EFFECTS OF BLANCHING CONDITIONS ON THE QUALITY CHARACTERISTICS OF PLANTAIN FLOUR

Abstract

The effect of blanching conditions on the proximate, mineral composition, functional and pasting properties of flour produced from plantain (Musa AAB) was investigated in this study. Mature green plantain fruits (Musa AAB) obtained from the International Institute of Tropical Agriculture (UTA), Ibadan were washed, peeled and sliced into cylindrical pieces of 2 mm thickness. Blanching was carried out on different samples at 60, 80 and 100°C for 5min, 10min and 15min at each temperature. This was then followed.by oven drying at 6SoC for 24 hours. Cooled samples were milled into flour, sieved, packaged into polyethylene bags for subsequent analysis. The flour obtained was analysed for proximate composition, functional properties, pasting properties, microbiological analysis and sensory evaluation of 'amala' made from the reconstituted plantain flour using a 9-point Hedonic scale. Results showed that blanching and dehydration processes had a, significant effect (p< 0.05) on the proximate composition, pasting properties and functional properties of the flours; as well as on consumer acceptability of amala obtained from the flours. The Control had higher protein content (5059%) but lower carbohydrate content (84.S1 %) compared to all the blanched samples. Also, sample UPBgo- 5, UPBgO-lO and UPBgo- 15 had a fat content of 1.90, 2.41 and 2.16%, respectively which were also significantly lower (p< 0.05) than the Control (2.63%). There was no significant difference on samples blanched at 60°C for 10 and 15 minutes on Phosphorous, Iron and Potassium contents but further increase 'in blanching temperature led to a significant difference (p < 0.05) in all the minerals when compared with the Control except for iron that ranged between 0.12- 0.14%. The pasting properties of the flour including peak viscosity, [mal viscosity, setbabk viscosity and pasting time of blanched samples were significantly different (p< 0.05) from each other and from the unblanched Control. All blanching treatments did not show any significant difference in water and oil absorption capacity compared to the Control except for bulk density, solubility and swelling power. Low blanching temperature (60DC) was preferred for taste and texture, while samples blanched at 80DC however identified as best in colour. Blanching at 100DC had a significant effects (p < 0.05) on bacterial, mould and yeast counts.