Longan seed polyphenol extraction and purification method and application of longan seed polyphenol in preparing polyphenol whitening cosmetics

The invention discloses a longan seed polyphenol extraction and purification method and application of the longan seed polyphenol in preparing polyphenol whitening cosmetics. The method comprises the following steps: respectively treating longan seed powder with anhydrous acetone and a 50-70% acetone water solution three times, merging the second and third filtrates, and recovering the acetone to obtain the polyphenol; and purifying the extracted polyphenol with a macroporous adsorbent resin, and carrying out vacuum concentration to a dry state to obtain the purified polyphenol. The method has the advantages of high extraction rate and recoverable organic solvent; water in the extracting solution does not need to be evaporated by heating; the room-temperature or low-temperature treatment is beneficial to protecting the product and saving the energy; the purified product has higher solubility; and the method is convenient for compounding the product, provides a brand-new application for longan seeds, develops four cosmetics with wide market prospects (polyphenol whitening nutritive facial cleanser, polyphenol whitening nutritive toner, polyphenol whitening nutritive lotion and polyphenol whitening nutritive cream), and also provides a wide-prospect way for integrated application and development of longan seeds.