Valeurs nutritionnelles et potentiel santé de quelques tubercules sous-valorisés du Cameroun: Dioscorea schimperiana Hochst., D. bulbifera L., D. burkilliana J. et Coleus esculentus (N.E.Br.)

Abstract

In the national food security and tuber development strategy, priority is given to certain tubers knoun as predominant tubers, leaving out another group called scarce tubers. The present study focuses on four endangered tuber varieties in Cameroon: Dioscorea schimperiana, D. bulbifera, D. burkilliana and Coleus esculentus. The objective is to collect information on the knowledge of their national distribution and use, carrying out a bromatological analysis, measuring the antioxidant and glucogenic capacities in relationship to their use in the management of chronic diseases. The methodology is based on a food survey of a snowball sample of producers and consumers of these tubers, followed by standard methods of analysis of the nutritional value, anti-nutritional factors and some health potential of foods. It appears that D. bulbifera is found in 9 regions of Cameroon while C. esculentus is mainly found in West and NorthWest regions. They are most often consumed by people with diabetes. Starch (76 to 90 g / 100g DM) is the major determinant of the energy value (363 to 385 Kcal / 100 g DM). The presence of fibres (2 to 8 g / 100 g DM) is favourable for dietary use. The most abundant minerals are potassium (217.25 to 514.37 mg), phosphorus (83.23 to 215.32 mg), magnesium (29.47 to 264.34 mg) and calcium (14.27 to 63.22 mg / 100g DM). Antinutrients are in amounts below the toxicity thresholds. Total phenolic compounds (51 to 3664 mg GAE/100 g DM) among which flavonoids (77 to 11328 mg CE/100 g DM) explain their antioxidant properties. Glycemic index values ranged from 43 (C. esculentus) to 77 (D. bulbifera) making C. esculentus the best scarce tuber for the prevention of diabetes. These tubers deserve to be integrated into root and tuber development programs to contribute to the fight against food insecurity, the prevention of chronic diseases as well as the preservation of biodiversity.