Microwave-assisted extraction technology for extracting polyphenols from lotus seedpod

In this study, the microwave-assisted technology for extracting polyphenols from lotus seedpod was investigated, and the results were compared with that of acetone refluxing extraction method. The effects of different factors, including extraction solvent concentration, ratio of material to liquid, microwave power and microwave-assisted extracting time, on the polyphenols extraction rate were studied. On the basis of single factor experiment, the optimum conditions of microwave-assisted extraction polyphenols and procyanidins were obtained by orthogonal experiment. The results were under following conditions: acetone-water solution as extraction solvent (volume fraction of 60%), the extraction time of 90 s, the ratio of material to liquid as 1:25 (g·mL^-1), and the microwave power of 700 W. Under this condition, the yield of poly-phenols and procyandins were 11.88% and 5.58%, respectively, which were 2.1 and 2.6 times compared with the traditional 60% acetone refluxing extraction method. The results of infrared spectrum and HPLC analysis showed that there was no effect by microwave on the polyphenols structure and constitutions in lotus seedpod, and the method was appropriate for extracting polyphenols from lotus seedpod.