Macronutrient and Mineral Composition of Selected Traditional Rice Varieties in Sri Lanka

Rice (Oryza sativa) is the staple food in Sri Lanka.Being a country rich in biodiversity, over 3000 rice varieties have been reported in the country.This study was carried out to investigate the macronutrient composition and mineral composition of selected common traditional or heirloom rice varieties which were grown from ancient times in Sri Lanka.Six heirloom red pericarp rice varieties, one heirloom white pericarp rice variety, two genetically improved white pericarp rice varieties and one genetically improved red pericarp rice variety were collected representing all the agro-climatic zones of Sri Lanka.Five hundred grams each sample was cleaned, dehusked, ground and pooled to obtain a composite sample.The prepared rice samples were analyzed for measure the moisture, crude fat, crude protein, ash and total carbohydrate contents.Mineral composition was analyzed using inductive couple plasma mass spectrophotometry (ICP-MS).The results indicated that all the rice varieties tested were significantly not different by their carbohydrate contents.Total carbohydrate contents varied from 65.80±0.79% to 79.30±0.38%.Crude fat contents of rice varieties varied from 1.59±0.01%to 2.87±0.20%,crude protein contents varied from 7.60±0.20%to 9.31±0.63%,ash contents ranged from 0.84±0.03% to 2.95±0.01%.Red pericarp rice varieties were richer in crude fat, protein, ash and minerals such as Na, Mg, K, Ca, Al, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Sn, Li, Be, V, Ga, Rb, Sr, Mo, Cd, Ba and Bi than white rice pericarp varieties.Further traditional rice varieties were richer in overall nutritional quality and in mineral composition compared to genetically improved white pericarp rice varieties.Traditional rice varieties are good sources to fulfill most of the daily mineral requirement of human.As an overall conclusion, red pericarp rice has more nutritional value than white pericarp rice.According to the results, some traditional varieties as well as red pericarp improved rice varieties are nutritionally important for human beings.