Phenolics, Antioxidants and Minerals in Fermented vs Unfermented Terminalia catappa

Background and Objective: There has been growing interest in preventing oxidative stress, and investigating the potential of medicinal plants to combat it has gained momentum. This study explores the antioxidant properties, phenolic compositions, and mineral content of both fermented and unfermented T. catappa leaf extracts. Materials and Methods: Terminalia catappa leaves were divided into two portions of which one was wrapped with plantain leaves to facilitate fermentation. Both samples were air-dried and milled into powder. Ethanolic extracts (5 g/100 mL) of each sample were prepared to determine the above-mentioned assays. Statistical significance was evaluated using a One-way Analysis of Variance (ANOVA), followed by Dunnett’s post hoc test. Data points correspond to the mean of independent experiments and error bars; the level of significance was set at p<0.05. Results: The unfermented extract exhibited a higher significant difference (p<0.05) in antioxidant properties and phenolic contents. The HPLC analysis also followed the same trend with the presence of higher contents of quercetin, caffeic acid, ferulic acid, maleic acid, p-coumaric acid, and naringenin in unfermented T. catappa. However, the fermented extract was observed to contain additional bioactive compounds such as salicylic acid and apigenin, which are also known for antioxidant potential. In addition, the fermented extract was also observed to have a higher content (p<0.05) of potassium and manganese, while calcium, magnesium, iron, copper, sodium, and zinc were higher in the unfermented extract. The overall results of the analysis showed that the unfermented extract of T. catappa had higher antioxidant activity, phenolic contents, minerals, and HPLC-identified contents. Conclusion: However, the contents of fermented extract unique compounds suggest that fermentation not only alters the phytochemical profile but can also enhance the production of additional components that are needed for health benefits, which could be adopted in managing oxidative stress and related chronic diseases.