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Flavanone glycosides (FG) found in citrus juices have been separated and quantitatively determined by reversed-phase liquid chromatography (LC) using a Cle packed column and water-acetonitriletetrahydrofuran-glacial acetic acid eluent system. The influence of juice pH on hesperidin and narirutin determinations, from commercial orange juices, has been studied at different pH values (from 2.0 to 6.2). The response factors, averages, relative standard deviations, and recoveries of six FG were determined using LC with an UV detector at 280 nm. The six FG and three unknown compounds found in citrus juices were determined in 124 samples of lemons, limes, grapefruits, and sweet oranges. The major FG in each citrus group were as follows: in lemon and lime, eriocitrin (47-94 mg L-I) and hesperidin (84-196 mg L-l); in sweet orange, narirutin (30-84 mg L-l) and hesperidin (235-407 mg L-1); in grapefruit, narirutin (33-161 mg L-l) and naringin (113-481 mg L-l). Factorial discriminant analysis of the data obtained effectively differentiated lemon and lime and varieties of grapefruits (white, pink, red, and green) and sweet oranges (Valencia, navel, blood, Thomson, and Malta)

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Pure Valencia orange (Citrus sinensis) juices (64 samples) from Spain, Israel, Belize, Cuba, and Florida, harvested during two seasons (1996-1997 and 1997-1998), were analyzed for their carotenoid profiles. The detection of saponified carotenoid pigments has been achieved and quantitated using a photodiode array detection monitored at 350, 430, and 486 nm. Carotenoid pigments commonly found in the orange variety Valencia have been separated on a polymeric C-30 column using a ternary gradient as eluent. Pure Valencia juices from oranges grown in Mediterranean regions (Israel and Spain) have a high carotenoid content, expressed in beta-carotene (5-18 and 14-35 mg L(-)(1), respectively), compared to those grown in tropical and subtropical regions (Cuba, Belize, and Florida) (4-10, 2-8, and 5-10 mg L(-)(1), respectively). Quantitative results allowed the differentiation of Valencia variety geographical origins, in particular, the Mediterranean area from tropical and subtropical areas, using multidimensional analyses of carotenoid contents.

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