What is Biofortification?

In the video above, Professor Hettie Schönfeldt of the University of Pretoria talks about the South African food fortification programme.

Biofortification is different from fortification, but an understanding of both is useful when considering nutrition-sensitive approaches to agriculture and food security.

Fortification

Fortification is defined as the addition of one or more essential nutrients to a food, whether or not it is normally contained in the food. Fortification can be used to prevent or correct a demonstrated deficiency of one or more nutrients in the population, or in specific population groups.

Fortification normally involves the addition of nutrients during processing, such as the addition of minerals and vitamins to cereal flour after refining.

Fortification tends to involve staple foods which are consumed by the majority of the population.

For example, fortification is seen in

• Cereal flours (fortified with B vitamins, calcium, iron)
• Milk products (fortified with vitamins A and D)
• Salt (fortified with iodine).

The fortification of sugar with iron is controversial, because although it is a staple food, its high consumption leads to dental decay and obesity.

Fortification of infant foods (such as baby cereals) is also controversial, because it may discourage breastfeeding and encourage consumption of processed rather than homemade foods. Some fortified infant cereals are expensive and therefore not accessible to everybody. The levels of nutrient added to infant foods are unlikely to lead to excess intake but close monitoring is recommended to prevent infants consuming amounts that reach upper tolerable levels.

Biofortification

Biofortification is different from fortification as it involves the selection of crops that have high nutrient content. For example, orange sweet potato varieties have higher pro-vitamin A carotene compared to white or yellow varieties.

Over the last ten years, many other crops have been selected with high nutrient content, including rice, wheat, maize, cassava, sweet potatoes and common beans. Others are in development, including bananas, barley, cowpeas, groundnuts, lentils, millet, pigeon peas, plantains, potatoes, sorghum and yams.

These may arise out of natural selection or plant breeding efforts. For example:

• Crops which are high in pro-vitamin A include orange sweet potato, orange cassava and orange maize
• Crops which are high in iron include high-iron maize, high-iron beans, high-iron potatoes
• Crops which are high in zinc include high-iron maize, high-zinc beans

Many countries have promoted biofortified crops as one strategy to address nutrient deficiencies.

Biofortification Considerations

1. Consumer acceptability

Biofortification may change the sensory properties of foods, including their colour and taste. For example, orange varieties are, of course, orange, compared to their white or yellow counterparts. These differences may seem trivial, but sometimes farmers and consumers may not trust these varieties which look and taste different. Biofortification programmes are often supported with social behaviour change interventions, including cooking demonstrations and nutrition education.

2. Bioavailability and efficacy

The term ‘bioavailability’ refers to how much of the nutrient is released from the food matrix and absorbed by the human intestinal system. Nutrients in crops may be found entrapped in the matrix, may be bound to other components, or may require other components for absorption, limiting their availability. For example:

• Pro-vitamin A carotenoids are absorbed in the presence of fats. If the diet is low in fat, this important dietary component may be poorly absorbed.
• Iron and zinc may be bound to dietary fibre in bran, and these minerals may be poorly absorbed compared to iron and zinc found in animal products. Removing the bran, as is common practice, also removes these nutrients.
• Some foods contain phytic acid or phytate salts, which also bind minerals and reduce their availability.

Bioavailability is often not reflected in food composition tables. So while it may appear that some crops have high nutrient content, the nutrient may not entirely benefit the consumer.

Acceptance of Biofortification

Biofortified crops are gaining acceptance and popularity and researchers have worked to demonstrate that biofortified crops can improve nutrient status. Research shows that regular consumption of biofortified crops improves biochemical markers of the nutrient in question, and reduces prevalence of deficiency symptoms. However, some would argue that biofortification does not promote diversity, as it focuses on a single crop at a time.

Have your say:

Consider the following questions.

• What do you think of biofortification as an approach to improve nutrition? What are the pros and cons?
• Are you aware of any other examples of biofortification being used in your country or region?