Apple polyphenols are phytochemicals concentrated in the skin of unripe apples.The polyphenol content differs according
 to maturity rate. Young apple has 10 times content comparing with mature apple. Therefore, it is better to use young apple
to get the apple polyphenols. Crude apple polyphenols contain chlorogenic acid, catechins, epicatechin, apple condensed
tannins, phlorizin, phloretin, anthocyanin and etc.