Physico-chemical properties and sensory quality of cassava-cowpea-millet composite flours

Abstract

There is global increase in demand for good health and nutrition. The objective of this study was to formulate nutritious composite flours from cassava (Manihot esculenta L.) roots, cowpea (Vigna unguiculata) leaves, and millet (Pennisetum glaucum), especially for children and expectant women. A Nutrisurvey software was used to formulate three flour products, namely 20:50:30, 10:50:40 and 15:60:25 of cassava roots, cowpea leaves, and millet, respectively to achieve more than 40% daily requirement of protein, iron and zinc for the expectant woman. The products were subjected to a sensory panel and evaluated against a standard commercial flour (Famila) sold in the Kenyan market. The flours were also subjected to accelerated shelf-life study based on physico-chemical properties and growth of yeast and molds. Results indicated that 20:50:30 and 10:50:40 had the highest colour scores on a 7-point hedonic scale, 5.2±1.35 and 5.2±1.48 (P<0.05). The score indicates a near equal acceptability of the flour based on colour for both the standard. The green porridge (15:60:25) was the least accepted flour and had the highest total aerobic count of 3.7 log cfu g-1 after four months of storage. The acid value of the flours ranged from as low as 1.84±0.01mg KOH g-1 for the 20:50:30 at day zero and as high as 12.9±1.73 mg KOH g-1 after six months of storage. The formulated 20:50:30 flours had protein (8.0%), fat (3.5%) carbohydrates (70%), zinc (0.6 mg100 g-1), iron (0.6 mg100g-1) and vitamin C (0.3 mg100 g-1).