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

在尼亚加拉地区，一些酿酒葡萄的收获时间是在11月至2月之间，以生产冰酒和冰糖浆。在一年中的这个时候，葡萄会积累大量的多酚，这些多酚是白藜芦醇和栎素等分子，在饮食中或作为营养补充剂时，与积极的健康结果有关。多酚积累在葡萄皮和种子中，这是生产冰酒和冰糖浆的副产品。目前，这些部分的葡萄正在被丢弃，其丰富的多酚含量没有实现任何价值。最近，我们开发了一种“绿色”提取方法来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。为了创造一种潜在的可食用产品，可以作为片剂提供，我们使用β-环糊精作为水中多酚的载体分子。多酚在水中的溶解度很低，但很容易被负载到β-环糊精中，从而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成商业规模，可以用来处理来自冬季收获的葡萄的许多吨皮/种子废料。此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，通过测试几个前处理和处理步骤来改进提取过程，以确定哪些步骤有效且成本效益高，因此可以商业化实施。然后，我们将测试几种后处理策略，以确定一种保持产品中多酚稳定性的策略。多酚会随着时间的推移而降解，特别是在受热受光的情况下。我们相信，它们在β-环糊精中的负载将防止这种可能性，但需要证明这一点。我们将使用在布罗克大学冷气候酿酒和葡萄栽培研究所进行的代谢组谱分析(即对广泛的多酚分子的测量)来评估在所有测试条件下多酚的产量和稳定性。拟议的研究将使Sweet&Sticky公司能够开发一种可以立即用于商业的工业协议。

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.