This study aimed at determining the best cooking method which preserves the β-carotene and vitamin C in plantain; variety Big Ebanga (unripe and ripe) and sweet potato, varieties TIb1 (dark yellow flesh) and 1112 (yellow flesh). These nutrients were analysed in raw, steamed, roasted and fried plantains and sweet potatoes. Fried plantain and sweet potato were obtained by frying 2 mm thickness slices in boiling refined palm oil bath at 170°C during 5 min. Steaming and roasting procedures were similar to those of Cameroonians households. The results obtained showed that in raw plantain, vitamin C contents were 41.43 and 45 mg/100 g Dry Matter (DM) in ripe and unripe plantain, respectively. These contents were 70.64 and 77.66 mg/100 g DM in varieties 1112 and TIb1 of sweet potato. β-carotene contents were 1135.60, 829.66, 577.01 and 241.66 μg/100 g DM in unripe and ripe plantains; varieties TIb1 and 1112 of sweet potatoes respectively. Total carbohydrates were 74.91 g/100 g DM in unripe and ripe plantain, 72.72 and 76.39 g/100 g DM in varieties TIb1 and 1112 of sweet potato, respectively. These contents varied significantly (p<0.05) with the cooking methods. Significant losses (p<0.05) of β-carotene and vitamin C were observed in all processing techniques studied. Losses of β-carotene were higher after frying and vitamin C losses were smaller after frying, but higher after roasting. Significant losses of total carbohydrate were also observed after steaming and frying. On the contrary, total lipids content were significantly (p<0.05) higher after frying but did not vary with roasting or steaming. Steaming was then the best cooking method which preserves the above nutrients contents in plantain; variety Big Ebanga and sweet potato; variety TIb1 and 1112.
Gouado Inocent, Demasse Mawamba Adelaide, Etame Loe Gisele, Meyimgo Ouambo Ruphine Solange, Ejoh Aba Richard and Fokou Elie, 2011. Impact of Three Cooking Methods (Steaming, Roasting on Charcoal and Frying) on the β-Carotene and Vitamin C Contents of Plantain and Sweet Potato. American Journal of Food Technology, 6: 994-1001.