Protein, carbohydrate and fibre in cereals from Mali - How to fit the results in a food compostion table and database

During the past 5 years, the main staple foods (cereals) used in Mali have been collected to develop a food composition table and database. We present recent results of protein, carbohydrate and fibre content for some cereals. Samples were collected from five different regions. To reduce laboratory costs, composite samples (cs) were made. The cereals analysed were sorghum (Sorghum bicolor) (cs = 142), millet (Pennisetum glaucum) (cs = 163), maize (Zea mays) (cs = 107), wheat (Triticum aestivum) (cs = 123), rice (Oryza sativa) (cs = 151) and fonio (Digitaria exilis) (cs = 104). Fonio is an old cereal cultivated across the dry savannahs in West Africa, and is very popular in Mali. All samples were cleaned and processed (ready to cook) before analysis. Detailed sampling plans were used. For total nitrogen, Kjeldahl and Dumas combustion methods were used. Methods used for carbohydrate (sugar and starch) were polarimetric, spectrophotometric and HPLC, and a gravimetric method was used for fibre. The mean±S.D. content of protein for 100 g cereal was: in millet 7.9 ± 1.4 g, sorghum 10.3 ± 0.7 g, maize 7.6 + 1.1 g, rice 6.3 + 0.3 g, wheat 10.6 ± 1.1 g and fonio 7.2 ± 0.4 g. The mean ± S.D. content of carbohydrate and fibre per 100 g cereal was: in millet 65.8±10.1 and 6.2±2.3g, sorghum 73.5±4.3 and 4.7±0.1 g, maize 73.0±10.2 and 4.6 ± 1.3 g, rice 83.7 ± 7.8 and 1.1 ± 0.0 g, wheat 75.1 ± 1.8 and 3.0 ± 0.0 g and fonio 74.3 ± 0.1 and 2.2 ± 0.3 a, respectively. As indicated by the standard deviations there were considerable geographical differences in nutrient content for the same cereal. There is no apparent explanation for these differences. Until this is explored further, it is necessary to develop separate tables for different regions. © 2004 Elsevier Ltd. All rights reserved.