V 630 uv visible spectrometer

The crude propolis (2 g) was extracted with absolute ethanol (40 mL) for 24 hours at room temperature by maceration using a mechanical shaker at 200 rpm followed by centrifugation. The supernatant obtained was filtered and concentrated under reduced pressure to obtain ethanolic extract of propolis (PEE).²⁷ (link) The total polyphenol content in the extract was determined by the Folin–Ciocalteu method.9 , 28 In brief, the PEE (1 mL) was mixed with Folin–Ciocalteu's phenol reagent (1 mL). To this mixture, an aqueous solution of sodium carbonate (7%, 5 mL) was added and diluted to 25 mL with distilled water. Absorbance was measured at 760 nm using the JASCO V-630 UV–visible spectrometer, (Tokyo, Japan) after 90 minutes of incubation of the mixture at room temperature. The total polyphenol contents were expressed in terms of milligram gallic acid equivalents (GAE)/g.

Total polyphenol content of all processed pollen samples was determined by the Folin-Ciocalteu colorimetric method.²¹ Briefly, 1 mL of sample solution was mixed with Folin-Ciocalteu phenol reagent (1 mL). An aqueous solution of sodium carbonate (7%, 10 mL) was added to the mixture followed by dilution to 25 mL with distilled water. After 90 minutes of incubation at room temperature, absorbance was measured at 760 nm using a JASCO V-630 UV-visible spectrometer, (Tokyo, Japan). The blank solutions were made by using corresponding lipid-surfactant mixtures without pollen so as to nullify any possible interference of the lipid-surfactant mix. The total polyphenol content was expressed in terms of mg gallic acid equivalent (GAE)/kg of pollen.