Evaluation of chemical composition and anti-nutritional factors in raw and toasted African yam bean (Sphenostylis sternocarpa) seeds as feedstufff for monogastrics

Abstract

Chemical composition and anti-nutritional factors of raw and toast African yam bean seeds (AYBS) were evaluated. A known weight of clean seeds was toasted using frying pan of length 74.50cm and breath of 38.00cm for 3-5 minutes. The oven dried samples were analysed for crude protein, crude fibre, ether extract, ash, energy, calcium and phosphorus, phytate, tannin, oxalate, trypsin inhibitor using standard procedures. The results showed that raw African yam bean had 25.90% crude protein, 4.00% crude fibre, 4.00% ash, 3460.93Kcal/kg metabolisable energy, 0.29% calcium and 0.38% phosphorus while toasted seeds had 26.60% crude protein, 4.00% crude fibre, 5.00% ash, 3324Kcal/kg metabolisable energy, 0.31% calcium and 0.42% phosphorus. Raw AYBS contained 0.57% phytate, 0.25% oxalate, 0.09% tannin, 31.26% trypsin inhibitor while toasted had 0.24% phytate, 0.17% oxalate, 0.08% tannin, 28.64% trypsin inhibitor. Toasted AYBS indicated that heat inactivated anti-nutritional factors. Therefore, toasted African yam bean seeds can be used as feedstuff for monogastrics.