A PREVIOUS STUDY OF PHENOLIC PROFILES OF QUINCE, PEAR, AND APPLE PUREES BY HPLC DIODE-ARRAY DETECTION FOR THE EVALUATION OF QUINCE PUREE GENUINENESS

An HPLC/DAD methodology for separating 13 phenolic compounds is descri bed. This methodology is applied to the definition of qualitative and quantitative profiles of quince, pear, and apple purees and a blending of these purees. Two different extraction methods were needed for the complete definition of their profiles, one of them including an Amber lite XAD-2 cleaning step. The analysis of phenolics of each fruit pure e profile and that of a blending seems to indicate that this methodolo gy can be applied to the detection of apple and/or pear fraudulently a dded to quince puree. The presence of apple can be detected by phloret in 2'-xylosylglucoside and phloretin 2'-glucoside, while that of pear is detected by arbutin. In addition, 3-O-caffeoylquinic acid is presen t at a considerable relative amount (similar to 23.4%) in quince puree , while the sample of pear puree contains only 8.2%; this compound is absent in apple puree.