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Degradation and metabolism of 14 C‐labelled proanthocyanidins from carob ( Ceratonia siliqua ) pods in the gastrointestinal tract of the rat
Author(s) -
Abia Rocío,
Fry Stephen C
Publication year - 2001
Publication title -
journal of the science of food and agriculture
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.782
H-Index - 142
eISSN - 1097-0010
pISSN - 0022-5142
DOI - 10.1002/jsfa.924
Subject(s) - ceratonia siliqua , proanthocyanidin , tannin , chemistry , caecum , food science , gastrointestinal tract , condensed tannin , metabolism , biochemistry , feces , sephadex , botany , polyphenol , biology , medicine , antioxidant , enzyme , microbiology and biotechnology
The aim of the work was to study the binding, degradation and metabolism of dietary condensed tannins in the gastrointestinal tract of an omnivore. Young pods of carob ( Ceratonia siliqua L) were radiolabelled by in vivo feeding of 14 CO 2 , trans ‐[U‐ 14 C]cinnamate or L ‐[U‐ 14 C]phenylalanine. [ 14 C]Proanthocyanidins (condensed tannins) were extracted with acetone/water (3:1 v/v), isolated on Sephadex LH‐20 and fed to rats by gavage. After 4 and 18 h, 90–94% of the gavaged 14 C was in the gut contents and/or faeces. Much of the gavaged 14 C (57%), predominantly that originally in tannins of high degree of polymerisation (DP), became insolubilised, mainly in the form of protein–tannin complexes. Some of the [ 14 C]tannins that remained soluble decreased in DP, especially in the small intestine and caecum. A further fraction (12% of the 14 C gavaged) underwent chemical modifications in the gut to form soluble, non‐tannin compounds. Small proportions of the 14 C were found in the liver (1.0–1.5%), urine (1–2%) and 14 CO 2 (1–2%). We conclude that proanthocyanidins are not inert within the gut but undergo various modifications which may affect the nutrition of the animal. © 2001 Society of Chemical Industry