Formulations of Yellow Maize-based Ogi flour fortified with Orange-fleshed sweet potato (Ipomoea batatas) and African yam bean (Sphenostylis stenocarpa) flours: Effect on the bioactive constituents, colour and pasting properties

Abstract

Yellow maize (YM) formulations fortified with orange-fleshed sweet potato (OFSP) and African yam bean (AYB) flours for ogi production, namely, YAO1 (100 %YM); YAO2 (70YM:10AYB:20OFSP); YAO3 (70YM:15AYB:15OFSP); and YAO4 (70YM:20AYB:10OFSP), respectively were made in order to determine their bioactive constituents, colour and pasting properties. From the results, YAO2 flour was significantly higher (p < 0.05) in 13-cis-βC (5.7 µg/100 g), 9-cis-βC (0.50 µg/100 g), trans-βC (24.17 µg/100 g), total βC (30.36 µg/100 g), α-carotene (1.54 µg/100 g), total carotenoids (44.34 µg/100 g), total polyphenols (9.45 mg GAE/g), total flavonoids (172.12 mg QCE/g), and ABTS (µmol TE/100 g) than other formulations. On the other hand, YAO4 flour had significantly (p < 0.05) higher FRAP value. With the exception of YM L* (lightness) (92.57), colour parameters a* (redness) (2.36), b* (yellowness) (34.72) and ∆E (colour differences) (31.98) were significantly (p < 0.05) higher in YAO2 flour than other formulations. The pasting viscosities of YM exhibited significantly (p < 0.05) higher values for peak (288.62 RVU), Trough (168.38 RVU), Breakdown (120.25 RVU), Final (293.04 RVU), Setback (124.67 RVU), and pasting time (4.77 min) than other formulations. This study revealed that YAO2 and YAO3 flours provided the richest sources of bioactive constituents, lowest pasting properties and acceptable flours which will endear them to good quality ogi production and enhanced biological benefits to consumers.