ANALYSIS OF FLAVANOLS IN BEVERAGES BY HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY WITH CHEMICAL-REACTION DETECTION

A screening method, which allows the simple and rapid determination of the flavanolic composition of plant and food extracts, has been devel oped. The method is based on a postcolumn chemical reaction with p-dim ethylaminocinnamaldehyde with detection at 640 nm after HPLC separatio n and measurement of the UV absorbance at 280 nm in a diode array dete ctor. This approach allows one not only to obtain the flavanol profile s of the samples but also to characterize;the compounds present in the chromatograms through their A(640)/A(280) absorbance ratio combined w ith the retention time and the UV spectrum. The advantages of this pro cedure are shown by applying it to the study of the flavanol compositi on of some beverages, including red wine, beer, apple cider, and sour cherry and blackthorn fruit liqueurs.