In vitroantimicrobial activity and polyphenolics content of tender and matureEbenopsis ebanoseeds

Ebenopsis ebano seeds are traditionally used as a coffee substitute, but their biological potential has not been validated yet. We evaluated antimicrobial activity of tender and mature seed extracts against the clinically relevant strains Escherichia coli, Salmonella enterica var. thyphimurium, and Candida albicans, and determined the phenolics present in the extracts. Treatment groups included raw tender seeds (T1), cooked tender seeds (T2), raw mature seeds (T3), toasted mature seeds (T4), and commercially available mature seeds (T5). We observed significant (p < 0.05) growth inhibition of aqueous extracts vs. E. coli (up to 32%) and vs. S. enterica (up to 25%). Similarly, significant (p < 0.05) growth inhibition of methanol extracts vs. E. coli (up to 30%), vs. S. enterica (up to 20%), and vs. C. albicans (up to 84%) were observed. In addition, we observed differential levels of gallic acid, cafeic acid, and quercetin in aqueous and methanol E. ebano seed extracts, which varied within the treatments (T1–T5). Commercially available seeds (T5) were observed to possess the highest amount of polyphenolics. Differences in polyphenolic levels observed in the treatment groups were not related to the antimicrobial activity or maturity state of the seeds.