Sensory evaluation of extruded quality protein maize-based supplementary foods

Maize porridge is widely consumed by children less than five years of age in Tanzania and other countries. The aim of this study was to evaluate the sensory attributes and the overall acceptability of the extruded quality protein maize-based supplementary foods for children in Tanzania. Two ready-to-use supplementary foods were produced by extrusion cooking (quality protein maize-soybeans-common beans and quality protein maize-soybeans-cowpeas) using the following food ingredients: quality protein maize, soybeans, common beans and cowpeas. Sugar, vitamins and mineral premix were added. These products were tested against a control diet made from common maize, soybeans, millet, wheat and groundnuts. A panel of sixty consumers was involved in the evaluation of sensory attributes of the porridge samples and overall acceptability was determined using 5 point Hedonic scale. Descriptive analysis was performed by 11 trained panelists using the lexicon developed. Statistical analysis was performed using analysis of variance and principal component analysis. Consumer evaluation revealed that quality protein maize-soybeans-common beans porridge was rated higher (p˂0.05) for aroma (4.6) and taste (4.6) than all porridge samples tested. Despite higher rating in aroma and taste, all the porridges (quality protein maize-soybeans-common beans, quality protein maize-soybeans-cowpeas and conventional porridge) were equally acceptable (p˃0.05) by the test panelists. Mean scores for overall acceptability of quality protein maize-soybeans-common beans, quality protein maize-soybeans-cowpeas and conventional porridge were 4.6, 4.3 and 4.2, respectively. All the three porridges were differentiated (p˂0.05) using the identified language for quantitative descriptive study. The sensory attributes of colour, oiliness, aroma, sweetness, liking and aftertaste in principal component 1 distinguished experimental porridges from the control. However, all the food products could be described by viscosity, sweetness and colour in principal component 2. This was an indication that test diets, quality protein maize-soybeans-common beans and quality protein maize-soybeans-cowpeas resembled the control diet by some attributes namely, aroma, aftertaste and sweetness and therefore, had higher potential for acceptance by consumers.