Caftaric and coutaric acids in fruit of Vitis

Abstract

The contents of trans and cis caftaric and coutaric acids were determined by HPLC under conditions fully protecting against oxidation in berry juices from five non- Vitis species, 28 Vitis species, 20 white and 17 red Vitis vinifera cultivars, six Vitis labrusca cultivars and 11 other varieties. These components appear to be genetically determined to a considerable degree. Replicate samples of the same variety from different sources generally gave similar composition. The compounds were absent from or present only in trace amounts in Vitis rotundifolia and four (of five) non- Vitis species. Other Vitis species all contained them but the content ranged from 5 mg/1 to 1350 mg/1 of caftaric and from a trace to 340 mg/1 of coutaric acid. Cultivars of Vitis vinifera did not differ appreciably whether white or red berries were involved, but ranged from 16 to 430 mg/1 of trans-caftaric acid, averaging 145 mg/1. Vitis labrusca and its cultivars averaged notably higher and hybrids were generally intermediate with their parent species. The cis percentage increased, particularly for coutaric with the varieties arranged in order of decreasing caftaric concentration, but appeared to reflect environmental rather than genetic influences. The proportion of coutaric acid, however, appeared quite variable (3-33 % of the caftaric content in the vinifera cultivars) by variety and was apparently genetically controlled.