Determination of proximate composition, energy and glycemic index values of stiff porridge prepared from composite flours

Abstract

Background : The glycemic index (GI) measures how fast or slow the blood sugar rises after the consumption of a food rich in carbohydrates. The prevalence of diabetes in Kenya is about 3% of adults. Among the regimens of type 2 diabetes mellitus (T2DM) is glycemic control using diet, although only a few diabetic persons (7%) practice it due to limited data on the GI of local foods such as stiff porridge (ugali) which is among the chief staple foods in Kenya. This study determined the proximate composition, energy and GI values of ugali from blends of cassava-millet, cassava-sorghum, cassava-millet-sorghum, whole maize-millet and maize-sorghum flour.

Methods : Ugali was prepared in the ratio of 3:5 (w/v), flour to water. Proximate composition was determined using the Association of Official Analytical Chemists methods. Carbohydrate content was determined by difference (100-moisture+fat+protein+ash+fiber content). Energy values were determined using the Atwater method. The GI was determined based on Brouns' recommendation.

Results : The moisture content, fat and protein content of maize-millet ugali was the highest at 67.5%, 5.7% and 9% respectively. Cassava ugali had the lowest fat (0.7%) and protein (1.2%). Cassava-millet ugali had the highest ash (3.1%) and fiber (11.5%) content whereas cassava-sorghum-millet ugali had the lowest ash (1.7%) and fiber (1.3%). Cassava ugali had the highest carbohydrate content (92.9%) whereas maize-sorghum ugali was the lowest (76.9%). Maize-millet ugali had the highest energy content (422.1 Kcal) while cassava ugali was the least (394.2 Kcal). Ugali from cassava-sorghum, cassava-millet, maize-millet, maize-sorghum and cassava-sorghum-millet flour recorded a GI of 46, 45, 47, 45 and 57 respectively.

Conclusion : Cassava-sorghum, cassava-millet, maize- millet and maize-sorghum ugali have low GI and thus can be recommended in the management and prevention of T2DM.