Grant: Engage Grants for Universities

Ripening grapes exposed to forest fire smoke often yield wines that are characterized by an unpleasant_x000D_ smoky/ashy flavor (or aroma) that is unacceptable to consumers. This phenomenon, called smoke-taint, is_x000D_ increasingly problematic for Canada's vineyards and wineries since these are often located in regions prone to_x000D_ frequent, intense forest fires. Given the potential for significant financial losses due to smoke-tainted wines,_x000D_ there is an obvious need for risk assessment strategies that can accurately determine the intensity of smoky_x000D_ flavor in grapes before fermentation (and, ideally, harvest). Current testing methods employ an analytical_x000D_ technique known as gas chromatography-mass spectrometry (GC-MS) to test for the presence of compounds_x000D_ (like guaiacol) known to have a smoky flavor. Although several North American companies already provide_x000D_ GC-MS-based smoke-taint tests, a major problem with these tests is that compounds like guaiacol are often_x000D_ stored in grapes linked to various sugars. These sugar-linked, smoke-flavoured compounds are neither_x000D_ detectible by GC-MS nor are they easily perceptible by taste or smell, however, they maybe released by the_x000D_ yeast during fermentation and possibly ageing. Based on our knowledge of the regulation other flavour_x000D_ compounds in grapes/wines, it is hypothesized that the majority of smoke-flavoured compounds are stored_x000D_ within grapes as their sugar-linked analogues. We are proposing to develop procedures by which the_x000D_ sugar-linked smoke-flavoured compounds in grapes can be rapidly cleaved, without fermentation, to enable_x000D_ compounds like guaiacol to be detected by existing GC-MS methods. The conditions to effect such cleavage_x000D_ that have been reported in the literature published to date are not suitable to be used for accurate assessment_x000D_ purposes. Our improved method will permit our company partner, Sebastian Farms (a vineyard in the Mark_x000D_ Anthony Group) to assess the "smoke-aroma potential" of grapes before harvest, enabling insurance planning,_x000D_ and supporting the development of in-vineyard or in-winery mitigation strategies. The method will be fully_x000D_ compatible with Sebastian's existing smoke-taint assessment providers and R&D facilities.