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 developed. The method is based on a postcolumn chemical reaction with p-dimethylaminocinnamaldehyde with detection at 640 nm after HPLC separation and measurement of the UV absorbance at 280 nm in a diode array detector. This approach allows one not only to obtain the flavanol profiles of the samples but also to characterize the compounds present in the chromatograms through their A₆₄₀/A₂₈₀ absorbance ratio combined with the retention time and the UV spectrum. The advantages of this procedure are shown by applying it to the study of the flavanol composition of some beverages, including red wine, beer, apple cider, and sour cherry and blackthorn fruit liqueurs.