Functional properties of raw and processed pigeonpea (Cajanus cajan) flour.

Emulsification capacity, foam capacity, foam stability, fat and water absorption of raw and processed pigeonpea flour were investigated and compared with those of raw soy flour. The processing methods included soaking in water, soaking and blanching in water and soaking and blanching with trona, a sodium sesquicarbonate salt. Soaking in water was found to reduce the water absorption capacity of pigeonpea flour while soy flour had a slightly higher water absorption capacity than the other processed flours. All the processing treatments increased the fat absorption capacity of pigeonpea flour and the values were also higher than the value obtained for raw soy flour. Data on the emulsifying activities showed that the trona-treated pigeonpea flour had the highest emulsification capacity and was even higher than that of raw soy flour. Soy flour was found to have higher foaming capacity than all the pigeonpea flour samples.