Abstract: A quantitative determination of total polyphenols from Pyracantha fortuneana were optimized by Folin-Ciocalteu colorimetry with Response surface methodology. The effect of concentration of Folin-Ciocalteu reagent (mol/L) and its addition amount (mL),concentration of Na₂CO₃ solution (g/L) and its addition amount (mL),incubation time and temperature,pH and concentration of ethanol of the solution system on the total polyphenols measurement was investigated thoroughly.On the basis of single factor experiment,the detection conditions of polyphenols from P.fortuneana were further optimized by Box-Behnken design.The results showed the optimal condition for detection was as follows:5 mL of 0.4 mol/L FolinCiocalteu reagent was added into 1 mL suitable concentration of polyphenols extracts from P.fortuneana, after vortex mixing,1 mL of 170 g/L Na₂CO₃ solution was added and mixed,then placing in 34 ℃ water bath and reacting for 40 min,then rapidly cooling with ice water,finally measuring absorbance at the wavelength of 765 nm under room temperature.The developed method had good repeatability and reproducibility,as well as high stability within 1 h and high recovery rate of 99.95%.It was almost not affected by the pH of solution system and the concentration of ethanol in extracts.This method can be applied to detect total polyphenols from other plant sources.

Key words: Pyracantha fortuneana, total polyphenols, Folin-ciocalteu colorimetry, response surface optimization