Quantitation of polyphenols in different apple varieties.
Forty-one apple samples, representing eight of the most widely cultivated varieties in western Europe, were collected in Trentino, Italy. Samples were extracted from fresh fruit with a mixture of acetone/water to achieve a good extraction of polyphenols, including proanthocyanidin oligomers which were analyzed by normal-phase HPLC. Up to 20 compounds including catechin, epicatechin, B2 procyanidin, hydroxycinnamates, flavonols, anthocyanins, and dihydrochalcones were analyzed by reversed-phase HPLC and LC-MS. Total polyphenol content was independently measured with an optimized Folin-Ciocalteu assay. The mean content of total polyphenols lay between 66.2 and 211.9 mg/100 g of FW depending on the variety. With chromatographic analysis, it was possible to explain the whole amount of total polyphenols measured by the FC assay. Flavanols (catechin and proanthocyanidins) are the major class of apple polyphenols (71-90%), followed by hydroxycinnamates (4-18%), flavonols (1-11%), dihydrochalcones (2-6%), and in red apples anthocyanins (1-3%).
Istituto Agrario di San Michele, via E. Mach 2, 38010 San Michele all'Adige, Italy.
Urska
U
Vrhovsek
Adelio
A
Rigo
Diego
D
Tonon
Fulvio
F
Mattivi
D002851:Chromatography, High Pressure Liquid; D005419:Flavonoids / Q000032:analysis*; D005638:Fruit / Q000737:chemistry*; D027845:Malus / Q000737:chemistry*; D010636:Phenols / Q000032:analysis*; D059808:Polyphenols; D013045:Species Specificity
D005419:Flavonoids; D010636:Phenols; D059808:Polyphenols