CHARACTERIZATION OF ORANGE JUICE (CITRUS-SINENSIS) BY POLYMETHOXYLATED FLAVONES

As a complement to the flavanone glycoside pattern, the pattern of polymethoxylated flavones (PMFs) may be very efficient in detecting orange juice (Citrus sinensis) falsifications. The method developed is based on gradient HPLC followed by photodiode array detection after extraction of the PMFs in benzene. Separation is done with a 15 cm Waters Novapak RP18 column and a mobile phase gradient, which increases the acetonitrile level in the presence of tetrahydrofuran. C. sinensis authenticity criteria have been proposed for the seven main PMFs present in orange juice based on their average relative peak areas and the corresponding standard deviations ((x) over bar +/- sigma) at 340 mn. The addition of small quantities of tangerine and Murcott juice may be established by significant changes in the PMF pattern.