Unique Profiles of Potential Health-Benefiting Phenolic Compounds in 22 Different Citrus Clones and Hybrids

High Resolution Image Download MS PowerPoint Slide Within the genus Citrus, a wide range of flavonoids and coumarins occur that have beneficial effects on mammalian health. Unique profiles of these bioactive compounds were found in citrus clones and experimental citrus hybrids that were created as part of the U.S. Department of Agriculture (USDA) citrus breeding program. The fruit of 22 clones and experimental hybrids, many with significant field tolerance to Huanglongbing disease (HLB), were analyzed for their flavonoid and coumarin contents. Among these selections, unique profiles of these compounds frequently reflected the phenolic compositions of their genetic parents. Consistently high levels of the polymethoxylated flavones nobiletin and tangeretin occurred among common mandarin ( Citrus reticulata ) cultivars. Hybrids between these mandarins and pummelos ( Citrus maxima ) contained similar polymethoxylated flavone profiles as well as widely different coumarin and linear furanocoumarin profiles. Most of the hybrids contained bergamottin-related compounds involved in the reported grapefruit/drug interactions. The analyses of coumarins and flavonoid profiles were extended to two common varieties of trifoliate orange ( Poncirus trifoliata ), “Flying Dragon” and “Gotha Road”. Unexpectedly large differences in the phenolic compound profiles were detected between these two trifoliate orange varieties. Crosses between trifoliate oranges and mandarins yielded fruit with novel compositions of polymethoxylated flavones and coumarins not normally occurring together in traditional citrus varieties. Hybrids among the various species appear to be a rich source of unique combinations of compounds useful for particular health applications.