This research aimed to evaluate the antioxidant and antimicrobial potential of aqueous extracts derived from Hibiscus rosa-sinensis and Delonix regia flowers, with the objective of exploring their applicability in the formulation of functional food products. The antioxidant capacity of the extracts was assessed using the DPPH radical scavenging assay and the ferric reducing antioxidant power (FRAP) method. The phenolic content of the extracts was quantified using the Folin–Ciocalteu method. Antimicrobial properties were examined against Escherichia coli, Pseudomonas, Bacillus cereus, and Staphylococcus aureus through the agar well diffusion technique. The results revealed that both flower extracts possessed notable antioxidant and antimicrobial activities. Results from the DPPH and FRAP assays showed that Hibiscus rosa-sinensis exhibited significantly stronger antioxidant potential compared to Delonix regia. The antioxidant potential was closely associated with the total phenolic content of the extracts. Specifically, Hibiscus rosa-sinensis (47 ± 0.175) showed higher total phenolic content than Delonix regia (48.8 ± 0.123). Furthermore, both extracts suppressed the growth of foodborne pathogens at higher concentrations against the tested strains.
A.A et al. (Sat,) studied this question.