Porter Assay and PROTOVIN™ Grape Seed Extract
The unit of measurement of the Porter Assay is the PVU (Porter Value Unit). The Porter Assay is a chemical test to help determine the potency of procyanidin containing compounds, such as grape seed extract. It is an acid
hydrolysis, which splits larger chain units (dimers and trimers) into single unit monomers and oxidizes them. This leads to a colour change, which can be measured using a spectrophotometer. The greater the asorbance at a certain wavelength of
light, the greater the potency. Ranges for grape seed extract are from 25 PVU for low grade material to over 300 for premium grape seed extracts. HPLC and
PROTOVIN™ Grape Seed Extract The HPLC (High Performance
Liquid Chromatography) is an analytical tool that identifies the makeup of a product such as grape seed extract. The components in a product are identified by using commercially available standards. Because there are standards for the
monomers, catechin and epicatechin, HPLC allows the determination of the % monomeric content of a grape seed extract. HPLC can also determine % gallic acid as standards are available. HPLC shows that Omega's PROTOVIN™
is a broad spectrum grape seed extract, with both monomeric and higher chain oligomeric compounds.
Conclusion
When used together the Porter Assay and HPLC are leading edge analytical methods for
the testing of grape seed extract. Omega carries out both procedures in-house, and in addition validates its data with independent laboratory analyses. In this way Omega brings the highest levels of analytical science to the marketplace,
ensuring a high quality product. |
