FORTIFIED BUT HOW MUCH? THE CHALLENGE OF MEASURING ADDED IRON IN WHEAT FLOUR

How much iron is being added to wheat flour during fortification? And how do we know if it’s enough, or too much?

This remains one of the biggest technical challenges in India’s fortification landscape. While India has clear standards from the Food Safety and Standards Authority of India (FSSAI) for iron levels in fortified wheat flour, measuring the actual added iron, not just the total iron content, is a complex process. Accurate measurement is essential to ensure both the safety and effectiveness of wheat flour fortification. 

Why measuring added iron matters

Getting the amount of added iron right matters because it directly affects health outcomes.
Iron deficiency anaemia is one of India’s most persistent public health challenges, affecting millions, particularly women and children.
When iron levels in fortified flour are too low, the intervention may fail to make an impact. Too high, and it may pose health or regulatory concerns.

Methods for detecting Iron in fortified wheat flour

There are various methods, ranging from advanced laboratory techniques to simpler field-based approaches, to help determine iron levels in fortified wheat flour.

Table 1. Methods for detecting Iron in wheat flour

Key challenges in determining added iron in wheat flour

1. Natural vs. Added Iron: A Complicated Distinction
Wheat contains natural iron. The challenge lies in accurately determining how much iron has been added during fortification. Most of the laboratory methods determine only the total iron content. When these methods are used to test fortified wheat flour, they provide the total iron content, which includes natural iron from wheat and added iron.  

2. Challenges in Sampling Fortified and Unfortified Flour
There is one way to determine the added iron content using these conventional methods. We can test fortified wheat flour samples and unfortified wheat flour samples from the same batch. Subtracting the total iron content of the unfortified sample from that of the fortified sample will give us the added iron content. But the key challenge here is that the natural iron content in wheat flour can vary from lot to lot and getting both the fortified and unfortified samples from the same lot every time is difficult. This limits the accurate estimation of the added iron content. 

3. Testing Limitations: Qualitative vs. Quantitative Methods
Although most of the laboratory methods like AAS and ICP-OES, measure only the total iron content, there is one test that can detect the added iron. It is known as the Iron Spot Test (IST). It produces red coloured spots in proportion to the added iron present in the sample. However, the problem is that counting these spots and estimating the exact amount of added iron is very difficult. Thus, we can use IST only in a qualitative manner. Colourimetric methods offer better detection of added iron and iron salt types but have sensitivity limits. Techniques like EDXRF show promise for rice but might have limitations on powdered materials like wheat flour and hence need validation. 

Figure 1. Iron Spot Test  - Unfortified and fortified atta (confirm presence of added iron)

4. Variability in Iron Fortificants
Different iron compounds used in fortification, such as ferrous sulfate, ferrous fumarate, and NaFeEDTA, interact differently with wheat flour. Some dissolve easily and are more bioavailable, while others are less soluble and harder to detect. Encapsulated iron, which prevents changes in flour colour and taste, further complicates measurement.

Inconsistencies in testing methods across different laboratories and regions lead to discrepancies in reported iron levels. Without standardised protocols, comparing results becomes difficult, making regulatory compliance more complex.

Overcoming the challenges

To make sure that fortified wheat flour meets the right amount of added iron, a reliable testing method is essential. Colourimetric methods can differentiate between iron forms and can determine added iron. Unlike expensive and complex lab instruments, colorimetric tests are affordable and portable. This makes them practical for field testing, especially in regions where access to high-end lab equipment is limited. 

Fortify Health is working on identifying and validating a method that can selectively determine added iron in fortified wheat flour. By refining analytical techniques, the organisation aims to develop an accurate and accessible testing method that differentiates between natural and added iron. This approach will improve fortification monitoring, enhance quality control, and support regulatory compliance, ensuring that fortified wheat flour delivers its intended nutritional benefits effectively.

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