Analysis of phenolic compounds in the evaluation of commercial quince jam authenticity

The phenolic compounds present in 17 samples of Portuguese commercial and t hree homemade quince jams were analyzed by reversed-phase HPLC/DAD, to dete rmine their authenticity. Two different extraction methods were needed for the complete definition of quince jams profiles, one of them including an A mberlite XAD-2 cleaning step. These analyses showed that all the samples pr esented a similar profile composed of at least eight identified phenolic co mpounds, several unidentified characteristic procyanidin polymers, and sodi um benzoate as preservative of quince jams. Several samples also contained arbutin, suggesting that these quince jam samples were fraudulently adulter ated with pear puree.