Ultrasonic Extraction of Phenolics from Longan Seed by Response Surface Methodology

A Box-Behnken experimental design and response surface methodology (RSM) was employed to optimize the parameters of ultrasonic extraction of phenolics from longan seed based on the single-factor experiments. The effects of extraction temperature, methanol concentration and extraction time on the extraction yield of phenolics from longan seed were investigated. The major parameter influencing the extraction was the extraction temperature. In this experiment, the maximal extraction yield of phenolics was obtained with 5.931 ± 0.016% (n = 3) at extraction temperature 82°C, methanol concentration 50% and extraction time 41 min. Under optimal conditions, the activity predicted by the model agreed well with experimental data.