Comparative study of the nutritional composition of the green stages of fruits of FHIA-21 (tetraploid hybrid), French Horn and False Horn as well as the effect of steam blanching on some selected functional properties of their flours were determined by the Kwame Nkrumah University of Science and Technology in Kumasi, Ghana. The standard AOAC methods were used to determine the nutritional composition. The results showed that the nutritional composition of the hybrid were different from that of French and False Horn. The hybrid had higher fat content (4.05%) than French (1.24%) and False Horn (3.47%). FHIA-21 also compared favorably with that of False and French horn in terms of moisture (69.50%), ash (2.45%), fibre (1.62%), potassium (1150 mg/100 g), sodium (43 mg/100 g) and iron (1.01 mg/100 g). Blanching significantly increased the solubility of FHIA-21 but decreased that of False Horn and French Horn; increased the swelling power of all three plantain varieties and decreased the water binding capacity among all three plantain varieties. Blanching also increased the pH of the flour of FHIA-21 but decreased that of French and False Horn and though insignificant (p>0.5) increased moisture uptake in all three plantain varieties.