Optimization of Extraction Process for Polyphenols from Blueberry Leaves by Response Surface Methodology

This study was designed to optimize the extraction of polyphenols from blueberry leaves using ethanol as the extraction solvent.Four extraction parameters such as ethanol concentration(P = 0.0025),extraction temperature P = 0.0091),solid-to-liquid ratio(P = 0.0236) and extraction time(P = 0.0156) were identified as main variable that influence extraction efficiency through the combined use of one-factor-at-a-time method and Plackett Burman design.The optimum extraction conditions were determined by response surface methodology to be 62.05% ethanol concentration,67.54 ℃,1:23.65 solid-to-liquid ratio and 2.06 h.The maximum predicted yield of polyphenols under these conditions was 90.49%,which was close to the measured value.Thus,the fitted quadratic regression model is valid.