CHARACTERIZATION OF ORANGE JUICE (CITRUS-SINENSIS) BY FLAVANONE GLYCOSIDES

A fast and simple method has been developed to detect orange juice (Citrus sinensis) falsifications on the basis of the flavanone glycoside pattern. After a short sample preparation procedure, gradient HPLC is used, followed by photodiode array detection. Separation is done by means of a 15 cm Waters Novapak RP 18 column and a mobile phase gradient, partly replacing an aqueous phosphate buffer solution by acetronitrile. Peak identification is based on relative retention times as well as on UV-vis spectra. On the basis of a minimum hesperidin/narirutin ratio of 3, some doubtful technological processes, as further extraction of oranges, may be traced out, as well as the addition of Citrus reticulata and some orange hybrids. Also, the addition to Citrus sinensis of small amounts of Citrus paradisi, Citrus aurantium, and/or Citrus bergamia may be detected by the presence of naringin or some other flavonoids not present in Citrus sinensis.