Optimization and metabolomic characterization of a green extraction protocol for wine grape polyphenols

在尼亚加拉地区，11月至2月期间会收获一些酿酒葡萄，用于生产冰酒和冰花。 在每年的这个时候，葡萄积累了高水平的多酚，这是像白藜芦醇和槲皮素这样的分子，当包含在饮食中或作为营养补充剂时，与积极的健康结果有关。 多酚积累在葡萄的皮和种子中，这是冰酒和冰花生产的副产品。目前，葡萄的这些部分被丢弃，并且没有从其丰富的多酚含量中实现价值。 最近，我们开发了一种“绿色”提取方案，从冬收葡萄中分离多酚，并通过测量28种不同多酚分子的水平来验证该方法。 为了创造一种可以作为片剂提供的潜在可食用产品，我们使用β-环糊精作为水中多酚的载体分子。 多酚具有非常低的水溶性，但容易加载到β-环糊精中，这使其在水中的溶解度增加数千倍。 我们现在希望将这种方法发展到商业规模，可用于处理冬季收获的葡萄的许多吨皮/种子废料。 这个应用程序详细说明了我们将使用的方法。 我们将与Sweet & Sticky和NSF International合作，通过测试几个预处理和处理步骤来改进提取过程，以确定哪些是有效和具有成本效益的，因此可以在商业上实施。 然后，我们将测试几种后处理策略，以确定保持产品中多酚稳定性的策略。 多酚可以随着时间的推移而降解，特别是如果暴露于热和光。 我们相信，将它们装载到β-环糊精中将防止这种可能性，但需要证明这一点。 我们将使用代谢组学分析（即广泛的多酚分子的测量），在布洛克大学寒冷气候酿酒和葡萄栽培研究所进行，以评估在所有测试条件下多酚的产量和稳定性。 这项研究将使Sweet & Sticky能够开发出一种可以立即投入商业使用的工业协议。

In Niagara region, some harvesting of wine grapes occurs between November and February for Ice Wine and Ice Syrup production. At this time of year, grapes have accumulated high levels of polyphenols, which are molecules like resveratrol and quercetin that have been linked to positive health outcomes when included in the diet or as nutraceutical supplements. Polyphenols accumulate in the skins and seeds of grapes, which are waste byproducts of Ice Wine and Ice Syrup production. Presently, these parts of the grapes are being discarded and no value is realized from their rich polyphenol content. Recently, we developed a 'green' extraction protocol to isolate polyphenols from winter-harvest grapes and validated the approach by measuring the levels of 28 different polyphenolic molecules. To create a potentially edible product that could be provided as a tablet, we used beta-cyclodextrin as a carrier molecule for polyphenols in water. Polyphenols have very low water solubility but are readily loaded into beta-cyclodextrin which increases their solubility in water by several thousand-fold. We now wish to develop this approach into a commercial scale that can be used to process many tonnes of skin/seed waste from winter-harvest grapes. This application details the approach we will use. In collaboration with Sweet & Sticky and NSF International, we will refine the extraction process by testing several pre-processing and processing steps to identify those that are efficacious and cost effective, and could therefore be implemented commercially. We will then test several post-processing strategies to determine one that maintains the stability of polyphenols in the product. Polyphenols can degrade over time, particularly if exposed to heat and light. We believe that their loading into beta-cyclodextrin will protect against this possibility, but need to demonstrate this. We will use metabolomic profiling (i.e. measurements of a wide range of polyphenolic molecules), performed at the Cold Climate Oenology and Viticulture Institute at Brock University, to assess the yield and stability of polyphenols under all tested conditions. The proposed studies will enable Sweet & Sticky to develop an industrial protocol that can be used commercially immediately.