and sufficient food all year round. Based on the underlying idea of equitable and sustainable economic growth, the SDGs are a set of 169 objectives and targets, that countries have committed to achieving by 2030. The achievement of all 17 goals from eradicating poverty and hunger to promoting gender justice and planetary sustainability, requires a secure supply of food [10].

7. Food insecurity mitigating strategies-role of indigenous crops

There are a number of mitigation strategies which have been outlined to address the issue of global food and nutritional insecurity of which the cultivation of healthy indigenous crops are included. The World Trade Organization (WTO) stated that “Indigenous agriculture and biological resources are vitally important to the economies, cultures, environment, food security and livelihoods of sub-Saharan Africa [29]. Work done by researchers such as Mbhenyane [30] suggests that there may be great potential for African food systems and its food security if indigenous plants were studied more extensively and included more often as mainstream foods.

With 7000 species used historically as food sources and for a variety of other purposes, indigenous tropical food crops (ITFCs) offer more diversity than alien foods [31, 32]. Given the need for dietary diversity and growing worries about environmental effects like climate change, ITFCs are well-positioned to offer food options that may enhance nutrition, broaden dietary options, and be climate change-adapted [33].

Traditional foods provide a significant chance to diversify the food supply as well as serving as a representation of legacy, identity, and culture. Many cultural identities of many ethnic groups depend on these foods [34, 35]. Therefore, it’s crucial to preserve various eating customs, especially those related to food preparation and consumption, as this information might.

Moreover, African Indigenous vegetable and fruit crops are native plants that are utilized for food and medicine. Though these plants have been semi domesticated while others develop as volunteer crops, they have the potential to increase economic development and household nutrition. They are rich in vitamins and minerals with some having high quantities of lysine and essential amino acid which is lacking in fiber and cereal diets.

The focus of this chapter review will be on some indigenous leafy vegetable and fruit crops. Examples of such indigenous leafy vegetables are Solanum macrocarpon (African eggplant), Amaranthus spp., Corchorus olitorius L. (vegetable jute) and Hibiscus sabdariffa L. (Roselle). The indigenous fruit crops of interest in this report are Averrhoa carambola (star fruit), Irvingia gabonensis (wild bush mango), Annona muricata L. (soursop), Synsepalum dulcificum (miracle berry), Chrysophyllum albidum (African star apple) and Dialium guineense (African black velvet tamarind). Other crops include; Vernonia amygdalina (Bitter leaf), Solanum torvum (turkey berries or wild eggplant), Citrullus colocynthis (colocynth, bitter apple, wild-gourd, egusi) and Piper guineense (African black pepper).

S. macrocarpon (Figure 1), originated in West Africa and is cultivated in East and Central Africa where its young stems and fresh leaves are widely consumed [36]. The leaves of African eggplant are considered to be of high nutritional value specifically protein, fat, crude fiber, calcium, and zinc [37, 38]. also reported that, S. macrocarpon leaves contain considerable amounts of Sulfur-containing amino acid methionine, polyphenols, especially the flavonoids which is capable of contributing to strong antioxidant properties [36, 39] reported that the leaves consist of 86% water, 6% carbohydrates, 4.6% protein, 1.6% fibers and 1% fat, 14.0% glutamic acid, 13.3% aspartic acid, 7.5% leucine and 6.6% arginine.

Figure 1.

Solanum macrocarpon (African eggplant).

Amaranthus (Figure 2) is a popular vegetable in Bangladesh, South-East Asia, and Africa. According to [40], the stems and leaves of Amaranthus are a good source of carotenoids, proteins, the essential amino acids methionine and lysine, dietary fiber and minerals such as calcium, potassium, magnesium, copper, phosphorus, iron, zinc and manganese are useful to humans. Amaranthus is also reported to be rich in pigments, such as chlorophylls, carotenoids, amaranthine, betalains, anthocyanin, betacyanin and betaxanthins [41] and natural antioxidant phytochemicals, such as vitamin C, beta carotene, flavonoids, and phenolic acids These natural antioxidant phytochemicals protect the human body against cardiovascular diseases, cancer, arthritis, atherosclerosis, cataracts, retinopathy, emphysema, and neurodegenerative diseases [42, 43, 44].

Figure 2.

Amaranthus.

Corchorus olitorius L. (Figure 3), is an annual green dicotyledonous leafy vegetable that originated in Africa. It is an important leafy vegetable in the tropics; Egypt, Sudan, India, Bangladesh, and the Caribbean, in tropical Asia such as the Philippines and Malaysia, and in North Africa and the Middle East, including Lebanon, Palestine, Syria, Jordon, Tunisia, Turkey, and Cyprus [45]. The leaves of C. olitorius L. are used as vegetables. According to [46], edible jute has palatable plant parts rich in lipids, proteins, crude fiber, carbohydrate, vitamins (A, C, E) and the minerals calcium, sodium, potassium, phosphorus and iron. Ramadevi [47] also reported that it contains triterpenes, glucoside, flavonoids, saponins, β-sitosterol, fusidic acid, capsularin and scopoletin.

Figure 3.

Corchorus olitorius L. (vegetable jute).

Hibiscus sabdariffa L. (Figure 4), is native to Asia (India to Malaysia) or Tropical Africa and is widely grown in tropics like Caribbean, Central America, India, Africa, Brazil, Australia, Hawaii, Florida and Philippines as a home garden crop [48]. The fresh calyces of Roselle are reported to be rich in ascorbic acid, riboflavin, niacin, calcium, carotene and iron [49, 50]. Cisse et al. [51], reported that Roselle is rich in amino acids and mineral salts. It was also reported in early studies that Roselle contains protein, carbohydrate, vitamin C, β-carotene and iron [52, 53].

Figure 4.

Hibiscus sabdariffa L. (Roselle).

Averrhoa carambola (Figure 5), is cultivated extensively in South-East Asia for its fruit [54]. Star fruit is considered a rich source of natural antioxidants and minerals such as magnesium, iron, zinc, manganese, potassium, and phosphorous and can be eaten raw or processed into juices, jams, salads, or pickles [55]. According to [54], star fruit is rich in natural antioxidants such as vitamin C, β-carotene, and gallic acid and it contains 60% of cellulose, 27% of hemicelluloses, and 13% of pectin approximately.

Figure 5.

Averrhoa carambola (star fruit).

Irvingia gabonensis (Figure 6), Is native to West and Central Africa where it is cultivated for both its pulp and seeds (nut). Studies on the chemical properties of the fresh seeds identified eighteen (18) amino acids as well as appreciable amounts of nutrients, vitamins and minerals such as calcium, magnesium, potassium, sodium, phosphorus and iron. International Vitamin A Consultative Group (IVACG) reported that, Irvingia seeds contain 2.12% monosaturated fatty acids, lauric acid (27.63%), 0.27% polyunsaturated fatty acids and myristic acid (61.68%). The pulp of Irvingia contains 81 g water; 15.7 g carbohydrate; 0.9 g protein; 2 g fat; 40 mg phosphorus; 20 mg calcium; 7 mg vitamin C and 2 mg iron. The pulp also contains flavor compounds such as cinnamic acid; zingiberene; dodecanal and dodecanol.

Figure 6.

Irvingia gabonensis (wild bush mango).

Annona muricata L. (Figure 7), is native to the warmest tropical areas in South and North America and is widely distributed throughout tropical and subtropical parts of the world, including India, Malaysia and Nigeria, Australia, Africa [56]. According to [57], soursop contains major minerals such as potassium (K), calcium (Ca), sodium (Na), copper (Cu), iron (Fe) and magnesium (Mg), which can help provide essential nutrients and elements to the human body. Morton et al. [58], evaluated the composition of soursop and reported that it contains 53.1–61.3 Calories, 82.8 g Moisture, 1.00 g Fat 0.97 g Protein, 14.63 g Carbohydrates, 0.79 g Fiber, 60 g Ash, 10.3 mg Calcium, 27.7 mg Phosphorus, 0.64 mg Iron, 0 Vitamin A (β-carotene), 0.11 mg Thiamine, 0.05 mg Riboflavin, 1.28 mg Niacin, 29.6 mg Ascorbic acid, 11 mg Tryptophan, 7 mg Methionine and 60 g Lysine. Abbo et al. [59] studied the nutrient composition of soursop fruit, he reported that soursop fruit contains 81.9–93.6% carbohydrate (glucose and fructose), 278 mg K, 27 mg P, 14 mg Ca, 3.3 g Fiber and 0.3 g/100 g Fat.

Figure 7.

Annona muricata L. (soursop).

Synsepalum dulcificum (Figure 8), was first discovered in West and Central Africa, specifically in Congo, Ghana and Nigeria [60, 61]. The berries are a good source of both essential amino acids (lysine, leucine, isoleucine, phenylalanine, threonine etc.) and non-essential (glycine, proline, serine, tyrosine) amino acids [62]. Miracle fruit contains highly essential antioxidantive phytochemicals like epicatechin, rutin, quercetin, myricetin, kaempferol, gallic, ferulic and syringic acid, delphinidin glucoside, cyanidin galactoside and malvidin galactoside, a-tocotrienol, a- and c-tocopherol and lutein. Its proximate berry has been reported by He et al. [61] to include ten different fatty acids in the seed oil with a total unsaturated fatty acid content of 52.7%. Vitamins A, C, D and K were reported to be present. The berry was reported to be high in vitamin C [61, 63]. The fruit pulp produced high amounts of mineral content of Ca (100 ppm), Fe (24.20 ppm), Zn (9.49 ppm), Cu (6.22 ppm), Cr (0.01 ppm) and Co (0.01 ppm) with no lead detected. Nkwocha et al. [63] reported a high amount of flavonoids (57.01%) in Miracle berry. Tryptophan (8.06%), histidine (0.4%), isoleucine (0.7%), leucine (0.6%), lysine (0.6%), methionine (1.05%), phenylalanine (0.7%), threonine (1.1%), and valine (0.69%) are the essential and non-essential amino acids that are profiled in this plant. According to Lim [64] the principal compound of the fruit, “miraculin” is made up of sugars (glucosamine, mannose, fructose, xylose, and galactose), Nitrogen, Carbohydrates, and nearly 191 amino acid residues.

Figure 8.

Synsepalum dulcificum (miracle berry).

Chrysophyllum albidum (Figure 9), is originated from the central, eastern and West Africa and is common in both urban and rural centres in Nigeria. It is reported as an excellent source of vitamin C, iron [65]. It is also known to be rich in minerals especially K (potassium) and Mg (magnesium) [66, 67]. According to Okoli an Okere [68], African star apple is a rich source of anti-inflammatory and anti-hemorrhoidal compounds.

Figure 9.

Chrysophyllum albidum (African star apple).

Dialium guineense (Figure 10), Is found in Central and West African countries such as Cameroon, Central African Republic, Chad, Benin, Burkina Fasso, Ivory Coast, Ghana, the Guineas, Liberia, Mali, Senegal, Sierra Leone, and Togo [69]. It is rich in minerals such as magnesium (Mg), sodium (Na), iron (Fe), potassium (K) and beta-carotene (Vitamin A), copper (Cu), sugars and tartaric acid, citric acid, malic acid, ascorbic acid and Niacin. As anticipated, this fruit also has high levels of anti-oxidant.

Figure 10.

Dialium guineense (African black velvet tamarind).

Vernonia amygdalina (Figure 11), is small shrub used as a leafy vegetable and grows in tropical Africa. It is reported to be have been used to alleviate micronutrients malnutrition because the leaves are rich in vitamins and mineral elements including potassium, iron, phosphorus, calcium, copper, zinc, ascorbic acids and folic acid [70]. The leaves and young shoots of Vernonia amygdalina are used as a green vegetable in soups and stews and in Nigeria and in some other African countries [71]. According to Musa et al. [72] leaves are a rich source of proteins, a-carotene, vitamin C, iron, phosphorus, magnesium, calcium, copper, sodium, zinc and potassium. (Oyowele et al. [73] also reported bitter leaf to contain high amounts of alkaloids and flavonoids hence considered to have anti-inflammatory activity.

Figure 11.

Vernonia amygdalina (bitter leaf).

Solanum torvum (Figure 12) is native to Africa and West Indies [74]. It is distributed in the tropical and subtropical mainly in India, China, Pakistan, Philippines and tropical America [75]. Its fruits and leaves are eaten as vegetables in soups and stews [76]. S torvum fruits are reported as a good source of fiber, calories, proteins, vitamins and minerals [77]. It is also reported to be high in calcium, iron, zinc, phosphorus, vitamin C and fatty acids.

Figure 12.

Solanum torvum (Turkey berries or wild eggplant).

Citrullus colocynthis (Figure 13), originated in the tropical regions of Asia and Africa. It is a vine plant found in the arid region which grows in sandy soil and is now extensively grown in the Mediteranean region and Sahara-Arabian phyto-geographic region of Africa [78]. In India, it is usually found in sandy lands of Northern West region such as Sind, Punjab, Central region, Southern region and Coromandal coastal area [79]. According to National Research Council [80], it contains high amount of protein (30%), 10% carbohydrates, 4% ash content and 3% of fiber content. It is also reported to contain nutritional compounds and different bioactive compounds such as alkaloids, essential oils, flavonoids, glycosides etc. C. colocynthis contains a specific bioactive compound named as curcurbitacins (A, B, C, D, E, I, J, K and L) as well as colocynthosides (A and B) respectively [81]. In addition to the high oil content of C. colocynthis seeds, it is also a rich source of protein and contain all essential amino acids in appropriate amount which makes the protein quality of its seeds superior and equally important as legumes [80]. C. colocynthis seed was considered a potential source of calcium (Ca) and potassium (K) in concentration at 569 mg/100 g and 465 mg/100 g respectively. A report by Zaini et al. [82] stated that C. colocynthis seeds contain iron (Fe), zinc (Zn) and phosphorus (P) in abundant amounts as well as considerable amount of calcium (Ca) and niacin.

Figure 13.

Citrullus colocynthis (colocynth, bitter apple, wild-gourd, egusi, etc.).

Piper guineense (Figure 14) is native to tropical Western Africa [83]. This is a spice plant with more than 700 species in the tropical and subtropical regions of the world [84] and it is commonly called Ashanti pepper, Benin pepper, Guinea pepper, false cubeb, Uziza in Igbo and Iyere in Yoruba [85]. According to Nwankwo et al. [86], the proximate analysis of P. guineense shows it contains crude protein, fat, carbohydrate, vitamins and minerals. It is also said to contain considerable amounts of vitamin C [87]. A study conducted on P. guineense leaves by Nwankwo et al., [86] revealed that it is high in ash which implies it is high in mineral content: copper (Cu), zinc (Zn), calcium (Ca), magnesium (Mg) and potassium (K) [88]. P. guineense contains vitamin A and traces of vitamin B1, B2 and E. According to [89]. the proximate composition of P. guineense seeds shows that the seeds contain 6.33 + 0.02% Ash, 8.79 + 0.01% Crude fiber, 9.89 + 0.07% Crude fat and 5.86 + 0.04% Crude protein. There are appreciable amounts of essential minerals such as Calcium (Ca), Magnesium (Mg), Potassium (K), Sodium (Na), Phosphorous (P) and Iron (Fe).

Figure 14.

Piper guineense (African black pepper).

8. General uses of indigenous crops in combating food and nutritional insecurity

Many rural communities have access to traditional crops that are rich in micronutrients, which are likely to serve as a long-term strategy to eliminate food insecurity. The diversity of indigenous crops has the potential to augment the nutrient composition of family diets and may contribute to household food security and the alleviation of hidden hunger which is a result of a lack of dietary diversity, usually linked to poor consumption of fruit and vegetables in general. Different nutrients found in food keep the body healthy. It is essential to eat a variety of foods in order to get all the vitamins and minerals required from the diet. Essential nutrient content in food is affected by a number of things, including how it was prepared, the temperature at which it was cooked, how long it took before it was removed from the heat source, etc. Cooking and processing can damage some nutrients and phytochemicals in plant foods. Fruits and vegetables quickly lose their nutritional value.

In order to preserve the nutrients in vegetables, it is therefore advised to avoid overcooking them. Households should employ a variety of methods for preparing vegetables, such as sautéing, steaming, baking, and stir-frying. Vegetables that can be eaten raw can be used in salads. Vegetables should be cooked with very little water and at a low temperature. Soups and stews are excellent ways to retain nutrients that are typically lost in cooking water. Solanum macrocarpon (African eggplant), Amaranthus spp., Corchorus olitorius L. (vegetable jute), Vernonia amygdalina (Bitter leaf), Solanum torvum (turkey berries or wild eggplant), Citrullus colocynthis (colocynth, bitter apple, wild-gourd, egusi) and P. guineense (African black pepper) are all indigenous vegetables used in the preparation of soups and stews where they are found in West Africa. For continuous availability of these vegetables in their fresh state, folks are encouraged to go into the cultivation of these vegetables to reduce the travel and storage time, buy fresh local produce, shop often and eat produce soon after it has been purchased.

Fruits should either be consumed unprocessed or transformed into juice and concentrates. Indigenous fruits such as Averrhoa carambola (star fruit), Irvingia gabonensis (wild bush mango), Annona muricata L. (soursop), Synsepalum dulcificum (miracle berry), Chrysophyllum albidum (African star apple) and Dialium guineense (African black velvet tamarind) can be consumed fresh or made into juice or smoothies. This will create employment for the youth and contribute to sustainable development. Increased consumption of these indigenous crops will undoubtedly lead to greater demand, increased production and creation of markets and will thus enhance rural economies.

9. Conclusion and wayforward

Without a doubt this review has elucidated information on the concept of food security and the empirical evidence on the current state of the global food and nutritional security whiles outlining the usefulness of some selected indigenous crops which can serve as healthy foods for consumption and raw materials for industrial uses. It has also provided the direct causes and consequences Household Food Insecurity has brought. The COVID-19 pandemic has been a huge setback such that many economies have not been able to recover and thereby making it difficult for the achievement of the hunger eradication agenda envisaged the UNSDGs in 2030. Even though indigenous crops have been known to be of advantage in reducing hunger and malnutrition this review made it clear that further research in this area is imperative, more studies are required to contribute new knowledge to science, hence increasing awareness on traditional uses and management of such crops. Additionally, most African countries, the ethno-botany of wild food resources is poorly documented and patchy, consisting of lists of plant names, providing little to no information on their use and management.

Conflict of interest

The authors declare no conflict of interest.