Determination of total polyphenol, flavonoid, and polysaccharide contents in culantro (Eryngium foetidum L.)

Culantro (Eryngium foetidum L.) is a culinary and medicinal plant containing valuable bioactive compounds, including phenolics, flavonoids, and saponins. This study aimed to determine the total phenolic content (TPC), total flavonoid content (TFC), and total saponin content (TSC) in the whole plant of culantro. Raw culantro were collected from the medicinal plant garden of Cuu Long University, dried at 45°C to a moisture content below 10%, ground into fine powder, and used for chemical analyses. TPC was determined using the Folin–Ciocalteu method, TFC was measured by the aluminum chloride colorimetric method, and TSC was quantified using the vanillin–sulfuric acid method. All experiments were performed in triplicate. The results showed that the TPC, TFC, and TSC values were 31.82 ± 1.85 mg gallic acid equivalents/g dry weight (mg GAE/g DW), 12.64 ± 0.91 mg quercetin equivalents/g dry weight (mg QE/g DW), and 42.37 ± 2.76 mg oleanolic acid equivalents/g dry weight (mg OAE/g DW), respectively. Under the analytical conditions of this study, the TSC value expressed as mg OAE/g DW was higher than the TPC and TFC values expressed as mg GAE/g DW and mg QE/g DW, respectively. These findings indicate that culantro (Eryngium foetidum L.) contains considerable levels of bioactive compounds and provides scientific data for further studies on extraction optimization, biological activity evaluation, and value-added product development from this plant material.