Phlorin screening in various citrus species and varieties

Phlorin (3,5-dihydroxyphenyl beta -D-glucopyranoside), an orange peel marke r, has been searched in 45 species and varieties of Citrus. The phlorin con tent was determined by high-pressure liquid chromatography in juices and aq ueous peel extracts of these different fruits. The phlorin content in C. re ticulata peel extract varies from 0 to 1012 mg L-1 with a mean of 162 mg L- 1. On the contrary, phlorin was not found in mandarin and clementine juices except for mandarin "Commune" and "Beauty'' (33 and 30 mg L-1, respectivel y). In the 14 species of oranges and varieties, phlorin was detected in jui ces and peel extracts with a mean of 22 and 492 mg L-1, respectively, while for grapefruits, means were 108 mg L-1 in juices and 982 mg L-1 for peel e xtracts. Tangors and tangelos which are hybrids (C. reticulata x C. sinensi s and C. reticulata x C. paradisi, respectively) are characterized by the s ystematic presence of phlorin in peels (mean: 406 and 659 mg L-1, respectiv ely) while in juices its presence could be variable (0-73 mg L-1). These he terogeneity and values may be explained by the genetic variability of these hybrids and the phlorin content of their parentage group.