In a bid to validate different soy isoflavone testing methods around the world, newly merged Dutch ingredients company, Acatris, a subsidiary of Royal Schouten Group, worked with TNO Nutrition and Food Research to perform a ring test with a total of 22 laboratories from around the world.
Laboratories were asked to analyse the level of isoflavones in duplicate samples of three soy preparations using their laboratories current method of analysis as well as to submit their method of analysis for further statistical comparisons.
Twenty laboratories used an HPLC method, one laboratory used an enzyme-linked immunosorbent assay (ELISA), and the last used capillary electrophoresis.
Although the results were positive for the laboratories' ability to duplicate the same results twice, the variation between the laboratories' results were statistically unacceptable, writes Acatris in a statement this week.
Reasons proposed include variations in the method of analysis such as differences in the extraction conditions, differences in the molar extinction coefficients used to calculate isoflavone values, and an unknown purity of the standards used to compare the soy isoflavones.
Last December the Association of Official Analytical Communities (AOAC) developed a soy isoflavone testing method for food. Acatris maintains that a major issue hitting the industry today is whether or not this method should be adopted, and if so, by who. This method, Acatris continues, does not address measuring isoflavone levels in biological systems so it remains to be seen whether or not soy researchers will adopt it or continue to use their own various methods.
Acatris was recently formed by mother company Royal Schouten Group through the merger of food and health companies Daminco, Orffa Health & Nutrition, Schouten USA and SoyLife Nederland,