In order to validate the oxidation hypothesis of tannin development, and address our goal: Measure the presence of oxidized tannins in seeds, we are investigating methods to directly measure the initial oxidation produce of phenols, quinones. One method using a redox titration did not yield any oxidation product, and an attempt to directly observe quinones by NMR spectroscopy did not show any quinones present. The lack of response may be due to the low sensitivity of these two methods, so a third, and much more sensitive method is now being tested. It involves the production of a reaction product, phenazine, which is totally specific for the presence of ortho-phenols, the expected phenol in seed tannins. We are synthesizing a standard phenazine and will apply this method to testing for quinones in tannins. This method should be simple enough to apply in winery laboratories.
/wp-content/uploads/2017/09/AFV-Header-Logo.png 0 0 AVF /wp-content/uploads/2017/09/AFV-Header-Logo.png AVF2002-10-17 11:59:332017-10-17 12:01:09The Extraction of Condensed Tannins in Red Wine Production