EFFECT OF PRE-TREATMENT METHODS ON QUALITY OF SWEET POTATO FLOUR

ABSTRACT Effect of pre-treatment methods on quality of sweet potato flour was investigated. Fermentation and blanching were used for the pretreatment of sweetpotato and coded sample SF72 (sample fermented for 72 h), sample SF48 (sample fermented for 48 h), sample SB10 (sample blanched for 10 min) and sample SB05 (sample blanched for 5 min). The samples were analyzed on nutritional and chemical properties. Selected mineral content shows that calcium content ranged 165.90 to 184.64 mg/100g, manganese ranged 31.18 to 42.18 mg/100g, potassium ranged 386.86 to 444.92 mg/100g, phosphorus ranged 77.33 to 105.75mg/100g, zinc ranged 3.60 to 6.59 mg/100g and iron content ranged 9.13 to 9.63 mg/100g. Functional properties shows that bulk density ranged 0.52 and 0.60 mg/100g, water asorption capacity ranged 4.92 to 5.85%, oil absorption capacity ranged 1.74 to 1.95%, emulsion capacity ranged 15.39 to 27.47 %, emulsion stability 31.45 to 38.39%, foam capacity ranged 4.22 to 6.05%, foaming stability ranged 3.63 to 5.23%, swelling capacity ranged 0.61 to 0.71%, swelling index ranged 0.62 to 0.82%, dispersibility ranged 72.00 to 78.50 % and gelatinization temperature ranged 65.50 to 78.100C. Carbohydrate content ranged 80.64 to 88.06 % and starch ranged 68.79 to 78.66%. Pasting properties shows that peak viscosity ranged 145.21 to 284.51 RVU, trough ranged 122.81 to 175.10RVU, breakdown ranged 25.91 to 111.91RVU, final viscosity ranged 24.88 to 224.31RVU, setback ranged 67.11 to 86.61RVU, peak time ranged 5.51 to 6.21 min and pasting temperature ranged 73.34 to 86.88 °C. The results shows the nutritional and chemical properties of sweetpotato flour treated with blanching and fermentation.