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Anthocyanins are glycosilatd polyhydroxy and polymethoxy derivatives of 2-phenylbenzopyrylium salts. They can have one, two or more glycoside residues. Since anthocyainidins (aglycone forms) have been shown to be unstable in water and much less soluble than anthocyanins, glycosilation is assumed to confer solubility and stability to the pigment.1
On the other hand, in feeding studies using whole foods, nonacylated anthocyanins are shown to be more bioavailable than their acylated counterparts.2
The fate of the anthocyanins and other polyphenolic substances inside the living organism seems to be partial hydrolysis and / or absorption in the stomach, partial absorption in the small intestine and partial degradation by colonic microflora producing a wide array of secondary metabolites. After ingestion, some can be found on plasma and others in the organs tissues (liver, kidney).3
Relatively low concentrations of anthocyanins in plasma may be adequate to affect signal transduction and/or gene expression.4 Some experiments have also demonstrated the increase on plasma antioxidant capacity.5
1 Markakis, Pericles. Anthocyanins as food colors. Food Science and Technology. A series of monographs. Academic Press. New York, 1982.
2 Craig S. Charron, Anne C. Kurilich, Beverly A. Clevidence, Philipp W. Simon, Dawn J. Harrison, Steven J. Britz, David J. Baer, and Janet A. Novotny Bioavailability of purple carrot anthocyanins is influenced by acylation but not plant matrix effects FASEB J. 23: 729.6
3 Takashi Ichiyanagi, et al. Bioavailability and Tissue Distribution of Anthocyanins in Bilberry (Vaccinium myrtillus L.) Extract in Rats Journal of Agricultural and Food Chemistry 2006 54 (18), 6578-6587
4 Milbury, Paul E., Vita, Joseph A., Blumberg, Jeffrey B. Anthocyanins are Bioavailable in Humans following an Acute Dose of Cranberry Juice J. Nutr. 2010 140: 1099-1104
5 Talavéra, Séverine. Bioavailability of a bilberry anthocyanin extract and its impact on plasma antioxidant capacity in rats. Journal of the Science of Food and Agriculture. Volume 86, Number 1, 15 January 2006. pp. 90-97(8)
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