title: Variance of common flavonoids by brand of grapefruit juice.
abstract: Nine commercial brands of grapefruit juice were analyzed for their flavonoid content by HPLC to determine if significant brand-to-brand variance in grapefruit juice flavonoid content exists. Flavonoid glycosides narirutin, naringin, hesperidin, neohesperidin, didymin, and poncirin have been identified in all the grapefruit juices examined. The aglycone quercetin was detected in only two brands. All the juices were free from methoxylated flavonoid aglycones. There was a significant difference in the amounts of total flavonoids and individual flavonoids in the nine brands. The concentration of total flavonoids ranged between 19.44 and 84.28 mg/100 ml juice. Naringin was found to be the major flavonoid followed by narirutin and hesperidin. Their concentrations ranged from 14.56 to 63.8; 2.25 to 12.20; and 0.24 to 3.12 mg/100 ml juice, respectively.
authors.affiliation: The National Center for Natural Products Research, Research Institute of Pharmaceutical Sciences, Mississippi, MS 38677, USA.
authors.forename: S A
authors.initials: SA
authors.lastname: Ross
authors.forename: D S
authors.initials: DS
authors.lastname: Ziska
authors.forename: K
authors.initials: K
authors.lastname: Zhao
authors.forename: M A
authors.initials: MA
authors.lastname: ElSohly
mesh_terms: D001628:Beverages / Q000032:analysis*; D002851:Chromatography, High Pressure Liquid; D002957:Citrus; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism; D004347:Drug Interactions; D005419:Flavonoids / Q000032:analysis*; D006801:Humans
chemical_list: D005419:Flavonoids; D003577:Cytochrome P-450 Enzyme System