A comparison of the flavonol content and composition in dessert, cooking and cider-making apples; distribution within the fruit and effect of juicing

The fruit of all apple varieties tested possessed five quercetin glycosides , namely hyperin, isoquercitrin, reynoutrin, avicularin and quercitrin, as the major flavonol components. Total flavonol levels were in the range 26.4 to 73.9 mu g/g fresh wt (expressed as aglycone) with hyperin the dominant form in all varieties except Egremont and Jonagored, where quercitrin predo minated, and the cider apples, where avicularin predominated. The proportio n of flavonol in the peel ranged from 63.0 to 97.1% for the dessert and coo king apples and was not dependent on fruit size. Juice produced from the th ree varieties of cider apple contained 9.9 to 12.7% of the flavonols with t he remainder retained in the pomace. (C) 1999 Elsevier Science Ltd. All rig hts reserved.