## 2 Materials and Methods
### Laboratory Analysis  
#### 2.2.1 Biochemical Composition  
The biochemical analysis of the samples was carried out using standard analytical methods; the dry matter content of fresh yam tubers was determined using the standard operating protocol developed in the RTBfoods project method [19], where about 10 g of the homogenized yam tuber was weighed into a precleaned aluminum cup and placed in an air-conventional oven for 16 h at 105 \({}^{\circ}\)C until a constant weight was obtained. Dry matter was estimated as the constant weight difference before and after drying. Protein, crude fiber, and fat contents were determined using Official Methods 976.05, 945.45, and 950.46, respectively [20]. In the method, protein content was determined by the Kjeldahl method using the Kjeltec(tm) model 2300 operated as described in the FOSS Manual (FOSS, 2003). The sample was digested at 420 \({}^{\circ}\)C for 1 h to extract organically bound nitrogen in the form of ammonium sulfate. The digest, in the form of ammonium sulfate, was distilled into a boric acid receiver solution before being titrated with standard hydrochloric acid. A conversion factor of 6.25 was employed to convert total nitrogen to a percentage of crude protein. Starch and Soluble Sugar Content  
Starch content was determined colorimetrically using the method reported by [21], where about 20 mg of the yam sample was weighed into a clean centrifuge tube, followed by adding 1 mL ethanol, 2 mL distilled water, and 10 mL boiling ethanol. The mixture was vortexed and then centrifuged at 2000 rpm for 10 min. Perchloric acids hydrolyzed the residue to estimate the starch concentration, and the supernatant was utilized for the sugar content. Color development was achieved using the phenol-sulphuric acid reagent. A glucose standard calibration curve was developed for the quantification, and the absorbance was measured at 490 nm with a Genesys 101S UV-Vis Spectrophotometer using the following equations:  
\[\% Sugar=\frac{(A-1)\times Dilution\ factor\times Volume\times 100}{B\times Sample\ Weight \times 106} \tag{1}\]  
\[\% Starch=\frac{(A-1)\times Dilution\ factor\times Volume\times 100}{B\times Sample \ Weight\times 106}\ \times 0.9 \tag{2}\]  
Amylose content was evaluated using the iodine binding method described by [22]. About 0.1 g of the yam sample was weighed into a 100 L conical flask and dissolved in 1 mL of 95% ethanol. In total, 9 mL of 1 N NaOH was used to hydrolyze the starch. The flask was placed in a water bath and allowed to boil for 10 min before being filled with distilled water to the desired volume of 100 mL. Next, 5 mL was transferred from the 100 mL flask to another conical flask, 1 mL of acetic acid was pipettted into the tube, and a 2 mL iodinesolution was added for color development. Amylose standard from potato starch was used to develop a standard quantification curve. Distilled water was added to make up the volume to 100 mL, and the absorbance was read at 620 nm on the Genesys 101S UV-Vis Spectrophotometer (Waltham, MA, USA). 2.2 Sensory Texture Profile Analysis and Cooking (WAb, Cooking Time) Test Water Absorption (WAb) and Cooking Time (CT)  
An analysis of the WAb and CT of the boiled yam samples was carried out using the RTB foods Project Standard Operating Procedure [23] with a few adjustments. We cut off 1/10 cm from the proximal and distal ends before collecting a cuboid-shaped yam from each proximal, middle, and distal cross section. The small cuboid shape was collected using a modified stainless steel plunger measuring 6 by 3 cm (Figure 1). Six cuboid-shaped yam pieces were evaluated for each genotype. The sample's weight was taken before and after cooking in a fixed volume of water. The weight difference was taken as the amount of water absorbed. The time taken for each genotype to cook (soften and be able to be pierced through with a fork) was also noted as the cooking time. Instrumental Texture Profile Analysis of Boiled Yam  
The boiled yam samples were evaluated for textural attributes using the texturometer.