The Black bean (Phaseolus vulgaris) seeds were processed into full fat flour, defatted flour, protein concentrate and protein isolate. The physico-chemical and functional properties of some of the flour samples were investigated. The effects of pH and temperature on some functional properties of the samples were also examined. The protein content of the concentrate and isolate had a higher value of 47.50% and 78.01% respectively compared with full fat and defatted flour that had 22.70 ± 0.00% and 24.51± 0.01% respectively. The protein concentrate and isolate have no fat and fibre content. The protein, carbohydrate, moisture, fat and fibre content had significant difference on different flour samples at p<0.05. The water absorption capacity had significant difference on the defatted and full fat flour at p<0.05. The effect of temperature on the water absorption of the flours increased with increasing temperature. There is decrease in wettability with increase in temperature as well foaming capacity which increased with increasing temperature. The effect of pH had higher wettability and foaming capacity. pH lowered water absorption and swelling index of the defatted and full fat flour. The black bean flour had good functional properties and thereby can be used in the food system.
Keywords: Black bean, Flour, functionality, physico - chemical, protein concentrate, protein isolate