Abstract:
The effect of compositing red non-tannin sorghum with cream-coloured cowpea and porridge preparation
on phenolic profile and radical scavenging activity was studied. A maize–soybean composite
porridge representing a similar product on the South African market was used as reference sample.
UPLC–QToF-MS-ESI was used to determine phenolic composition of the grain flours, their composites
and porridges. Total phenolic content was determined using Folin–Ciocalteu method while radical scavenging
activity was determined using the ABTS, DPPH and NO radical scavenging assays. Four benzoic
acid derivatives and five cinnamic acid derivatives were identified in the samples. The predominant
flavonoid subclasses identified in sorghum were flavan-3-ols, flavanones and flavones while cowpea
had mainly flavan-3-ols and flavonols with soybean having mainly isoflavones. Compositing the cereals
with legumes significantly (p < 0.01) increased their total flavonoid content and radical scavenging activities.
Sorghum–cowpea composite porridge showed better promise in contributing to alleviating radical
induced oxidative stress than maize–soybean composite porridge.
