Proximate, Mineral and Phytochemical Composition of Dioscorea dumetorum (Bitter Yam) Commonly Cultivated in South Eastern Nigeria

Abstract

Standard procedures were used to investigate proximate, mineral, amylose content, gelatinization temperature and phytochemical composition of Dioscorea dumetorum (Both cooked and fresh samples). Significant increase (p< 0.05) of protein, fats and oil, moisture and crude fibre contents was observed in the fresh sample as against cooked sample. A value of (43.80%) was recorded in the cooked sample while in the fresh sample the carbohydrate value was 23.15%. There is a significant increase (p< 0.05) of Fe, Mg, Na and P concentration of the fresh sample compared with the cooked sample. Inversely, significant decrease (p> 0.05) of, Mn, Ca. and K contents in the cooked sample was recorded in comparison with the fresh plant sample. Gelatinization temperature increased significantly (p< 0.05) in the cooked sample as against fresh. Non- significant increase (p> 0.05) of the amylose content was documented in the fresh sample compared with cooked sample. Phytochemical screening revealed alkaloid, saponin glycosides were steadily present, flavonoid, tannin and phenol were moderately present in the cooked sample. In the same vein, similar observation was made in the fresh sample. Steroids were not detected in both samples. Medicinal use of the tuber is hereby justified by the results and suggests it could contribute to the nutrition of man and animals. It could be recommended to diabetic patients and obedience owning to its low starch contents.