Evaluation of Functional Properties of Spontaneous and Starter Culture Fermented Sweet Potato Flour

Sweet potato tubers obtained from a local market were sorted, washed processed into fermented and unfermented sweet potato flour. The samples obtained were analysed for their functional properties (swelling power, solubility index, water absorption capacity, dispersibility and bulk density) using standard laboratory procedures. A significant difference (p > 0.05) was observed in the loose and packed bulk density with values ranging from 0.488 to 0.607 g/mL and 0.701 to 0.801 g/mL respectively but there was no significant difference (p > 0.05) in the water absorption capacity, oil absorption capacity and dispersibility. There was no significant difference (p > 0.05) in the swelling power but numerically the swelling power increased with increase in temperature. A significant difference in the solubility index above 75°C and increase in solubility with increase in temperature was observed. The result of this study showed that fermentation had no significant effect on the functional properties of the sweet potato flour except its effect on the porosity of the granules as shown in the result of the bulk density. The functional properties of these flours showed their uniqueness which can be useful for food application processes.j