Effect on Quality and Appearance

As a guiding principle it is essential that the fortification of wheat flour and maize meal will not change consumer acceptability of the fortified food. It would be ideal for the fortification to be invisible to the consumer. That is, there would be no detectable difference in the appearance, sensory properties or even the price of the fortified product, but this is not always achievable.

Colour and Appearance

The visual appearance of any food is the first of the organoleptic senses that a consumer experiences. Therefore if the fortified food has had any changes in colour and appearance the consumer is more likely to reject the product. At the current fortification levels normally found in wheat and maize there is no adverse impact on colour or appearance. Elemental iron powders may cause a slight darkening of flour, while high levels of riboflavin and folic acid can cause a slight yellowing, but these changes are accepted once all flour is similarly treated. Ferrous sulphate does not cause any colour problems in the dry flour/meal but could lead to off-colours in cooked maize products.

Flavour and Aroma

The same criteria for colour and appearance apply for flavour and aroma. The consumer must not be able to detect a discernable difference. Any detectable change in flavour and aroma caused by fortification is unacceptable.

Shelf Life

As a general rule of thumb the addition of micronutrients to produce a fortified flour of wheat or maize must not reduce the normal or expected shelf life of the flour. Any reduction of shelf life will result in lost products and reduced consumer acceptance of the food. Reduced shelf life is usually due to the development of rancidity in the flour caused by soluble iron and zinc salts. This is particularly true for high extraction and whole grain flours.

Taste and Mouthfeel

There must be no change in product texture and mouthfeel. Rancidity will affect the taste and mouthfeel as well as aroma and flavour of both the flour and the finished products as consumed. Rancid products have a slightly soapy mouthfeel and a distinctive unpleasant odour.

Sensory Testing

There has been extensive testing and experience to show that fortification can be accomplished without adversely affecting any of these sensory properties in standard products such as flour, maize meal, bread, cakes, instant noodles and pasta. However, there are some cereal-based foods unique to different regions of the world that have not been tested. These should be tested prior to starting a general fortification program.