Chemical Studies of the Peel of Xanthosoma sagittifolium (Tannia Cocoyam)

Abstract

The peels of xanthosoma sagittifolium (Cocoyam) which is locally called ‘kunkoro’ in ‘Nupe’ land from four farms; randomly sampled to represent the four geographical areas in Bida, Niger State of Nigeria, were analyzed for their nutritive and anti-nutritional contents using standard analytical methods. The nutritive content of the peel and its effect on the period of sampling was also investigated, as a first step in their possible modification for use as animal feed. The results obtained show that samples collected during dry season contained more nutrients (proteins, lipid, etc.) than those collected during the wet season. Macro-minerals (Na, K, Ca and P) being the highest while the micro-mineral nutrients such as Mg, Zn, Fe and Cu etc were found to be generally lower than the dietary mineral requirement for animal feeds. The protein content of the peel ranged between 6.30-17.6%, while fibre and carbohydrate contents were 10.7-19.7% and 41.2-46.0% respectively. The lipid content was generally low and ranged between 0.70-2.14%. The peels collected during dry season contained lower concentration of phytate which ranged between (1.26-1.43%), hydrogen cyanide (3.17-3.20%), soluble oxalate (1.18-1.69%) and tannin (1.43-8.24%) than the peels collected during wet season, with the exception of sample CYD. These anti-nutritional factors in all the cocoyam peel studied were generally low, yet critical to the safety of the consumer as it affects bioavailability of some essential minerals. The proximate analysis of the peels suggests that they could serve as supplementary sources of essential nutrients for livestock production, especially with their low levels of anti-nutritional factors.