HPLC Effective Test for Bilberry

QUEENSLAND, Australia — A high performance liquid chromatography (HPLC) method detected adulteration in one commercial bilberry (V. myrtillus) extract and while confirming Mirtoselect® compliance with containing 25 percent bilberry as claimed. Published in the Journal of Agricultural and Food Chemistry (54, 19:7378-82, 2006), the study compared the anthocyanin content in Mirtoselect (from Indena) bilberry with another commercial bilberry extract. Using the single-wavelength UV-visible spectrophotometric method, described in the British Pharmacopoeia, the total anthocyanin content of both extracts was similar to the value claimed by the manufacturers (25 percent). When HPLC was used, Mirtoselect contained 25 percent bilberry anthocyanins while the second extract contained only 9 percent anthocyanins. Results suggest that the adulterated extract did not contain any bilberry; rather it contained chemicals not easily detected with UV methods. Researchers concluded detection of deliberate adulteration in commercial samples thus requires the use of alternative, more sophisticated methods of analysis—such as HPLC—with photodiode array detection as a minimum. Commenting on the study, Roberto Pace, Indena analytical research director said, “These important results confirm the suitability of the analytical method in identifying unequivocally the botanical raw materials used for manufacturing and evaluating the composition of the extracts.”