Process Development for Quadruple Fortification of Salt

This process was developed to simultaneously deliver iron, iodine, folic acid, and vitamin B12 for holistic prevention of anaemia and other risk factors for prenatal complications in vulnerable populations. Salt was chosen as the ‘vehicle’ for the micronutrients because ‘doses’ of the micronutrients can be predicted. The process was based on a cold forming extrusion-based microencapsulation (for making premix) that ensures that added micronutrients are stable, indistinguishably mixed with salt, do not segregate, and do not cause changes to the sensory characteristics of salt and foods. The dusting of the micronutrient premix with titanium dioxide masked its brown colour while its coating with soy stearin prevented the adverse moisture aided interaction between iron and iodine. The hydrophobic nature and the initial amount of soy stearin used for coating caused the micronutrient premix to float; contamination of TiO2 due to its recycling caused dark spots on the surface premix. Double coating with 5% hydroxypropyl methylcellulose and 5% soy stearin solved the floating problem; coating with a mixture of 15% TiO2 and 10% soy stearin solved both problems. The required pH (≥ 8) for full dissociation of folic acid, its solubility, and stability caused vitamin B12 instability; hence, both micronutrients cannot be added to salt through a solution. In salt, they were lost through oxidative degradation. The coextrusion of folic acid and vitamin B12 with ferrous fumarate (a reducing agent) minimized the oxidative degradation of the micronutrients. The colour masking and coating of the premix ensured that the micronutrients did not affect the colour of the salt. Also, the coextrusion prevented the micronutrients from photodegradation. The salt samples can deliver 50-200% recommended dietary allowances of the micronutrients based on the consumption of 10g of salt per day. The micronutrients were very stable in the salt and met the set target (70% retention after 6-month storage). Over 85% of the micronutrients were retained in salt after 6-month storage, even at 45 oC/60-70% RH. The micronutrients were stable in cooking and did not cause any changes to the sensory properties of the salt or food.Ph.D