Journal of Global Agriculture and Ecology

Pentaclethra macrophylla seeds (Ugba) are fermented to produce a traditional nutritional staple food condiment known as ugba in southeastern Nigeria. While fermentation is known to improve the digestibility and reduce anti-nutritional factors, its specific impact on the antioxidant potential of ugba remains less explored. This study is aimed to evaluate the effect of traditional solid-state fermentation on the in vitro antioxidant activity of P. macrophylla seeds. Raw seeds were processed and fermented over four days using traditional methods. The antioxidant capacity of aqueous extracts from both raw and fermented seeds was assessed using two standard assays: the 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging assay and the ferric reducing power assay, with Butylated Hydroxyanisole (BHA) as a standard reference. The results demonstrated that fermentation significantly enhanced the antioxidant properties of the seeds. The fermented seed extract exhibited a markedly higher percentage of DPPH radical scavenging activity and a greater reducing power compared to the raw seed extract across all tested concentrations. Crucially, the EC₅₀ value (the concentration required to scavenge 50% of DPPH radicals) for the fermented extract was significantly lower than that of the raw extract, indicating a higher antioxidant potency. This enhancement is attributed to the microbial biotransformation during fermentation, which likely liberates bioactive phenolic compounds and reduces the levels of antioxidant-masking anti-nutritional factors like tannins. The study concludes that traditional fermentation is an effective bioprocessing technique that significantly augments the antioxidant activity of P. macrophylla seeds, thereby elevating ugba from a mere dietary staple to a potential functional food with enhanced health-promoting properties.