Reduction of persimmon astringency by complex formation between pectin and tannins

The effects of interactions between soluble pectin and soluble tannins on the astringency of persimmon fruit were studied. The astringency of both fresh juice and a solution of tannins purified from persimmon fruit was significantly reduced by the addition of soluble pectin. The change was probably due to complex formation between the pectin and soluble tannins. In intact fruit, a reduction in the total pectin content without a rise in water-soluble pectin, during flesh softening, suggests the possible formation of pectin-tannin complexes, which might reduce astringency when the fruit is eaten, with almost no acetaldehyde accumulation. The results suggest that complex formation between pectin and soluble tannins may be a factor, other than acetaldehyde, in reducing astringency in persimmon. (C) 1997 Elsevier Science B.V.