Nutritional Evaluation of Endemic Wild Yam (Dioscorea Comorensis) Tuber Flour Harvested in the Comoros

Abstract

Wild edible yam species remain underutilized despite their recognized potential to enhance food security, dietary diversification, and biodiversity conservation. Among them, Dioscorea comorensis, an endemic and endangered species from the Comoros, has received little scientific attention, and its nutritional potential remains largely unexplored. This study provides the first comprehensive nutritional and phytochemical characterization of flour produced from its tubers. Tubers collected from Ouellah (Ngazidja Island) were processed into flour and analyzed using standardized AOAC methods. Proximate composition, mineral profile, phytochemical constituents, and nutritional indices (PRAL, Ca/P, and Na/K ratios) were determined using atomic absorption spectrophotometry, colorimetry, and qualitative phytochemical tests.The flour exhibited low moisture content (7.13%) and high dry matter (92.87%), with 6.37% protein, 83.37% carbohydrates, and a metabolizable energy value of 357.46 kcal/100 g. It was particularly rich in potassium (780.41 mg/100 g), sodium (599.41 mg/100 g), phosphorus (444.17 mg/100 g), and calcium (422.70 mg/100 g), while also containing appreciable amounts of magnesium, iron, zinc, manganese, and copper. Phytochemical screening confirmed the presence of several bioactive compounds. The negative PRAL value (−9.80 mEq/100 g) indicated an alkalizing effect, whereas the Ca/P (0.95) and Na/K (0.77) ratios suggested a favorable mineral balance. These findings demonstrate that D. comorensis flour is a promising nutrient-rich and functional food resource suitable for composite flour and breadmaking. This study establishes a scientific basis for the sustainable utilization, conservation, and valorization of this endemic species, supporting future strategies to strengthen food and nutritional security in the Comoros.