DETERMINATION OF PHLORIN AS PEEL MARKER IN ORANGE (CITRUS-SINENSIS) FRUITS AND JUICES

Phlorin (3,5-dihydroxyphenyl beta-D-glucopyranoside), an orange peel m arker, has been isolated from orange (Citrus sinensis) fruits using C- 18 reversed-phase column chromatography and the structural formula con firmed by H-1 and C-13 NMR spectroscopy and mass spectrometry. Aqueous extracts of orange peel were followed during more than 2 days at two temperatures, showing increasing content of phlorin in water following time. The phlorin content was determined in various parts of two oran ge varieties, Navel Late from Spain and Valencia from Brazil. The rang e of phlorin was only 10-14 mg . L-1 in juice but was in a higher conc entration in albedo (800-1000 ppm).