When a country chooses to fortify cereal grains, it must decide what vitamins and minerals to include. It must also determine the levels of each nutrient to add. The results of these decisions are the basis for the country’s fortification standard.
Six factors to consider in setting country standards are:
- Consumption: If consumption is high, lower amounts of nutrients are needed per kilogram of grain to create a positive health outcome. If consumption is low, higher levels are needed.
- Type of flour: High extraction flour (greater than 80%) is also known as whole wheat flour or atta flour. High extraction flour retains high levels of wheat’s natural phytates which inhibit the body’s ability to absorb iron and zinc. Consequently only the highly bioavailable sodium iron EDTA (NaFeEDTA) is recommended for high extraction flour. Also, the amount of zinc added to high extraction flour should be higher than the amount used for low extraction flour.
- Type of iron: The iron compounds recommended for wheat and maize flour fortification include ferrous sulfate, ferrous fumarate, and sodium iron EDTA (NaFeEDTA). Electrolytic iron is only recommended if flour availability is more than 150 grams per person per day. The iron compounds have different levels of bioavailability to consumers and different costs for millers. Ferric pyrophyosphate is the iron compound most frequently used with rice fortification.
- Other food fortification: If other foods are effectively fortified and they reach the majority of the population, the nutrient may be left out of grains. For example, vitamin A is often added to vegetable oils or margin and not added to flour.
- Range: Effective standards specify a minimum and maximum level of each vitamin and mineral to use in fortification. This provides a level that can be expected to have a health impact while allowing some margin so that implementation is practical. Millers rarely exceed the maximum because it would be costly to do so.
- Sensory outcomes: Global recommendations for fortification are based on levels that will not affect the product's taste, smell, or appearance. If your country is considering a standard that exceeds the global recommendations, cooking trials may be needed to ensure that the fortification does not have a negative impact on the final food product.
Some people fear that iron could cause sensory problems at the levels recommended if flour consumption is less than 150 grams per capita per day. However a study of 15 kinds of noodles and breads commonly eaten in Asia showed that the foods would be acceptable to consumers if the food were made with fortified flour. The study included foods fortified with recommended iron levels for groups that eat less than 150 grams per capita per day.
A series of baking trials in Kenya, South Africa, and Tanzania showed that wheat flour and maize meal fortified using global guidelines caused no changes in the baking or cooking properties. Participants could not consistently perceive differences between fortified and unfortified products.
Muehlenchemie conducted tests to determine how different forms of iron affect the color of pasta. The company also analyzed the cooking water of the pasta with soluble iron forms. The results showed a loss 5% of iron in non-enriched pasta (natural value), a loss of 7% in enriched pasta with fumarate and sulfate, and a loss of 40% in EDTA-enriched pasta.
Global recommendations provide information on iron, folic acid, vitamin B12, vitamin A, and zinc levels for fortification. Regional recommendations may be available for fortification with thiamin, riboflavin, and niacin which are other B vitamins frequently added to flour. Also see a guide to setting fortification levels.
The minimal amount to restore the nutrients that were in wheat naturally but lost in the milling process are:
- Thiamin (vitamin B1): 6.4 parts per million (ppm)
- Riboflavin (vitamin B2): 4.0 parts per million (ppm)
- Niacin (vitamin B3): 53 parts per million (ppm)
Note: Parts per million equals milligrams per kilogram.
For more information:
- Legislative frameworks for corn flour and maize meal fortification
- Presentation on fortifying with B vitamins, calcium, and magnesium.
- European Union guidelines and regulations in EU Reg. 1925:2006 and EU Reg. 1170/2009.
- Summaries of two workshops leading to the current global guidelines: Atlanta in 2008 and Mexico in 2004.
- Sample legislation and standards from several countries.
Food and Nutrition Bulletin
Kenya workshop participants conduct taste tests for bread that has been made with different iron compounds according to World Health Organization recommendations. Photo by Sarah Zimmerman