Determination of plant polyphenols in Danish foodstuffs by HPLC-UV and LC-MS detection

To estimate the contents of flavonoids in the Danish diet, we have used a high performance liquid chromatographic method for the analysis of fruits, vegetables and beverages. The flavonoid contents were quantified, and the observations were verified by mass spectrometry. The investigation is not completed, but we are able to give an preliminary estimate of the daily flavonoid intake at 26 mg/day. The major food contributors are tea, onions, apples, oranges, and orange juice. Other food subjects have high flavonoid contents, but the daily intake is low, so their contributions to the average daily intake are negligible.