Colour Profile, Pasting and Sensory Properties of Processed Sweet Potato Flour

ABSTRACT

In this study, sweet potato was purchased and processed using different methods to obtain 4 different sweet potato flour samples. Sample A was unfermented sweet potato flour, sample B was fermented spontaneously, while sample C and D were produced by fermentation using indigenous starter cultures of lactic acid bacteria and yeast for 48 h and 72 h respectively. Colour profile, Pasting and Sensory evaluation was conducted. The whiteness (L* value) obtained in this study is within the range of value (87.29-89.52), Also, the redness value (a*) and yellowness value (b*) of the sweet potato flour samples also showed a significant difference (p<0.05). Sample a had a higher value when compared with samples B,C and D. Pasting properties such as peak viscosity, trough viscosity, breakdown viscosity, setback, pasting temperature were determined. It was noticed that fermentation process and increase in fermentation time significantly (p<0.05) decrease the peak viscosity in this research work and all samples had a higher cooled paste viscosity than their corresponding hot paste viscosity. Nevertheless, sensory evaluation was carried out using thet 9-point hedonic scale, samples A,B,C,D are significantly different (P < 0.05).