Concentration of polyphenolic compounds of fraction number 4 (AF4) determined by LC-MS/MS.

amean ± standard deviation of the mean for three determinations. Phenolic Constituents in AF4. The total of major phenolics present in AF4 determined by LC-MS/MS to be 12132.7 µg/ml. The major polyphenolic compounds detected in AF4 belong to subclasses of flavonols, anthocyanins, dihydrochalcones, flavan-3-ols, phenolic acids and flavanols and were similar to those reported by other investigations of apple skins. The most abundant phenolics in AF4 were quercetin-3-O-galactoside, quercetin-3-O-rutinoside, quercetin-3-O-glucoside, quercetin-3-O-rhamnoside, chlorogenic acid and (−)-epicatechin.