Effect of cooking methods on the stability of thiamin and folic acid in fortified rice

Abstract

Rice fortification offers great potential to deliver essential micronutrients to a large part of the world population. However, high temperatures required for cooking rice are deleterious to thermally labile micronutrients. This study evaluated the content and stability of thiamin and folic acid in fortified rice after different cooking methods (stir-frying, boiling, cooking in a microwave oven and boiling in a Food Service). The analyses were performed by High Performance Liquid Chromatography (HPLC). The fortified rice showed the highest thiamin content (0.97 mg/kg) and retention (65.4%) when cooked in microwave oven, and for folic acid the lowest content (0.17 mg/kg) and the highest retention (96.11%) when cooked in a Food Service and stir-fried, respectively. In conclusion, the stability of thiamin and folic acid varied according to the cooking method and the stability of folic acid presented higher percentages in relation to thiamin in the different methods.