ABSTRACT

African yam bean flour (AYBF) was produced from African yam bean seeds (AYBS) through different processing methods which are: Control African yam bean flour (CAYBF), Boiled African yam bean flour (BAYBF), Soaked African yam bean flour (SAYBF) and Fermented African yam bean flour (FAYBF) which were analyzed for the proximate, minerals, vitamins, anti-nutrients and functional properties. Effects of the different processing methods were investigated. The results obtained indicated that proximate composition of the processed flour ranged from 8.75 to 10.45 % moisture, 17.20 to 25.50 % crude protein, 1.76 to 2.51 % crude fib re, 1.20 to 1.55 % fat, 2.84 to 3.47 % ash, 57.46 to 66.58 % carbohydrate and 345.71 to 349.93 % of energy value; for minerals indications varies from 29.43 to 55.65 mg/lOOg calcium, 285.92 to 312.82 mg/lOOg sodium, 40.01 to 56.17 mg/lOOg magnesium, 117.95 to 140 mg/lOOg phosphorous, 104.88 to 129.65 mg/lOOg potassium, 4.87 to 9.11 mg/lOOg iron and 4.06 to 6.55 mg/lOOg zinc. The vitamins analyzed significantly (p< 0.05) increased for FAYBF samples with values for vitamin A 62.03 to 80.17 pg/lOOg, Bi 0.11 to 0.14 mg/lOOg, C 4.24 to 5.91 mg/lOOg, Bz 0.03 to 0.06 mg/lOOg and B3 1.27 to 1.53 mg/lOOg. The boiled processing decreased in vitamin content. The residual anti-nutrients in the processed flour ranged from 5.07 to 9.25 mg/lOOg phytate, 3.12 to 3.81 mg/lOOg alkaloid, 4.07 to 5.37 mg/lOOg tannins, 7.05 to 18.97 trypsin inhibitor, 2.07 to 2.66 mg/lOOg cyanogenic glycoside and 4.13 to 6.46 mg/lOOg oxalate. The functional properties ofthe processed flour showed some significant differences (p< 0.05) in all functional properties except foam stability which were no significantly (p> 0.05) different in all.the processed flours which varied from 22.04 to 28.66 %. These results proved that all the processing methods which are‘boiling, soaking and fermenting are very effective processes which could lead to increase in the nutritional qualities of African yam bean flour especially in minerals and vitamins due to the reduction in anti-nutritional factors seen in leguminous foods