A functional food ingredient to promote good health: soy isoflavones. Friends or foes?

Soy products are gaining interest in the health food industry, because of the increasing scientific findings proving their beneficial effects. Soy contains high amounts of proteins and lipids and many bioactive compounds like phytosterols and phytoestrogens. In particular, scientific research focuses on the last category that contains isoflavones naturally present in soy and soy foods. Many of the health benefits of soy are derived from its main isoflavones, genistein and daidzein. Despite the beneficial effects of isoflavones on health are still controversial, some epidemiological studies suggest that the consumption of soy products could play a role in the prevention of several cancers, menopausal symptoms, coronary heart disease and osteoporosis. Consequently, the industry is increasingly developing products that offer an alternative to traditional soy foods like tofu or soy milk, and precisely isoflavone concentrates and extracts for dietary supplements and new functional foods designed to provide health benefits for the consumer. In order to verify the content of the bioactive compounds of the main isoflavones (and their glicosides) in soy foods and derived dietary supplements, some analytical methods have been developed in our Laboratory of Pharmaco-Toxicological Analysis. Firstly, a capillary electrophoresis technique was selected for its high efficiency to separate numerous compounds in these complex food matrices. The development of a second method based on the use of HPLC in reversed phase mode is in progress.