Thirty-eight rice varieties, grown in Low Country Wet Zone, during Yala (2006) and Maha (2006Maha ( ⁄ 2007 seasons were screened for stable high iron rice varieties and were statistically analysed. Iron contents ranged 1.89-3.73 mg 100 g )1 and varied significantly (P < 0.05) with variety and season. Selected fifteen high iron rice varieties, at degree of polishing 8-10% were analysed for iron, zinc and phytate. High iron contents in endosperm were observed in Suduru Samba (0.47 mg 100 g )1 ), Basmati 370 (0.37 mg 100 g )1 ), Kalu Heenati (0.42 mg 100 g )1 ), Rathu Heenati (0.44 mg 100 g )1 ) and Sudu Heenati (0.37 mg 100 g )1 ). Phytate contents of polished rice varieties ranged from 200-300 mg 100 g )1 . Large reduction in iron content (84.5-93.6%) was observed in polished rice while the reduction in phytate content (18.9-40.8%) was low. Percentage dialyzability of iron in selected endosperm high iron rice varieties ranged from 1.73 to 8.71. Dialysability of iron in cooked polished rice did not show a relation to the phytate content in raw rice.

Abstract:Rice is the staple food in Sri Lanka and the country has a large number of traditional and improved rice varieties. Since their zinc content and bio-availability has not been studied systematically, the present study focused on the zinc content in some traditional rice varieties with high demand and also some improved rice varieties, and their predictable bioavailability.Thirty nine rice varieties from Bombuwala and Bathalagoda Regional Agricultural Research and Development Centres, grown during Yala (March -August, 2006) and Maha were analysed for stable high zinc rice varieties. Mean zinc content (mg/100 g, on dry weight basis) in the varieties from Bathalagoda varied from 2.17 (Masuran) to 4.49 (Wanni Dahanala), while in the varieties from Bombuwala it varied from 2.46 (Bg 352) to 3.71 (Dahanala) with average values of 3.19 ± 0.55 and 3.11 ± 0.32, respectively. Overall mean zinc content (mg/ 100 g, on dry basis) in the two locations varied from 2.51 (Masuran) -3.91 (Kalu Bala Wee) with an average value of 3.18 ± 0.45.was observed with respect to the site, season, variety, site*var and ses*var in two way ANOVA, while site*ses*var in three way ANOVA. The reduction of zinc and phytic acid contents in the polished rice varieties (at polishing rate 8 -10 %) were 18.2 -60.7 % and 18.8 -40.8 %, respectively between zinc and phytic acid. A moderate bio-availability of zinc was shown by the molecular ratio of zinc:phytic acid and these values ranged from 8.3 -12.5 and 9.3 -18.9 in brown rice and polished rice, respectively.