Rice fortification has been an under-utilized opportunity. Technologies that have been used cost-effectively for nearly a century in wheat and maize milling could not be adapted to rice milling. Rice fortification is complex.
Here we highlight the main technologies available to fortify rice:
Hot extrusion passes dough made of rice flour, vitamin/mineral mix, and water through a single or twin screw extruder and cuts it into grain-like structures that resemble rice grains. This process involves relatively high temperatures (70-110°C) obtained by preconditioning and/or heat transfer through steam heated barrel jackets. It results in fully or partially pre-cooked simulated rice-like grains that have similar appearance (sheen and transparency) as regular rice kernels. The rice-premix thus developed is blended with natural polished rice at about 1:200 ratio to produce fortified rice.
Cold extrusion, also produces rice-shaped simulated grains by passing a dough made of rice flour, vitamin/mineral mix, and water through a simple pasta press. This technology does not utilize any additional thermal energy input other than the heat generated during the process itself, thus is primarily a low temperature (below 70°C), forming process resulting in grains that are uncooked, opaque, and easier to differentiate from regular rice kernels. The rice-premix thus developed is blended with natural polished rice at about 1:200 ratio to produce fortified rice.
Coating combines the vitamin/mineral mix with ingredients such as waxes and gums. The mixture is sprayed to the rice on the surface of grains in several layers to form the rice-premix and then is blended with polished rice. Manufacturers in Costa Rica, the Philippines and the United States use this process. The rice-premix thus developed is blended with natural polished rice at about 1:200 ratio to produce fortified rice.
Dusting, observed only in the U.S., involves dusting the polished rice grains with the powder form of the vitamin/mineral premix. The vitamin/mineral mix sticks to the grain surface because of electrostatic forces. Nutrients are removed through washing and therefore a remark on packages is required by law: ‘Do not rinse before or drain after cooking’.
Want to know more about rice fortification? Please review this document with the most common frequently asked questions.
Read a report: Introducting Fortified Rice in Cambodia and Vietnam
Want to understand more about rice fortification? View rice fortification in pictures on the GAIN Guardian platform here.