Mrx 2 plate reader

Total phenolic content was determined using the Folin-Ciocalteu colorimetric method [18] , which was modified by our laboratory [19] . Briefly, all extracts were diluted 1∶20 with distilled water to obtain readings within the standard curve ranges of 0.0–600.0 µg of gallic acid/mL. The grape extracts were oxidized by the Folin-Ciocalteu reagent and the reaction was acted in sodium carbonate. The absorbance was measured at 760 nm, after 90 min at room temperature by a MRX II Dynex plate reader (Dynex Technologies Inc., Chanilly, VA). The absorbance values were then compared with those of standards with known gallic acid concentrations. All values were expressed as the mean (milligrams of gallic acid equivalents per 100 g of fresh sample) ± SD of three replications.

Folin-Ciocalteu colorimetric method [39 ] was used in the determination of tea leaf extract’s phenolic content. The sample extracts were diluted 1:20 with distilled water to obtain readings within the standard curve ranges of 0.0–600.0, lg of gallic acid per ml. The tea leaf extracts were oxidized with the Folin- Ciocalteu reagent, and the reaction was neutralized with sodium carbonate for 90 min at room temperature; the relative absorbance was measured at 760 nm by an MRX II Dynex plate reader (Dynex Technologies Inc.VA, USA). The absorbance values were then compared with those of standards with known gallic acid concentrations. All values were stated as the mean (mg gallic acid equivalents per g tea leaf extract) ± SD for three replications.