Iron Retention on Flour Gel-Coated Rice Grains and Its Storage Stability

This study was conducted to determine the feasibility of iron fortification in rice grains by using rice flour gel as the coating polymer. Three iron compounds were used: ferrous sulfate (FS), ferric pyrophosphate (FP) and iron glycine (IG). After rinsing and steaming the rice (using 100 g of rice per 125 mL of water), the Khao Dawk Mali (KDML) 105 rice retained 96.82% of its iron content while Khum Doi Saket (KDSK), a dark red glutinous variety and which was presoaked for 6 h in water, lost 29% of its iron content. During a 9-month storage, the progressive percentage of peroxide values (POVs) of KDML 105 rice was higher than those of KDSK; FS catalyzed autoxidation at the fastest rate than FP and IG. FS increased POV in the enriched KDML 105 and KDSK rice at 11.6 and 2.1 meq oxygen/kg, respectively.