Influence of Boiling on the Physicochemical Properties of Tubers of <i>Diocorea Cayenensis-rotundata</i> Complex “<i>Kponan</i>” Variety

Yam belong to the Dioscoreaceae family and the Diocorea genus. They are grown for their edible tuber, which is rich in starch and minerals, but low in protein and fat. In Côte d'Ivoire, the “Kponan” variety is particularly popular. Before consumption, the tubers are generally peeled, cut into pieces and cooked. However, when cooked in water, yams lose some of their nutrients. In this context, our study was conducted to assess the impact of cooking on the physical-chemical composition of the “Kponan” variety. The freshly harvested tubers were divided into two parts. The first part was used to prepare raw tuber flour, while the second part was cooked for 30 minutes. The results show a significant reduction in starch (from 70.83 ± 1.41 to 53.65 ± 1.24 %), protein (from 3.53 ± 0.14 to 1.18 ± 0.09 %), fibre (from 2.69 ± 0.05 to 1.81 ± 0.03 %) and energy (from 400.03 ± 1.94 to 388.86 ± 2.54 kcal) content in the cooked tuber compared with the control. Macro and micro-element content also fell. On the other hand, water content (from 4.28 ± 0.13 to 6.76 ± 0.04%), reducing sugars and total sugars increased during cooking. However, lipid and carbohydrate contents were not affected by the cooking process. To compensate for these cooking-related nutrient losses, it is recommended that meat, fish, oils and vegetables be added to the consumption of tubers of the “Kponan” variety.