Abstract: The emulsifying properties of the flour and protein isolates from Mucuna Bean (Mucuna sp.) have been investigated. The pH dependent protein solubility profiles indicated that the isoelectric point of the proteins was between 4 and 5 depending on the species. Generally the solubility reduces as the pH increased until it reaches the isoelectric poiunt. This was followed by a progressive increase in the solubility with further increase in pH. The emulsifying capacity of the flours increases as the concentration of the flour samples increased up to 3% concentration of sample. Subsequent increase in the concentration of the samples reduced the emulsifying activity. The emulsion stability of the flour follow a similar trend except that the increase in the stability was up to 6% sample concentration, after which further increase in the level of the flour reduced the emulsifying stability. Similar trend was observed in the protein isolates, except that a much higher values were obtained. The trends of the emulsifying capacity and stability were similar in M. rajada and M. cochinchinensis for both the flours and protein isolates. There was an increase in the emulsifying capacity and stability as the pH was increased from 2-4. However at pH 5, there was a rapid reduction in the emulsifying capacity and stability while in all other samples (whether flour or protein isolate), there was a corresponding rapid reduction at pH value of 4. The result parallels the trend recorded for the protein solubility because the region of minimum solubility of proteins (isoelectric region) was the region of minimum emulsifying capacity and solubility of the samples. It was found that the emulsifying capacity and stability of the flours and protein isolates increased as the ionic strength was increased from 0.0-0.4M of KCl solution. Thereafter the values of the parameters decreased as the ionic strength was increased to 1.0M. Minimal values of the emulsifying capacity and stability were obtained at ionic strength of 1.0M. The Emulsion Activity Index (EAI) as well as the Emulsion Stability Index (ESI) for protein isolate were determined to allow for comparison of emulsifying properties which were determined using the same technique for similar seeds. The highest EAI value (123 m² g ¹) and ESI value (72 h) was obtained for M. pruriens while corresponding values for M. veracruz white was 98 m²/g and 48 h, respectively. Data for Mucuna isolate as reported in this study are higher than those reported for Soy protein isolate with values of 118 m² g ¹ and 52h for EAI and ESI, respectively. As the temperature was increased from 25-60�C, the viscosity of the flours and the isolates increased. On cooling again to 25�C the viscosity increased further at all pH values. However, minimum viscosity was observed at either pH 4 or 5 (region of isoelectric point) for both the flours and protein isolates. The result of gel electrophoresis SDS-PAGE indicated the presence of a major band consisting of a broad zone with molecular weight 36�7 and 17�3 kDa appeared in all the samples under both reducing and non-reducing conditions. In addition, some minor polypeptide chains (55, 84, 97 and 116 kDa.) gave similar patterns under both reducing and non-reducing conditions. In contrast, a 66 kDa minor fraction disappeared after reduction which resulted in the formation of a smaller polypeptide chain with 24 kDa.