T. Lapidot et al., BIOAVAILABILITY OF RED WINE ANTHOCYANINS AS DETECTED IN HUMAN URINE, Journal of agricultural and food chemistry, 46(10), 1998, pp. 4297-4302
Anthocyanins, which are natural plant pigments from the flavonoid fami
ly, represent substantiated constituents of the human diet. Many foods
but especially red grapes and wines contain large amounts of flavonoi
ds, which are mostly anthocyanins. The aim of our study was to determi
ne the potential bioavailability, in human, of several anthocyanins fr
om red wine. Six healthy, fasting volunteers, having a polyphenols-fre
e diet, drank 300 mL of water every hour for 12 h and collected urine.
Several weeks later, the same volunteers repeated the same procedure
but replaced the water of the fourth drinking dose with white wine. Tw
o weeks later, they repeated the procedure with red instead of white w
ine. In the 300 mt dose of red wine, the subjects received 218 mg of a
nthocyanins, which were detected in their urine by HPLC analysis with
a photodiode array detector. Two of the compounds found among the wine
anthocyanins were found unchanged in the urine. Other anthocyanin com
pounds, which seemed to have undergone molecular modifications, were d
etected in the urine after incubation with HCl. The anthocyanin level
in the urine reached a peak within 6 h of the wine drinking. Within 12
h of the wine drinking, we found 1.5-5.1% of the ingested anthocyanin
s, in the urine.