2.8. Determination of total phenolic content (FC GAE)
The concentration of total phenolic content in the honey
solutions was determined by the Folin–Ciocalteu procedure
(Singleton et al., 1999) with some minor modifications. Honey
was dissolved in distilled water to the concentration of 1 g/mL with
the help of ultrasonic bath. The volume of 200 mL was mixed with
1000 mL of FC reagent previously diluted with the distilled water in
proportion 1:10. After 6 min standing in the dark, 800 mL of 7.5%
sodium carbonate solution were added, shaken and left in the dark
for next 2 h to react. After reaction, absorbance on 740 nm was
measured. The total phenolic content of honeys was expressed as
gallic acid equivalents (GAE,mg/mL of gallic acid ormg of gallic acid
per gram of honey because concentration of honey was 1 g/mL).