Localization and Changes in Catechin and Tannins During Development and Ripening of Cottonseed

Summary Tannnins and their precursor, (+)‐catechin, are localized primarily in the pigmented layers of the cottonseed coat and in seed linters. Lesser quantities are localized in the nucellus and in the palisade parenchyma of embryo cotyledons. Oxidation of seed coat tannins during seed ripening is accompanied by seed coloration and reduction of seed coat permeability to water. Localization and changes in cottonseed flavanols and tannins during seed development and ripening are consistent with their proposed functions as (1) chemical barriers against infection by fungi, (2) physical barriers against absorption of water, and (3) chromogens in baked products containing cottonseed products.