Advancing quantification methods for polyphenols in brown seaweeds-applying a selective qNMR method compared with the TPC assay.

The TPC assay provided similar polyphenolic amounts to the selective qNMR method for sublittoral species. For eulittoral growing species, the TPC method showed amounts up to three times higher than the qNMR method-most likely illustrating the lack of selectivity in the TPC assay.