Development of improved procedures for evaluating the smoke aroma potential of grapes exposed to forest fire smoke

成熟的葡萄暴露在森林大火的烟雾中，通常会产生一种令人不快的烟熏/灰熏味（或香气），这是消费者无法接受的。这种被称为烟雾污染的现象，对加拿大的葡萄园和酿酒厂来说，问题越来越严重，因为这些葡萄园和酿酒厂往往位于森林火灾频发的地区。由于受烟熏污染的葡萄酒可能会造成重大的经济损失，因此显然需要一种风险评估策略，能够在发酵前（理想情况下，在收获前）准确地确定葡萄中烟熏味的强度。目前的测试方法采用气相色谱-质谱（GC-MS）分析技术来测试已知具有烟熏味的化合物（如愈创木酚）的存在。尽管有几家北美公司已经提供了基于gc - ms的烟雾污染测试，但这些测试的一个主要问题是，像愈创木酚这样的化合物通常储存在葡萄中，与各种糖有关。这些与糖有关的烟味化合物既不能通过GC-MS检测到，也不能通过味觉或嗅觉轻易地察觉到，然而，它们可能在发酵和老化过程中被酵母释放出来。根据我们对葡萄/葡萄酒中其他风味化合物的调节知识，我们假设大多数烟味化合物作为糖链类似物储存在葡萄中。我们建议开发一种方法，通过这种方法，葡萄中与糖相关的烟味化合物可以在不发酵的情况下快速分解，从而使现有的GC-MS方法能够检测到愈创木酚等化合物。迄今为止发表的文献中报道的影响这种分裂的条件不适合用于准确的评估目的。我们改进的方法将允许我们的公司合作伙伴，塞巴斯蒂安农场（MarkAnthony集团的一个葡萄园）在收获前评估葡萄的“烟香潜力”，使保险计划成为可能，并支持葡萄园内或酿酒厂内缓解策略的发展。该方法将与塞巴斯蒂安现有的烟雾污染评估提供商和研发设施完全兼容。

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