No abstract

The aim of this study was to investigate the possibility of using overripe banana and plantain mixed with maize to develop composite flours for making doughnuts. The fresh pulp of banana or plantain at maturity stage 7 (appearance of black spots on the surfaces of their peels) was substituted by maize flour at levels of 5, 10, 15, 20, 25, 30 and 35% for composite flours production. The sensory properties of flours were evaluated to prepare doughnuts. Banana or plantain fresh pulps compared with maize flour showed significant (p < 0.05) differences in the crude contents of ash (1.03 ± 0.21% to 5.07 ± 0.15%), fiber (0.75 ± 0.22% to 4.71 ± 1.53%), sugars (9.53 ± 0.31% to 77.92 ± 3.14%), starch (1.37 ± 0.11% to 85.64 ± 1.88%), proteins (2.71 ± 0.11% to 4.23 ± 0.25%) and fat (0.15 ± 0.10% to 1.15 ± 0.21%). Banana-maize mixtures at higher levels (25-35%) of maize flour incorporation produced flours with higher water (WAC) and oil (OAC) absorption capacities and a higher water solubility index (WSI). While plantain-maize mixtures were associated with flours of higher peak viscosity, final viscosity, setback and breakdown indexes during the heating time; meanwhile the pasting temperature was higher in bananamaize flours. It was observed that there was no significant difference (p > 0.05) in the overall acceptability (7.46 ± 1.26 to 8.14 ± 1.21) of banana and plantain doughnuts in 35% incorporation of maize. Furthermore, the results revealed that more than 33% of the panelist greatly like the doughnuts made from composite flours. Technically, organoleptically acceptable doughnuts were formulated from banana-maize and plantain-maize composite flours using 65:35 (w/w) ratio of banana:maize and plantain:maize mixtures.

In this study, the overripe plantain has been used to produce high-antioxidant powders, using Adansonia digitata L. pulp and Hibiscus sabdariffa L. calyces as antioxidant supplements. The constrained mixture design (ranged between 0.9-1.0 for plantain and 0-0.1 for supplements) was used to generate ten powder formulations. The obtained powders were evaluated for physicochemical properties and antioxidant activities. Generally, significant differences (p < 0.05) were found between moisture, proteins, ash, fibers, carbohydrates and fat contents of different raw material powders. The increase in the proportions of A. digitata L. and H. sabdariffa L. significantly increased (p < 0.05) the levels of polyphenols (40.19-583.46 mg GAE/100 g DM), flavonoids (18.27-103.46 mg RE/100 g DM), condensed tannins (28.73-276.47 mg CE/100 g DM), carotenoids (8.41-9.48 mg/100 g DM) and vitamin C (31.55-77.30 mg/100 g DM) in the formulated powders. The antioxidant properties of the powder formulations revealed higher radical-scavenging activities DPPH (IC 50 of 0.80 mg/mL) and ABTS (IC 50 of 1.51 mg/mL) for M10 formulation consists of 91.67% overripe plantain, 1.67% A. digitata L. and 6.66% Hibiscus sabdariffa L. The best reducing powers were found in M5, M6 and M10 formulations which improved by more than 2 to 3 times the value of M1 (2.66 mg AAE/g DM) not containing antioxidant supplements. M10 was the powder formulation that exhibited the best antioxidant activities despite its low hydration capacity. A. digitata L. pulp and H. sabdariffa L. calyces revealed the potential for an efficient improve of antioxidant activity of overripe plantain powder. High-antioxidant powders from the mixtures showed promise in helping to combat oxidative stress in Africa and other countries where chronic diseases pose a threat.