Dry matter content
Tubers were washed, sliced into small dices, and homogenized using a mixer (Kenwood FP 180, New Line, Havant, England). Ten-g of pulp was transferred to a Petri dish and preheated in an oven (Memmert ULM 400, Germany) at 60°C for 15 hrs and then at 105°C for 3 hrs (Winiger and Ludwig, 1974).
Potassium (K), magnesium (Mg), and manganese (Mn)