Better wheat, better flour - CIMMYT 2022 Annual Report

Two recent efforts at CIMMYT aim to improve the quality of bread wheat. A new genetic assay will bring down the cost and increase the speed of identifying more nutritious wheat varieties, to reduce dietary deficiencies of iron and zinc, and to improve the nutrition of children globally. Blending flours made from wheat and from other crops will allow African countries to produce more food with less imported grain.

Two lines of work at CIMMYT promise to improve the quality of wheat, and the availability of flour.

Iron and zinc are essential micronutrients, which can be supplied from wheat, whether it is imported or grown domestically. Children fail to develop properly if their diet lacks these minerals. Increasing the iron and zinc content in the world’s wheat supply would be a boon to global nutrition.

Conventional plant breeding can create wheat varieties that are rich in iron and zinc, but these efforts are hampered by naturally-occurring, high levels of phytic acid in some wheat varieties. Phytic acid binds to iron and zinc, preventing them from being absorbed in the human digestive tract.

The solution is to select for wheat varieties that are low in phytic acid, and high in iron and zinc. However with prevailing technology, such breeding can take several years.

A recent three-year study by CIMMYT and partners, led by Zhengyu Wen, and published in Frontiers in Plant Science, has found a way to quickly assay for phytic acid, by determining the amount of phosphate released after treatment with a commercially available enzyme. Genetic markers were found on five wheat chromosomes, making it possible to select for the target genes early in the breeding program, to reduce the content of phytic acid. According to Maria Itria Ibba, a CIMMYT scientist who participated in the study, “This protocol is based on the same principle as the one for a certain commercially available assay. But unlike that one, our protocol does not require that researchers buy a kit. This new protocol greatly reduces the cost of the analysis, which should make it easier to use in low and middle-income countries. It will also speed up the breeding of high-yielding, nutritious wheat varieties.”

Wheat quality can be enhanced genetically, or in the flour mill.

Other work at CIMMYT is showing how the dependency on wheat imports can be reduced by blending flours from wheat and from other crops. In East Africa, wheat growers have not been able to keep pace with the spiraling demand for flour to make bread, chapatis, biscuits, and even pizza, while millers must compensate for the reduced availability of imports from Russia and Ukraine. In Nairobi, one bakery alone uses 15,000 tons of flour every month. Since the 1980s, Kenya’s wheat harvest has stagnated at about 200,000 tons per year. Only 10% of the country’s wheat supply is produced domestically, while the Russian invasion of Ukraine has choked supplies and raised costs of imported wheat.

“To make blended flours a commercial reality, we will need policies that stimulate the production and marketing of alternative crops and their use in flour production,” explains CIMMYT’s Global Wheat Program director, Alison Bentley. “Millers may have to invest in new equipment. We will also need research that ensures availability to meet milling demands and understanding of the functional properties of new blended flours. Marketing research will be important to introduce consumers to the new flour blends, and to ensure demand for the baked goods.”

Wheat may be getting more expensive, but it is still available on the global market at a consistent quality. Substitute crops, grown nationally, may not be available in the amounts and quality needed. Boosting their supply will require investments in production and marketing, as well as partnerships with smallholder producers and other actors on the food and seed value chains.

Blending wheat flour with milled cassava, sorghum or millet has been proposed as a viable solution which could reduce wheat imports while creating more demand for traditional crops such as sorghum and millet, which can adapt to climate change.

Thanks to its white color, cassava flour is an attractive solution for flour millers. However, in Nigeria, cassava flour was unpopular, partly because of few policy incentives, but also because wheat was cheap, until recently. Millet is a healthy food, and this hardy plant performs well in East and West Africa. Millers and bakers in Africa would use more millet if the grain was always free of stones and other impurities and if the cost of millet was lower. White sorghum is another option to blend with wheat flour. It could be used for 15% of the flour in bread, and 20% in biscuits.

Maria Itria Ibba

Head of the Wheat Quality Laboratory and Cereal chemist

This protocol is based on the same principle as the one for a certain commercially available assay. But unlike that one, our protocol does not require that researchers buy a kit. This new protocol greatly reduces the cost of the analysis, which should make it easier to use in low and middle-income countries. It will also speed up the breeding of high-yielding, nutritious wheat varieties.

Increasing the iron and zinc content in the world’s wheat supply would be a boon to global nutrition.

In Nairobi, one bakery alone uses 15,000 tons of flour every month.

Millers and bakers in Africa would use more millet if the grain was always free of stones and other impurities and if the cost of millet was lower.