Abstract: Three batches of apple juice concentrate were treated by the second haze, method and then centrifuged for 20 min (-4 ℃, 18000 r/min) with the superior clear solution collected at last. Determined the solution indexes of polyphenol and protein and compared them with the juices without being treated. The re-haze compounds were ascertained through the change of the indexes. The results showed that: the main phenolic compounds in the re-haze substances are polymers of procyanidin.Catechin and epicatechin are the precursors of formation of haze. The amino acids of protein in haze juice are hydrophobic and the contents of proline are higher in haze juice than in normal juice.

Key words: polyphenol, protein, apple juice, haze