Nature’s powerhouse: antioxidant and antimicrobial potential of South African indigenous medicinal plants for postharvest preservation

While South Africa hosts over 22,000 indigenous plant species, their potential for postharvest preservation is often overlooked, with many species and families remaining underexplored despite their significant biological value.
This study investigated the phytochemical profile (total phenolic and flavonoid content), antioxidant capacity (2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2’-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid (ABTS), and ferric reducing antioxidant power (FRAP) assays), and antimicrobial activity of 70% ethanol extracts of medicinal plants including Artemisia afra, Tulbaghia violacea, and Warburgia salutaris against selected fungi (Botrytis cinerea and Penicillium expansum) and bacteria (Escherichia coli, Enterococcus faecalis and Staphylococcus aureus). Results showed that T. violacea exhibited the highest ABTS radical scavenging activity (73.33%), while all extracts demonstrated strong DPPH activity (82-96.12%). The minimum inhibition concentration for fungi ranged from 1.04 to 3.12 mg mL^‑1, while bacteria ranged from 2.51 to 12.58 mg mL^‑1. All medicinal plants demonstrated strong antioxidant and antimicrobial activity, indicating their potential as sustainable alternatives to synthetic preservatives for postharvest preservation.

IV International Symposium on Beverage Crops

C. Nthimole, T. Kaseke, K.C. Ezeora, O.A. Fawole

antioxidant, antimicrobial, medicinal plants, phytochemicals, postharvest preservation

https://doi.org/10.17660/ActaHortic.2026.1466.21