Physicochemical and Functional Quality of Tigernut Tubers (Cyperus esculentus) Composite Flour

Abstract

Aims: To develop composite flour from Ghana’s underutilized tigernut and evaluate its physicochemical and functional properties. Place and Duration of Study: Samples for the tigernut composite flour were obtained from the Madina market in Accra, Ghana, in May, 2014. Laboratory and data analyses were done at the Biotechnology and Nuclear Agriculture Research Institution of the Ghana Atomic Energy Commission, Accra- Ghana. Methodology: Tigernut samples were obtained and dried using a hot air oven, soy bean samples were blanched for 30 mins and dehulled before drying with a hot air oven. Soy bean for germination were socked, drained and spread on a moist cotton cloth and allowed to germinate. Maize samples were roasted in a hot air oven till they became golden brown. All samples were subsequently milled into flour using a hammer mill. Tigernut, soy bean and maize flour were mixed into composite flour in seven different percentage ratios. Physicochemical and functional qualities of tigernut tuber composite flour were analyzed using appropriate protocols. Results: There were significant differences in the physicochemical properties of all seven samples of tigernut composite flour. The highest mean value of moisture content recorded was 6.31±0.29% however it was within the acceptable range for flour. The highest mean values of total ash, pH and protein content recorded were 2.47±0.08%, 6.57±0.01 and 11.37±0.02% respectively. The functional properties had TMS1 recording the highest water absorption capacity mean value of 14.33±0.58% and TMS6 recording the highest bulk density and swelling power mean values of  0.86±0.03 g/cm3 and 5.40±0.14 g/g respectively. TMS4 recorded the highest solubility index mean values 27.00±2.00%. Conclusion: Different percentage combination of tigernut, soy bean and maize significantly affect the physicochemical and functional properties of its composite flour. Utilization of tigernut in product development can cater for its underutilization and hence reduce its post harvest loses. Further work is however needed to establish its nutritional quality and shelf stability to determine the appropriate percentage combination.