Changes in catechin and procyanidin contents during fruit development of two apple cultivars

Catechins, procyanidins and other major phenolics in developing 'Tsugaru' a nd 'Fuji' apples (Malus pumila M.) fruit were identified and quantified by spectrophotometric, thin layer chromatographic and high performance liquid chromatographic assays and their changes observed. 1. Polymeric procyanidin was the most abundant polyphenol in both cultivars . Chlorogenic acid, other hydroxycinnamic esters, (+)- catechin, (-)-epicat echin, oligomeric procyanidins and phloridzin were major phenolics in the e thyl acetate extractable fraction. 2. The total amount of catechins and procyanidins (total catechin units) co ntent decreased on a fresh weight basis, whereas it increased on a fruit ba sis during fruit development in both cultivars. 3. Catechins (monomeric form of procyanidins) and polymeric procyanidin wer e the predominant components in fIavan-3-ol group 30 days after pollination (DAP). Oligomeric procyanidins and (-)-epicatechin content on a fruit basi s increased by the middle stage of development and decreased thereafter, wh ereas polymeric procyanidin increased as fruits matured. 4. (+)-Catechin, procyanidin B1 and especially chlorogenic acid content in 'Fuji' were higher than those in 'Tsugaru'. Chlorogenic acid content increa sed only in 'Fuji'. Although phenolic contents in 'Tsugaru' and 'Fuji' flesh were slightly diff erent, the pattern of seasonal changes in catechins and procyanidins conten ts was similar. Apparently, monomeric and oligomeric procyanidins which tem porarily increased were converted to polymeric form during fruit developmen t.