Understanding of phenolic extraction during fermentation has long been limited to either empirical studies or well-mixed models, which limits the ability to predict the impact of winemaking decisions on final wine phenolic profile. We have developed a combined phenolic extraction and fermentation model that accounts for the heterogeneous nature of red wine fermentations and fermentor geometry by combining previously derived and validated red wine models. Here, we apply this model to explore the impact of fermentor volume and cap management on anthocyanin, skin tannin, and seed tannin extraction. Results indicate that larger, hotter fermentors favor faster extraction, and pump-over frequency strongly affects extraction of anthocyanins, skin tannins, and the relative contribution of seed and skin tannins. At small scales, this variation was not observed, in agreement with experiments. These results suggest potential winemaking strategies to control the ratio of skin to seed tannins in the final wine. Additionally, we explored the impact of fermentor geometry on anthocyanin extraction in the absence of cap management. The ratio of cap surface area to bulk liquid volume was critical in determining the concentration of anthocyanins in the bulk liquid, shedding light on conflicting small- and large-scale results of liquid anthocyanin concentrations without cap management.

中文翻译：

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使用反应器工程模型预测发酵罐几何形状和瓶盖管理对酚类剖面的影响

长期以来，对发酵过程中酚类提取的理解仅限于经验研究或混合良好的模型，这限制了预测酿酒决策对最终葡萄酒酚类成分影响的能力。我们开发了一种酚类提取和发酵组合模型，通过结合先前派生和验证的红葡萄酒模型，该模型解释了红葡萄酒发酵和发酵罐几何结构的异质性。在这里，我们应用该模型来探索发酵罐容积和瓶盖管理对花青素、皮单宁和种子单宁提取的影响。结果表明，更大、更热的发酵罐有利于更快的提取，泵送频率强烈影响花青素、皮单宁的提取以及种子和皮单宁的相对贡献。在小范围内，没有观察到这种变化，与实验一致。这些结果表明了潜在的酿酒策略，以控制最终葡萄酒中皮与籽单宁的比例。此外，我们探索了在没有瓶盖管理的情况下发酵罐几何形状对花青素提取的影响。菌盖表面积与本体液体体积的比率对于确定本体液体中花青素的浓度至关重要，揭示了在没有菌盖管理的情况下液体花青素浓度的小规模和大规模结果相互矛盾。