Rice Grains Iron Density Improvement in Thailand

Rice Grains Iron Density

               Compared to other cereal, iron density in rice grains is considered low.  The recommended daily allowance (RDA) of iron for Thais is approximately 15 mg.  At the 200-250 gm of polished rice consumed daily, it is estimated that the optimum iron density in the whole rice grains should be close to 5 mg/100 g in order to supply one third of the RDA.  

               This number seems to be unreachable as compared to 1.3-1.5 mg/100 gm among popular rice cultivars.  To step up the breeding activities, the extensive survey of iron density among landraces identified potential donors of high iron density.  The majority of these high iron rice lines belong to the black purple rice. The major limitation to using these rice germplasm is high polyphenol and phytic acid contents in the rice bran. Because white color rice is low in polyphenol and phytic acid, attempts were made to hybridize white x purple rice parents to transmit high iron density to normal white rice. 

                “The first successful white rice contains 2.1 mg /100 g as the whole grain.  This advanced line coded as 313-19-1-1 is aromatic with intermediate amylose content. From crosses between upland rice, Kum Doi Chang (KDC) and Hom Pamah, we successfully identified white color rice with 2.8 mg/100 g of grain iron.  The highest iron density lines were identified as progenies from the hybridization between a wild rice, O. nivara and high iron rice Jao Hom Nin (JHN).  One of the highest iron dense rice contained up to 5 mg/100 g.  Our emphasis is now directed to improving iron bioavailability.” Rice Science Center (RSC): Thailand