By Angeline Zengeya (Nutritionist, Agriprenuer)
Contact: +447909394989; [email protected]
Sustainable development goal 2 (SDG2) aims to fight hunger, achieve food security and improved nutrition and promote sustainable agriculture. The triple burden of malnutrition, undernutrition, hidden hunger and overweight populations across the world threatens the survival, growth, health and well-being and development of the younger generation.
In this article, the aim is to attempt to address hidden hunger using one of many strategies – biofortification.
Hidden hunger or micronutrient deficiencies occurs when the body lacks essential minerals and vitamins that are required in small quantities for growth development and overall health. Unlike calorific hunger, hidden hunger can occur without the accompanying energy deficit, mainly due to the lack of dietary diversity.
Conventional fortification has been of interest in the fight against hidden hunger for the past few decades. It aims to increase nutrient content during post-harvest processing.
On the other hand, biofortification aims to increase nutrient levels and their bioavailability in crops during plant growth. This can be done through agronomic practices, conventional plant breeding or modern biotechnology techniques.
Agronomic Practices
This involves the soil or foliar application of inorganic fertilisers and the supplementation of micronutrient media to soilless cultivated food. It has proved to be successful in enhancing the micronutrient content in a variety of microgreens and staple foods like maize, wheat, potatoes and rice. The use of inorganic fertilisers is effective, relatively simple and quick.
It does have drawbacks which include detrimental environmental pollution, expensive and labour intensive. The timing of application is critical to success of the strategy and genetic differences in crops also affect the uptake of fertilisers.
The good news is that, organic fertilisers obtained from plant or animal sources such as manure have also shown to be effective in biofortification. Biofertilizers – containing microbial inoculants and Nutri-priming – soaking seeds in solutions containing nutrients are also effective agents.
Conventional Plant breeding
Crossbreeding crops with high nutrient content with those that have desirable agronomic traits has been successful in the development of orange-fleshed sweet potatoes rich in beta-carotene (Vitamin A precursor). It aims to improve the concentration and bio accessibility of minerals and vitamins in crops of similar species by utilising their genetic differences, therefore improving nutritional quality without compromising other agronomic traits.
The process is time consuming, as the selection takes up to the sixth generation before a cultivar can be released by the breeders. There are strategies that can be employed to expedite the process and these can be expensive. It is also critical to do extensive testing in diverse environments in order to maintain the enhanced nutritional trait.
Despite all mentioned above, biofortified crops by conventional breeding is more widely accepted by society, it is cost effective particularly to small holder farmers who eat what they grow and more sustainable for the environment.
Biotechnology
Transgenic techniques are molecular techniques that transfer genetic material (DNA) from one crop to another in order to improve the nutrient production or disease resistance and make the host crop rich in nutrients. Crops can undergo gene editing which re-writes an existing gene to change its function. Alternatively, genes which code for different nutrients can be stacked in a crop to make it rich in numerous nutrients. Golden rice is an example of a crop that has been enriched with beta carotene.
Biofortification is not a one stop solution to end hidden hunger but one of several that can be used. Particularly in marginalised populations who cannot afford enough fruits, vegetables, legumes, fish and other essential nutritional requirements, biofortification of staple food crops can be a solution, several crops have been releases across the world:
- Iron – biofortification of rice, beans, cassava, legumes and sweet potato
- Zinc – biofortification of rice, beans, maize, sweet potato and wheat
- Provitamin A carotenoid – biofortification of cassava, maize, and sweet potato
- Amino acid and protein – biofortification of cassava and sorghum