Stability of vitamin D3 and Zinc in fortified extruded rice during processing, storage and cooking

Food fortification for the prevention and treatment of micronutrient deficiency disorders is one of the most widely methods that because of its low cost and no need to change dietary habits was used all around the world. In grain fortification, immersion and spraying methods are usually used, and extrusion processes are used for cereal flour. In extrusion fortification method, the used extensions are into the food matrix so their output during different processing stages is less than other enrichment methods. In this study, rice reconstituted by extrusion cooking method, was enriched with vitamin D3 (100000 IU/g) at concentrations of 2.5, 5, 7.5 and 10 µg/100g and Zinc (as Zinc oxide) concentrations of 5, 10, 15 and 20 mg/100g and then remaining of Vitamin D3 and Zinc were measured before and after extrusion and before and after cooking in 30 days intervals during 180 days storage period. According to the results, storage period and also the cooking process at all initial concentrations have a significant effect (p<0.5) on Vitamin D3 and Zinc stability of extruded fortified rice so that the average content of Vitamin D3 and Zinc at the end of storage period of 180 days showed a loss of 32.9 and 11.3% (before cooking), 38.9 and 24.0% (after cooking), respectively but these materials had a good stability during the extrusion process. Overall, during the different processing stages, the average content of Vitamin D3 and Zinc showed a loss of 87.1 and 39.0%, respectively.