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The bioavailability of raspberry anthocyanins and ellagitannins in rats
Author(s) -
Borges Gina,
Roowi Suri,
Rouanet JeanMax,
Duthie Garry G.,
Lean Michael E. J.,
Crozier Alan
Publication year - 2007
Publication title -
molecular nutrition and food research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.495
H-Index - 131
eISSN - 1613-4133
pISSN - 1613-4125
DOI - 10.1002/mnfr.200700024
Subject(s) - ellagic acid , blowing a raspberry , ileum , anthocyanin , chemistry , food science , ingestion , jejunum , bioavailability , urine , excretion , bilberry , caecum , stomach , duodenum , polyphenol , biochemistry , biology , medicine , pharmacology , antioxidant
Abstract The fate of anthocyanins and ellagitannins in rats was monitored following ingestion of raspberry juice. After 1 h low nM concentrations of unmetabolised anthocyanins were present in plasma but these declined by 2 h and after 4 h they were no longer detectable. For the first 2 h there was an almost full recovery of anthocyanins as they passed from the stomach through the duodenum/jejunum and into the ileum. After 3 h less than 50% were recovered, and the levels declined rapidly thereafter. Excretion of raspberry anthocyanins in urine over a 24 h period was equivalent to 1.2% of the amount ingested. Trace quantities of anthocyanins were detected in the caecum, colon and faeces and they were absent in extracts of liver, kidneys and brain. Urine also contained a number of phenolic acids but most were present in quantities well in excess of the 918 nmol of anthocyanins present in the ingested juice. These findings indicate that raspberry anthocyanins per se are poorly absorbed, probably prior to reaching the ileum, and that substantial amounts pass from the small to the large intestine where they are degraded by colonic bacteria. Ellagitannins disappeared in the stomach without accumulation of ellagic acid.