Glycemic index is defined as the incremental area under the blood glucose response curve of a 50 g carbohydrate portion of a test food expressed as a percent of the response to the same amount of carbohydrate from a standard food taken by the same subject. This study investigated glycemic index of maize stiff porridges consumed as staple food in Malawi and a large majority of other countries in sub-Saharan Africa to identify areas for improvement in consumer diets. Stiff porridges were prepared using flour from whole maize, maize grits, and fermented maize grits. The porridges were served to 11 healthy volunteers for 3 weeks, with two serving sessions a week. Glucose was served as a reference food during weekly serving sessions. Results from descriptive analysis revealed that glycemic responses varied across subjects and porridge types. Porridge prepared from fermented maize grits had moderate glycemic index of 65.49 and was comparable in nutrient composition and sensory characteristics with the other test porridges. Glycemic indices of the porridges prepared from whole maize flour and grits were high at 94.06 and 109.64, respectively, attributed to the effect of traditional maize flour processing, preparation, and cooking methods used. The study also calculated glyaemic load of the porridges and drew recommendations to inform diet planning and modifications for healthy and diabetic individuals.
Keywords: Consumer behavior; diabetes mellitus; diet; fermentation; ugali.