Phenolic compounds composition and in vitro antioxidant activity of Nigerian Amaranthus viridis seed as affected by autoclaving and germination

Due to the rise in several diseases and conditions, there has been the need for food that possesses supplemental health advantages asides its nutritional advantages. This study evaluates total phenolics, total flavonoids, total antioxidants, and antioxidant activity measured in DPPH radical scavenging activity (DPPH), ferric reducing antioxidant power (FRAP) and metal chelating activity (MCA) of methanol extract of Amaranthus viridis seed with the view of utilizing it as functional food or ingredient. There was also the identification and quantification of phenolic as well as flavonoid compounds with the use of high-pressure liquid chromatography (HPLC). The extracts of amaranth seed exhibited a total phenolic content of 107.89, 95.26 and 164.73 mg tannic acid equivalent/100 g extract for raw, autoclaved and germinated Amaranthus viridis seed respectively. A comparable trend was observed in the total flavonoid as well as the antioxidant content. The strongest radical scavenging activities (48.63 mg tannic acid equivalent (TE)/100 g extract), FRAP (mg Fe (II)/100 g extract) and metal chelating ability (mg ethylenediamine tetraacetic acid/g extract) was observed in germinated flour. An abundance of ferulic and para-hydroxybenzoic acid was observed among the phenolic compounds of the seed of the amaranth. The high efficacy of the seeds of Amaranthus viridis cultivated in Nigeria was demonstrated in this work and it recommends the functionality of the seeds as an important natural antioxidant source.