Phenolic profile in the evaluation of commercial quince jellies authenticity

The phenolic profiles of 12 samples of Portuguese commercial and one home-made quince jelly were determined by reversed-phase HPLC/DAD, in order to evaluate their authenticity. Two different extraction methods were needed for the complete definition of quince jelly profile, one of them including an Amberlite XAD-2 cleaning step. These analyses showed that all samples presented a similar profile composed of at least eight identified phenolic compounds. None of the samples were fraudulently adulterated by the addition of pear or apple, since they did not contain arbutin, the characteristic compound of pear, nor phloretin 2′-xylosylglucoside and phloretin 2′-glucoside, considered the chemical markers of apple. All samples exhibited 5-HMF, a sugar derivative, as the major compound.