Proanthocyanidins in commercial preparations of lingonberry (Vaccinium vitis-idaea) and cranberry (Vaccinium macrocarpon).

To date there is no standard procedure for the determination of proanthocyanidins (PAC). There is thus no common base for comparisons of declared contents of various preparations. This problem was made obvious by a comparative analysis of proanthocyanidins of lingonberry (Vaccinium vitis-idaea) and cranberry (Vaccinium macrocarpon). In five commercial preparations each with lingonberry and with cranberry in comparable galenical formulation the fraction of PAC was quantified by photometric determination and by RP-HPLC with UV detection. The respective mono-, di and trimeric compounds were identified by fluorescence detection and by mass-spectrometric determination. As expected, the photometric analysis led in all cases to considerably higher PAC contents than the specific HPLC method with UV detection. Lingonberry was shown to be a rich source of proanthocyanidins: On comparison of similar galenical formulations of lingonberry and cranberry higher contents were found in favour of lingonberry preparations in almost all cases with respect to the quantitative and the qualitative composition (differentiation between A- and B-type PAC).