Abstract

The effect of temperature and period of blanching on the pasting and functional properties of the flour obtained from plantain (Musa AAB) blanched under three temperature regimes were studied. Plantain fruit fingers were washed, hand-peeled and manually sliced into cylindrical pieces of 2 mm thickness. Blanching was carried out on the sliced samples in hot water at 60, 80 and 100°C for varied periods of 5, 10 and 15 min and dried in the air oven at 65°C (24/h), while the un-blanched sample served as the control. Results showed that blanching temperature and time variation had significant effects (P < 0.05) on pasting and functional properties of the plantain flour. The peak viscosity ranged between (355.25 to 527.08 RVU), trough of (235.83 to 335.92 RVU), breakdown of (91.92 to 217.67 RVU), final viscosity of (302.75 to 434.92 RVU), setback of (64.58 to 103.08 RVU), peak time of (4.52 to 4.91 min) and pasting temperature of (81.55 to 83.23°C) across the blanching temperature and time chosen. The blanched samples were significantly different (P > 0.05) from each other and from the un-blanched control. However, varying the blanching time did not show any significant difference in water and oil absorption capacity for each temperature chosen compared to the control, the bulk density varied between (0.194 to 0.420 g/ml), emulsion capacity (17.86 to 41.12%) while the control was 39.84% which was significantly different from the other samples. Least gelation concentration varied between (2.0 to 6.0%). Samples blanched at 60°C for 5, 10 and 15 min were not significantly different from each other but were significantly higher than that of the control which was (2%). Results indicated that the blanched plantain flours could be utilized as substitutes for soya and wheat flours in complementary/weaning foods and also useful as an important consideration in the production of pastries. Blanched plantain flour will be useful as a better binder and meat extender than the unblanched plantain flour. Blanching at low blanching temperature produced a flour of low stability against retrogradation than those at high temperature. 

Key words: Plantain, flour, blanching, functional and pasting properties.