Descriptive sensory characterization of cooked paste (<i>amala</i>) made from sweet potato flour (<i>elubo</i>)

Abstract

Describing the sensory characteristics of new or modified products is an integral part of food quality control. Sweet potato amala as an important end product could serve as an avenue for utilization of the crop, however, sensory attributes that will influence and ensure consumer acceptability need to be determined. Three varieties of sweet potato roots were processed into elubo using two methods. The elubo was prepared into amala. Sensory terms were developed for attributes of amala samples using quantitative descriptive analysis. Overall acceptability of the samples was scored on a 9-point hedonic scale. Analysis of variance was conducted on each attribute to determine significant differences among samples. Pearson’s correlation coefficient between consumer acceptability and sensory attributes of amala was computed. Twelve sensory terms were generated for attributes of appearance (smooth, greasy, oily), colour (grey, orange, brown), taste (sweet, sour), texture (grainy, sticky, thick) and odour (fermenty). Amala samples differed significantly (p < 0.001) in all the attributes except in greasy appearance and sour taste. Variety is a major factor responsible for the differences observed in the sensory attributes of sweet potato amala. Yellow-fleshed varieties and parboiling method were more suitable for elubo targeted at acceptable sweet potato amala. Acceptability of sweet potato amala is significantly (p < 0.001) correlated with grey colour (0.95), orange colour (-0.99) and grainy texture (-0.91). It is also significantly (p < 0.01) correlated with smooth appearance (0.84), brown colour (-0.70), sticky texture (0.73) and fermenty odour (0.72). Sensory attributes required for acceptable sweet potato amala are high scores for grey colour, smooth appearance, sticky and thick texture, and fermenty odour.

Keywords: Sweet potato flour, elubo, amala, sensory quality, quantitative descriptive analysis