36E-49 |
|
J. HE1, B. A. Magnuson2, and M. M. Giusti1. (1) Dept. of Food Science & Technology, Ohio State Univ., 2015 Fyffe Ct., 110 Parker Food Science Bldg., Columbus, OH 43210-1007, (2) Dept. of Nutrition & Food Science, Univ. of Maryland, 3309 Marie Mount Hall, College Park, MD 20742-7521 Anthocyanins are natural pigments abundant in fruits, vegetables, and juices. Studies have suggested structural influence on color, stability and antioxidant capacity of individual anthocyanins. Anthocyanin structure may also influence their bioavailability and health promoting effects. Our animal study was designed to evaluate the absorption and excretion of anthocyanins with varied structures, in order to screen potentially "healthier" anthocyanins. Thirty-two F344 rats received diets enriched with anthocyanin-rich extracts (chokeberry, bilberry and grape) or anthocyanin-free diet for 14 wk. Urine and fecal samples were collected before rats were euthanized, at which time plasma, cecal contents and various organs were removed and frozen. Anthocyanins were extracted (when necessary), semi-purified with a C18 cartridge, and analyzed by HPLC coupled to a PDA detector. Anthocyanins and their metabolites in the urine were also analyzed by HPLC-Tandem-MS, using precursor ion scan. Trace amount of intact anthocyanins were detected in urine (24, 8, 15 μg cyanidin-3-galactoside-equivalent/mL for chokeberry, bilberry and grape respectively) and plasma, suggesting low absorption. In urine, considerable amount of methylated cyanidin-glycoside derivatives were found. Anthocyanin concentrations in feces were high and dependant on chemical structures (0.7, 1.8, 2.0 g/kg; chokeberry, bilberry, grape). Anthocyanin profiles from feces and cecal content were similar. In gut content, anthocyanin loss was high for glucosides, moderate for galactosides and negligible for arabinosides and xylosides. Both glycosylation and acylation affected the absorption and excretion. This is the first time that anthocyanin excretion through feces was systematically evaluated. We observed clear effects of sugar substitutions and acylations on the losses of individual anthocyanins in gastrointestinal tract, which provides valuable information to selecting anthocyanin sources for functional foods. Correlating urinary and fecal anthocyanins concentration to a parallel chemopreventive study, we hypothesize that high anthocyanin level in gut content may contribute to colon health, probably due to direct absorption by colon epithelial cells.
Session 36E, Fruit & Vegetable Products: General
2005 IFT Annual Meeting, July 15-20 - New Orleans, Louisiana |