Improving Wheat Nutritional Quality through Biofortification

Wheat is an important cereal crop that contributes significantly to the human diet. Different parts of the wheat grain provide different nutrients. Wheat germ is rich in vitamins B and E, protein, unsaturated fats, minerals, and carbohydrates, while the bran consists mostly of insoluble carbohydrates, protein, traces of B vitamins and minerals, and some anti-nutritional factors such as phytic acid. The endosperm is the largest part of the grain and consists mainly of starch and protein. There are increasing concerns about the deficiency of vitamins and minerals in the human diet, a condition commonly referred to as “hidden hunger” that has serious and widespread consequences in developing countries where cereals are the main source of food and nutrition. The low bioavailability of essential micronutrients, especially iron and zinc in humans and some farm animals, contributes not only to micronutrient deficiency but also to phosphorus pollution. Existing interventions to provide micronutrients such as with pharmaceutical supplements or industrial fortification of food products are effective yet have some limitations particularly in rural settings. Biofortification, the production of new food crops with higher micronutrient densities, may be a more apt approach. For example, enhancing wheat micronutrient density and bioavailability could lead to both improved human health and more sustainable agriculture. This can be accomplished by understanding the genetic diversity of wheat iron and zinc content and the genetic and molecular factors underlying these traits. Fertilizer application to crops has the potential to complement the gains made through genetic biofortification. Progress made in both genetic and agronomic strategies for wheat iron and zinc biofortification including the enhancement of bioavailability will be reviewed in this chapter.