A comparative assessment of nutrients and anti-nutrients contents of varieties of fried yam (Dioscorea specie) commonly consumed in Nigeria

Abstract

There is limited information on nutrients composition of Nigerian foods. As a result, nutrients intake from Nigerian foods is in most cases estimated using foreign food composition tables. This research determined and compared proximate composition, minerals and anti-nutrients in pre- boiled fried New and old White Yam (Dioscorea rotundata), Water Yam (Dioscorea alata) and Yellow Yam (Dioscorea cayenensis) purchased at Yankura market, Kano, Northwestern Nigeria. Samples were peeled, boiled and fried. Fried yam samples were analysed for moisture, protein, carbohydrate, fat, ash, fiber and mineral contents using methods of the Association of Official Analytical Chemist. Phytate and cyanide were estimated bytitration. Results were analyzed using ANOVA in GraphPad Instat software. New White Yam exhibited significantly (P<0.05) higher content in moisture (52.5 ± 8.40 g/100g), fiber (2.0 ± 0.02 g/100g), calcium (13.7 ± 0.5 mg/100g); lower concentration of phytate (11.3 ± 0.08 mg/kg) and moderate concentrations of other parameters studied. Water yam contains significantly (P<0.05) higher protein (5.77 ± 0.2 %), potassium (683 ± 3.6 mg/100g) and moderate amount of other parameters studied. Yellow Yam contains significantly (P<0.05) higher magnesium (16.3 ± 1.52 mg/100g), phytate (31.2 ± 0.40 mg), lower fiber (0.9 ± 0.03 g/100g) and moderate amount of other parameters. Old White Yam contains significantly (P<0.05) higher carbohydrate (37.47 ± 0.5 g/100g), lower cyanide (3.2 ± 0.15 mg/kg) and moderate amount of other parameters studied. The fried yam samples studied have variable amount of nutrients and anti-nutrients. Apart from being excellent energy sources, all yam samples studied could contribute to intake of micronutrients.

Keywords: Fried yam, proximate content, micronutrients, anti-nutrients