Preparation of boiled potato
Cleaned whole sweet potatoes (3–4 in number) were put in a
saucepan containing about 500 ml of boiled water (sufficient to
immerse the potatoes) containing 1.5% fresh-squeezed lemon juice
(to prevent oxidation), and boiled until the potatoes were almost
edible. Water was drained off and the potatoes were kept at room
temperature. The weight of the potatoes was recorded to calculate
nutrient content under raw and boiled conditions. The boiled potatoes
were then peeled to remove the skin, and cut into large
chunks (5–7.5 cm) using a knife.