Effect of Moringa oleifera leaf powder inclusion on the phytochemical and antioxidant activity of akamu
Moringa leaf powder (MLP) was added akamu at 10%, 20%, 30% and 40% levels of incorporation and labelled MA1, MA2, MA3 and MA4 respectively. Another batch of MLP was blended with an equal amount of soybean powder (SBF) and similarly incorporated into akamu at the same levels and labelled MSA1, MSA2, MSA3 and MSA4. Akamu supplemented with 40% soybean flour (SBA) and unsupplemented akamu (AKM) served as controls. The total phenolic content of akamu increased from 0.35 to 3.06 g/100g, flavonoids increased from 0.06 to 0.27 g/100g for AKM and MA4, respectively. The total phenolic content for SBF incorporated akamu increased (p < 0.05) from 0.35 g/100g to 1.71 g/100g, flavonoids increased (p < 0.05) from 0.06 g/100g to 0.25 g/100g for AKM and MSA4 respectively. The percentage DPPH scavenging activity of akamu was enhanced significantly (p < 0.05) by the addition of MLP and SBF. The DPPH activity of MA4 (88.91%) was significantly higher than that of the AKM (33.40%). Similarly, the DPPH activity of MSA4 (86.34%) was higher than that of AKM. There were significant (p < 0.05) increases in reducing power with levels of addition of both MLP and SBF. The reducing power was elevated from 2.30 mg/g for AKM to 28.8 mg/g for MA4 and to 39.9 mg/g for MSA4. The inclusion of moringa leaf powder (with or without soybean flour) was able to significantly increase the antioxidant activity of akamu, thus enhancing its functional status.
Keywords: Moringa leaf powder, soybean flour, phytochemicals, antioxidant activity