Identification and Quantification of Phenolic Compounds and Bioactive Properties of Sorghum-cowpea-based Food Subjected to an In vitro Digestion Model
Oluyemisi E. Adelakun *
Department of Food Science, University of Pretoria, Pretoria 0002, South Africa and Department of Food Science and Engineering, Ladoke Akintola University of Technology, Ogbomoso, Oyo State, Nigeria and Department of Biological Sciences, Covenant University, Ota, Ogun State, Nigeria.
Gyebi Duodu
Department of Food Science, University of Pretoria, Pretoria 0002, South Africa.
*Author to whom correspondence should be addressed.
Abstract
This work identified and quantified some phenolics compound in sorghum-cowpea porridge after subjection to in vitro digestion. Flours, porridge and digested porridge were analysed for total phenolics, total flavonoids, ABTS-radical scavenging capacity and specific phenolic acids and flavonoids. Total phenolics and flavonoid content of the gastric (346.1 µg CE/g; 35.2 µg CE/g) and intestinal phase digest (1389.8 µg CE/g; 142.6 µg CE/g) were lower than the composite flour (2720.1 µg CE/g; 220.9 µg CE/g) and while its porridge were (1218.4 µg CE/g; 173.8 µg CE/g). The ABTS-radical scavenging capacity of all samples ranged from 21.0 – 507.3 µg TE/g. The gastric phase and intestinal phase digests maintained 4.7% and 58.3% of the radical scavenging capacity of the porridge. Catechin and gallic acid were lower in the intestinal digest (2760.0 µg/g; 226.7 µg/g) than the undigested porridge (4188.3 µg/g; 193.9 µg/g). Sorghum-cowpea composite porridge contains phenolic antioxidants even after gastric and intestinal digestion with potential to significantly impact human health.
Keywords: Sorghum, cowpea, in vitro digestion, antioxidant, phenolics acids, flavonoids