Proximate analysis, antioxidant activity and glycemic index of Dioscorea alata var cardofolia a yam consumed in Kwango province, Democratic Republic of the Congo

Objective: This study aims to evaluate the biological activities and nutritional value of Dioscorea alata var cordofolia. Tubers of D. alata L., locally known as “kusu” in the Kwango Province in the Democratic Republic of Congo, were harvested in 2018. Methods: For botanical verification, voucher specimens were prepared and deposited in the herbarium of the Faculty of Science, University of Kinshasa, under standard taxonomic protocols. Proximate analysis was performed on this species, and the biological activities referred to the determination of its diuretic, glycemic index, and antioxidant activities. The One-Way ANOVA allowed to compare the means. The IC₅₀ values for both ABTS•⁺ and DPPH• assays were calculated by nonlinear regression analysis using GraphPad Prism version 6.0. The significance level is p ≤ 0.05. Results: The findings showed that proximate analysis of yam extracts indicated 53.4% of moisture, 1.05% of ash, 6.4% of crude proteins, 9.3% of lipids, 1.57% of fibers, 59.8% carbohydrates and 481.02 kcal as the energy value. Regarding the antioxidant and diuretic activities, it was observed to be moderate diuretic and antioxidant capacity though they are not always related. The glycemia in the fasting stage was in compliance with the standard value (< 115 mg/dL). The glycemic index of D. alata was between 50 and 70. Conclusion: The yam exhibited moderate antioxidant activity, a favorable glycemic index, and noteworthy diuretic effects, making it a promising candidate for further investigation as a potential functional food. Thus, D. alata var cordofolia has a high food value and can be developed as a functional food.