COMPARISON TO OTHER METHODS
- Different analytical procedures are still used in the worldwide cranberry industry. They include chromatographic, colorimetric and gravimetric procedures. Most of these methods give inaccurate results which vary from 1 to 5-fold and may not be specific for PACs.
- The resulting mislabeling of products is a challenge for consumers who do not receive an efficacious dose of PACs and can lower consumer confidence in cranberry products targeted for health benefits.
- CHROMATOGRAPHIC: NP(Normal-Phase)-HPLC: the complexity of the cranberry A-type PAC structures does not allow the polymers to be separated, resulting in poor chromatographic resolution. Thiolysis, if included, does not fully cleave the A-type bonds. This method works well for non-cranberry products containing all B-type PACs, such as grape and chocolate.
- GRAVIMETRIC: this method, in which total PACs are chromatographically isolated and weighed, is an established method but it is expensive and time consuming.
- COLORIMETRIC: Vanillin, Bate-Smith and Euracran European Pharmacopoeia “hawthorn” methods can grossly overestimate the PAC content because other interfering compounds and the anthocyanin fraction naturally present in cranberry are also measured spectrally along with the anthocyanidins formed from the chemical hydrolysis reaction. This is not the case for the DMAC method.