Differences in micronutrients content found in cereals from various parts of Mali

Food samples were collected from four different regions (Mopti, Ségou, Timbuktu and Bamako) in Mali. The cereals, analyzed for iron, zinc, thiamine, riboflavin and niacin, were millet (Pennisetum glaucum), sorghum (Sorghum bicolor), rice (Oryza sativa), wheat (Triticum aestivum) and fonio (Digitaria exilis). For millet the lowest coefficient of variation (CV %) between the regions was found in thiamine (15%) and the highest variation in niacin (126%). For sorghum it was the same nutrients that gave the lowest and highest CV, 34% in thiamine and 98% in niacin. For rice, however, the main variations were for zinc (lowest, CV 20%) and iron (highest, 141%). For wheat the lowest CV was in thiamine (47%) and highest in iron (115%), while for fonio the lowest CV was in zinc (9%) and highest in iron (61%). Even though the variation was very high for all nutrients except zinc in fonio, it was thiamine and zinc that differed the least and iron and niacin that differed the most. The use of different methods and laboratories could not explain the variation between different regions. The variation between ecological zones seems rather important. This raises the question of whether we can defend borrowing data on food composition from one country or area to another, with different ecological and climatic conditions. The globalization process impacting all countries actualize this question even more than before. Finally this has consequences for the design and use of the food composition table for Mali, which contain one main table giving average values, and separated tables from each region giving regional data when they are available.