ABSTRACT

 A comparative study of the vitamin, amino acid and fatty acid compositions of the edible and in-edible species of potato yam (dioscorea bulbifera} was carried out. The results show that the in-edible specie has a higher composition of nonessential amino acid with the value of 50.8g/100g and 45.6g/100g for tire edible, with glutamic acid and aspartic acid averagely high. Glutamic acid had values of 11.94g/100g for the in-edible and 11.01g/100g for edible, while aspartic acid had values of 9.82g/100g for in-edible and 9.25g/100g for edible, cystine was recorded the lowest with the value of 1.11 g/lOOg for in-edible and 0.83g/100g for edible. The in-edible specie is also higher in the essential amino acid composition with the value of 21.71g/100g and 19.6g/100g for the edible specie. The fatty acid analysis carried out showed that only two fatty acids were detected in the edible specie while three fatty acids were detected in the in-edible specie. Oleic acid was observed to be the most predominant fatty acid with the values of (37.47%) for inedible specie and (5.81%) for edible specie, palmitoleic acid (54.00%) for in-edible specie but was not detected in edible specie, linoleic acid (94.18%) for edible specie but was not detected in non-edible specie, linolenic acid (8.52%) for inedible but was not detected in edible specie. The vitamin analysis result showed that vitamin C had the highest value of (92.00mg/100g) for edible and (65.32mg/100g). Followed by vitamin E with the values of (83.33mg/100g) for edible and (72.81 mg/100g) for in-edible. Niacin (33.74mg/100g) for edible and 48.31 for in-edible. The least are vitamin A (2.521u) for edible but was not detected in tire in-edible specie, and thiamin with the values of 5.16 (mg/100g) for edible specie and (0.19mg/100g) for in-edible specie. Riboflavin was not detected in either ofthem.