1. Introduction
Ending all forms of hunger by 2030, as outlined in the United Nations’ second Sustainable Development Goal (UN-SDG2), is a difficult but necessary endeavor, considering the short time remaining, the poor global health status, and the socioeconomic effects of hunger. Malnutrition is a grave issue on a global scale. About one-third of the world’s population is affected by malnutrition or concealed hunger owing to micronutrient deficiencies, which significantly threaten economic growth
[1]. Although the 1994 image of a dying child alongside a vulture waiting for food at a distance won the New York Times the Pulitzer Prize for Feature Photography, it also exposed the shocking reality of widespread global poverty, hunger, and unmet food needs. According to United Nations estimates, 821 million people worldwide were undernourished in 2018. Women and children are disproportionately affected by micronutrient deficiencies, which affect more than two-thirds of the world’s population overall. There are 2 billion iron-deficient individuals
[2], 2 billion iodine-deficient people, 150 million vitamin A-deficient people, and up to 3 million people in the world who are in danger of zinc insufficiency
[3][4][5]. Thus, providing sufficient quantities of nutritious food is one of the 17 sustainable development goals outlined by the United Nations. The lack of essential nutrients, notably minerals such as iron (Fe), zinc (Zn), and vitamin A, is one of the main causes of “hidden hunger”, especially in underdeveloped nations
[6].
Nutritional insecurity is a huge hazard to the world’s population, which is mostly dependent on a micronutrient-deficient cereal-based diet. Because of the poor overall quality of their diets, people often have several dietary deficiencies since these nutrient deficits are not mutually exclusive. The socioeconomic groups who are least able to achieve adequate dietary micronutrient intake are those who suffer the most. More than 1.3 billion people worldwide are estimated to rely on an income of less than USD 1 per day to exist
[7]. These mineral deficiencies are more common in underdeveloped nations for this reason. By closely relating agriculture to nutrition and health, as well as by developing agricultural and nutritional practices and health policies that take this requirement into account, the researchers can find sustainable answers to the problem of hidden hunger
[8]. For healthy and productive lifestyles, humans need at least 49 recognized nutrients at regular and sufficient levels
[9].
Until now, the primary goals of the agricultural system have been to boost crop productivity and grain yield, not to address human health. This strategy has caused a sharp increase in the lack of some micronutrients in dietary grains, which has increased nutrient deficiencies among consumers. Agriculture research in developing countries has increased calorically dense staple crop production and availability during the past 50 years, but not the production of non-staples high in micronutrients, such as vegetables, pulses, and animal products. It has become harder for the poor to afford a healthful diet due to the rising costs of non-essential goods
[10]. Biofortification has been developed as a new technique for combating the widespread scourge of hidden hunger, whose root cause is the exclusive reliance on staple foods for nutrition. Biofortification promises improved nutritional accessibility to the public by overcoming many obstacles and meeting this need.
2. Biofortification
Around the world, initiatives to biofortify foods are concentrated on iron, zinc, selenium, and vitamin A in particular. These efforts attempt to supplement and, in some cases, replace chemical fortification or dietary supplements. Since 2003, many researchers and their collaborators have proven that this plant-breeding-based approach to alleviating vitamin deficits in agriculture is effective. More than twenty million farm households in developing nations already cultivate and consume biofortified foods. The main beneficiaries of biofortification are women and children, whose needs are particularly high and frequently unmet
[11]. Farmers offer a solution via biofortification, which combines the micronutrient trait with other desired agronomic and consumer features. After meeting the family’s dietary needs, surplus biofortified crops can be sold to rural and urban retail businesses.
3. Need and Demand for Biological Fortification
With regard to specific biofortification techniques, plant breeding can raise the micronutrient levels of plants. Micronutrients are another category of essential nutrients that the human body requires in very minute amounts. These consist of vitamin A, iron, zinc, copper, copper, manganese, iodine, selenium, molybdenum, cobalt, and selenium
[12][13]. Numerous micronutrients control vital bodily and metabolic processes by working as cofactors for several enzymes in the human body
[14]. The main source of nutrients for people is agriculture; cereals, which are a staple of the human diet, fall short of providing all the nutrients that are needed daily. Therefore, nutrient-poor agricultural goods cannot support healthy lives and may instead cause illness, an increase in the risk of morbidity and death, a fall in the socioeconomic development of a nation, impaired development, stunted mental and physical growth, and diminished livelihoods
[15].
According to the United Nations’ Food and Agriculture Organization, 780 million of the world’s estimated 792.5 million malnourished people reside in developing nations
[16][17]. As can be seen in
Table 1, although most regions are on course or making progress toward reducing childhood stunting, far too many remain behind in meeting the other global nutrition targets, highlighting the need for increased urgency. While progress has been made in reducing wasting in Central and South America and the Caribbean, much more must be done in other regions where children continue to be at risk of this disease. Still a severe issue, the prevalence of child stunting has decreased in only a few places, despite widespread efforts to do so. The prevalence of childhood obesity is stagnating or even increasing in most places. The deterioration tendencies in East and Southeast Asia, as well as in Australia and New Zealand, are of particular concern. If the researchers want to reduce the percentage of overweight children to below 3 percent, they must make real progress in this area. This would also help slow the worrying increase in adult obesity, which is a problem in every area of the world. Trends have either remained stable or deteriorated in every region except Central and South America or the Caribbean, making it clear that no region is on course to meet the targets for lowering anemia in women of reproductive age. Similarly, no region is on track to reduce the percentage of infants born with a low birth weight, according to the most recent estimates.
Table 1. Various forms of malnutrition and their progress in various regions
[18].
Figure 1. The need for biofortification.
Among the various vitamins and minerals that are considered essential for human health, the deficiencies of iodine (I), Fe, Zn, and vitamin A are the most widespread forms of micronutrient malnutrition (28). The deficiency symptoms and management of these four elements are mentioned in
Table 2. The ability of erythrocytes to carry oxygen depends on iron, the core ion of hemoglobin. It also comprises the muscle protein myoglobin and several enzymes. Anemia, or a drop in hemoglobin levels in the blood, is caused by an iron shortage and impacts cognitive development, growth, and physical fitness. Worldwide, 38% of pregnant women and 43% of children under 5 have anemia. Additionally, low hemoglobin levels raise the risk of low birth weight and maternal death. Genetic predispositions, blood loss during menstruation, and illnesses such as malaria and other parasites all contribute to this effect
[26].
Table 2. Reasons, symptoms, management, and prevention of the major micronutrient deficiencies, based on
[26].
Nutrient |
Specific Function |
Reasons for Deficiency |
Symptoms |
Management and Prevention |
Iron |
Hemoglobin, various enzymes, myoglobin |
Poor diet and elevated needs (e.g., while pregnant and in early childhood); chronic loss from parasitic infections (e.g., hookworms, schistosomiasis, whipworms) |
Anemia and fatigue, impaired cognitive development, reduced growth, and physical strength |
Foods richer in iron and with fewer absorption inhibitors, iron-fortified weaning foods, low-dose supplements in childhood and pregnancy, and cooking in iron pots |
Iodine |
Thyroid hormone |
Except where seafood or salt fortified with iodine is readily available, most diets worldwide are deficient |
Goitre, hypothyroidism, constipation, growth retardation, and endemic cretinism |
Iodine supplements, fortified salt, and seafood |
Vitamin A |
Eyes, immune system |
Diet poor in vegetables and animal products |
Night blindness, xerophthalmia, immune deficiency, increased childhood illness, and early death, contributing to the development of anemia |
More dark green leafy vegetables, animal products, fortification of oils and fats, and regular supplementation |
Zinc |
Many enzymes, immune system |
Diets poor in animal products, and diets based on refined cereals (e.g., white bread, pasta, and polished rice) |
Immune deficiency, acrodermatitis, increased childhood illness, early death, complications in pregnancy, and childbirth |
Zinc treatment for diarrhea and severe malnutrition, and improved diet |
A healthy immune system and good eyesight depend on vitamin A, the lack of which raises the risk of blindness, contributes to anemia development and is linked to higher rates of infection and infant death. Around 190 million preschoolers worldwide suffer from vitamin A insufficiency
[26][27]. Iodine is necessary for the synthesis of thyroid hormones, and this requirement rises significantly during pregnancy and during childhood physical and cognitive development. Approximately 1.8 billion individuals globally do not consume enough iron in their diets. The insufficiency of iron is pervasive worldwide, except in nations where food is artificially enhanced with iodine
[26][27]. The body requires about 300 enzymes that contain zinc for metabolic functions, RNA and DNA synthesis, and immune system function. Zn deficiency poses a serious threat to more than 17.3% of the world’s population. A lack of Zn impairs the immune system, raises the chance of contracting infectious diseases and can harm a developing child, both during pregnancy and after birth
[26][27].
Biofortification offers two substantial competitive advantages: the capacity to reach underserved rural communities and long-term cost-effectiveness. Compared with the ongoing costs associated with supplement and commercial fortification programs, plant breeding produces biofortified planting material, rich in micronutrients, that farmers can cultivate at nearly no marginal cost. Once created, nutritionally enhanced crops can be tested in different environments and areas and tweaked, increasing the initial investment’s return. Once the micronutrient trait has been included in the fundamental breeding objectives of national and international crop development programs, agricultural research institutes incur few ongoing costs in terms of monitoring and maintenance.
Biofortified crops can also be used to reach rural people with limited access to diverse diets or other micronutrient therapies. Using the eating habits of women and children as a guide, target micronutrient values for biofortified crops can be determined. Biofortification provides farmers with a solution by merging the micronutrient features with other beneficial agronomic and consumer traits. After providing for the household’s nutritional needs, extra biofortified crops can be sold at retail establishments in both rural and urban areas. Crops that are biofortified can enhance human nutrition. Nutritionists can study the preservation of micronutrients in crops under typical processing, storage, and cooking circumstances to show proof of nutritional value. This practice ensures that the target group’s meals will still contain the right levels of vitamins and minerals
[28]. Genetic variations in terms of retention and chemical concentrations that impede or enhance micronutrient bioavailability can be considered. Nutritionists also study how much of the nutrients inserted into crops are absorbed, but they must start with models before undertaking controlled human studies. The ability of biofortified crops to improve micronutrient status must be demonstrated by absorption, but the regular use of biofortified meals must directly quantify the status change. To determine the effects of biofortified crops on micronutrient status and the functional markers of micronutrient status, such as tests of physical activity and cognition for iron crops, and tests of visual adaptation to darkness for vitamin A crops, etc., randomized controlled effectiveness trials are conducted
[29].
Biofortification breeding has necessitated the development or adaptation of cost-effective and rapid high-throughput analytical techniques for micronutrients, such as testing the mineral or vitamin contents of thousands of samples per season. Examples of these trait diagnostics include near-infrared spectroscopy (NIRS) and colorimetric carotenoid analysis methods. X-ray fluorescence spectroscopy (XRF) has become the method of choice for mineral analysis since it requires less pre-analytical preparation and permits non-destructive inspection
[30][31].
4. Biofortification Approach
Current treatments, including supplementation and industrial food fortification, are not sufficient to fully correct vitamin deficits. Biofortification fills this gap. Three basic methods—transgenic, conventional, and agronomic—involve the use of biotechnology, crop breeding, and fertilization techniques, respectively, to biologically fortify vital micronutrients into agricultural plants, as shown in
Figure 2. Plant breeding can raise the nutritional content of staple crops to the levels required for enhancing human nutrition without compromising yield or farmer-preferred agronomic features. The crop development process includes several steps, such as screening the germplasm for accessible genetic diversity, pre-breeding parental genotypes, creating and testing micronutrient-dense germplasm, undertaking genetic studies, and constructing molecular markers to lower costs and speed up the breeding process. Following the generation of promising lines, the resulting crops are tested under numerous target settings to determine the genotype x environment interaction (GxE), or the impact of the growing environment on micronutrient expression. The time that it takes for biofortified cultivars to reach the market has been sped up by robust localized testing. Based on the target populations’ food consumption habits, anticipated nutrient losses during storage and processing, and estimated nutrient bioavailability, a team of nutritionists, food technologists, and plant breeders can define nutritional breeding goals by crop
[32].
Figure 2. Different biofortification approaches to correcting nutrient deficiencies and improving yields.
Through improved fertilization in productive regions, agronomic biofortification can temporarily raise micronutrient levels. The most economical and straightforward method of biofortification is the application of fortified fertilizers enriched with micronutrients. However, the effectiveness of agronomical biofortification is largely dependent on soil composition, mineral mobility, and accumulation at specific places. Cost-effective but time-consuming, agronomic biofortification requires constant micronutrient administration to the soil or plants. The iron concentration in rice grains can be increased through biofortification by applying Fe foliar spray to rice crops
[33]. Fertilization is one method of agronomic biofortification that can raise the food’s levels of Fe, Zn, I, and Se. While deficiencies in Fe and Zn can be advantageous for both crops and consumers, deficiencies in I and Se have no negative effects on crop growth. The timing of foliar micronutrient treatment is found to be critical, in addition to the need to follow agronomic principles to maximize the micronutrient accumulation of Zn and Fe. Plant growth-promoting microbes can encourage plant growth as well as help to increase the movement of nutrients from the soil to the plant’s edible parts.
Bacillus,
Pseudomonas,
Rhizobium, and other species of soil bacteria can be employed to increase the phytoavailability of mineral elements
[34].
The transgenic approach can be a viable option for developing biofortified crops when there is little to no genetic diversity in the number of nutrients available in different plant types
[35]. It requires access to an endless genetic pool for the transfer and expression of desired genes from one plant species to another, regardless of their evolutionary and taxonomic status. Additionally, the only practical method for fortifying crops with a specific micronutrient when it does not naturally occur in them is through transgenic methods
[36]. The creation of transgenic crops has depended heavily on the capacity to recognize and explain gene function and then use these genes to change plant metabolism
[37]. High-lysine corn, soybeans with high levels of unsaturated fatty acids, cassava with high rates of provitamin A and iron content, and high-provitamin A golden rice are all successful instances of transgenic methods.
5. Compared Benefits of Biofortification
In comparison to many other methods for enhancing a person’s nutritional condition, biofortification has an advantage because it targets the whole populace via staple foods. Many processed and fortified foods are out of the reach of the poor, and incorporating them into daily meals through alternative channels, such as free distribution, involves a number of challenges, including raising knowledge of nutrition, presenting the manufactured product, and putting it into practice (which might be a difficult undertaking if the community is uneducated, as it is in the majority of such cases). As opposed to other techniques of fortification or supplementation, the cycle will continue without much ongoing expenditure after the crop is introduced with a new genome. Once this occurs, the new genotype will also be present in its products and seeds. The yield is unaffected by fortified seed. As shown in Figure 3, it also offers major indirect benefits, such as disease-resistant plants and increased farm output. Combating the issue of malnutrition can be achieved by improving the nutritious content of daily foods, the quality of plants or crops, and the genetic variety.
Figure 3. The benefits of biofortification.
This entry is adapted from the peer-reviewed paper 10.3390/su141811632