Hydrothermal extraction of green coffee beans was examined by using a semi-batch type apparatus and an optical cell for extracting beneficial compounds. Extraction curves were evaluated across varying temperatures (373–523 K) and pressures (0.6–2.1 MPa). At 473 K, increasing pressure enhanced the extraction of caffeoylquinic acids (CQAs), total phenolic content (TPC), antioxidant capacity (AOC), and caffeine. At 2.1 MPa, TPC remained constant with temperature, while AOC, CQAs, and caffeine initially increased then decreased at higher temperatures. Direct observations confirmed high temperature promoted extraction. An extraction model was proposed to account for decomposition of components at high temperatures, effectively reproducing experimental curves. This model estimated equilibrium values and rate constants representing initial extraction rate. The obtained results indicate that adjusting temperature, extraction time, and pressure can control extract composition during hydrothermal extraction of green coffee beans.

中文翻译：

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温度和压力对生咖啡豆水热提取动力学的影响


通过使用半间歇式设备和用于提取有益化合物的光学池来检查生咖啡豆的水热提取。在不同的温度（373-523 K）和压力（0.6-2.1 MPa）下评估萃取曲线。在 473 K 下，增加压力可增强咖啡酰奎尼酸 (CQA)、总酚含量 (TPC)、抗氧化能力 (AOC) 和咖啡因的提取。在 2.1 MPa 下，TPC 随温度变化保持恒定，而 AOC、CQA 和咖啡因在较高温度下先增加然后减少。直接观察证实高温促进了提取。提出了一种提取模型来解释高温下组分的分解，有效地再现实验曲线。该模型估计了代表初始提取速率的平衡值和速率常数。结果表明，调节温度、提取时间和压力可以控制生咖啡豆水热提取过程中的提取物成分。