Total phenolic content was measured using Folin–Ciocalteu phenol reagent according to a previously described method with slight modifications [45]. Briefly, the samples were vigorously mixed with Folin–Ciocalteu reagent for 5 min, followed by the addition of 20% (w/v) sodium carbonate. After a 60-min incubation at room temperature, the absorbance was recorded at 700 nm using a microplate reader (BioTek). The total phenolic content was calculated using a gallic acid standard curve and expressed as an equivalent of gallic acid (mg GAE/g of dried extract).
The total flavonoid content was measured using an aluminum colorimetric assay, as described previously [46]. The samples were mixed with 50% (v/v) ethanol and 5% (w/v) NaNO2 and allowed to stand for 6 min at room temperature. An Al(NO3)3 solution (10%, w/v) was then added to the mixture and incubated for 6 min. The reactions were stopped by adding 1N NaOH solution. Absorbance was recorded at 510 nm using a microplate reader (BioTek). The total flavonoid content was calculated using a catechin standard curve and expressed as an equivalent of catechin (mg CE/g of dried extract).
Do you have any questions about this protocol?
Post your question to gather feedback from the community. We will also invite the authors of this article to respond.
Tips for asking effective questions
+ Description
Write a detailed description. Include all information that will help others answer your question including experimental processes, conditions, and relevant images.