Evaluation of the Physico-Chemical Characteristics and Nutritional Performance of Sweet Potato (Ipomea batatas) and Yam (Dioscorea cayenensis-Rotundata Complex) Flours Sold on the Korhogo Market Used in the Formulation of Compound Breads

Sweet potato (Ipomea batatas) and “kponan” yam (Dioscorea cayenensis-rotundata complex) produced in the city of Korhogo are defined as staple foods. However, post-harvest conservation of these tubers is a major problem. This present work aims to enhance the value of sweet potato and yam tubers through the characterization of the physicochemical and functional potential of their flours and to carry out incorporation tests in the formulation of compound breads. Methods used are firstly the production of flours through three types of drying: drying in an oven at 60°C for 48 hours, drying in the shade for 7 days and solar drying for 4 days. Dry samples are ground to obtain flours. Secondly, the characterization of flours according to the physicochemical parameters by determining humidity, pH, titratable acidity, protein levels, lipid levels, carbohydrate levels, fiber levels, ash levels and calculating energy values. Functional parameters to be determined are the apparent density, swelling power, solubility index, water absorption capacity and oil absorption capacity of each flour. And finally the production of breads composed of different rates of incorporation of these flours in wheat flour in the order of 10%. Results showed that the flours with the good characteristics are those resulting from oven drying with a pH of 5.31 ± 0.34 for potato and 5.29 ± 0.03 for yam. Moisture levels are 7.33 ± 1.15% for sweet potato and 6% for yam. Protein levels are 2.73 ± 0.04% for sweet potato and 4.67 ± 0.06% for yam. Carbohydrate levels are (82.99 ± 0.11%) for sweet potato and (80.24 ± 0.64%) for yam. These flours from oven drying have the best incorporation rates which are 20%. From this study, we retain through the analysis of the parameters that sweet potato and yam flours have essential characteristics for human nutrition. Incorporating sweet potato or yam flour into wheat flour not only makes these tubers available but also adds value to the diet and contributes to a balanced diet.