Rapid high performance screening method using UHPLC-MS to quantify 12 polyphenol compounds in fresh apples

Abstract

A rapid screening method for quantifying different polyphenol compounds in fresh apples using UHPLC-MS was developed. Apples were frozen and ground to a fine powder, which was extracted with methanol containing 1% formic acid. The resulting supernatant was used directly for total polyphenol determination with the Folin–Ciocalteu reagent and after dilution and filtration for UHPLC-MS analysis. Quantification of individual polyphenols was achieved with an external standard calibration. Four different apple cultivars were analysed with both methods. Braeburn contained the lowest amount of polyphenols (calculated as sum of polyphenols by UHPLC-MS) followed by Gala Galaxy and Golden Reinders with average amounts while Fuji contained the highest concentrations ranging from 24.2 to 50.0 mg per 100 g of edible fresh matter. Total polyphenol content by the Folin-Ciocalteu method showed the same trend, but was 3–4 times higher. Using the rapid high performance screening method the 12 most important polyphenols of apples (catechin, epicatechin, procyanidin B1 and B2, chlorogenic acid, coumaroylquinic acid, phloridzin, phloretin-xyloglucoside, quercetin-galactoside/-glucoside, rutin, quercetin rhamnoside) were quantified.