Abstract: In this study, the optimal extraction conditions of total polyphenols from the flowers of Chinese chestnut cultivar Yanlong were investigated. The traditional heating reflux method was used for the extraction of total polyphenols. Four different extraction solvents were applied for the extraction of polyphenols. The results indicated that methanol was the best extraction solvent, and microwave was superior to ultrasonic in enhancing the extraction of total polyphenols. The optimal process parameters for microwave-assisted extraction of total polyphenols were determined by orthogonal array design to be 40% methanol as the extraction solvent, microwave treatment time of 60 s, microwave power of 480 W and material-to-liquid ratio of 1:25 (g/mL). Under the optimal extraction conditions, the extraction rate of total polyphenols from chestnut flowers was up to 6.69%.

Key words: Chinese chestnut flower, polyphenols, extraction, optimization