Abstract Ultrasonic-assisted extraction (UAE) was performed to extract the total phenolic compounds from avocado (Persea americana Mill. var. Drymifolia; Lauraceae) leaves with different electric powers (UAE 0%, UAE 60%, and UAE 100%) and extraction times. Ultrasonic extraction parameters were optimized by using a mathematical model made by stepwise regression (SWR) for the determination of the maximum total phenolic content (TPC) and their antioxidant activity. Moreover, TPC extraction was modeled applying heterogeneous models to elucidate the involved mechanisms phenomena that determine the extraction rates. Optimization results found that the maximum value of TPC reached 48,732 mg GAE/100 g D.M. at 84.5% electric power and 29.7 min of extraction, which was superior to 0% electric power UAE. It was also found that the ultrasound causes the degradation of phenolic compounds, whereas the final extraction yield of TPC increases and their antioxidant activity decreased with the increase of ultrasound electric power. Proposed models gave a satisfactory quality of fit data using a second-order reaction for the degradation kinetics of TPC under ultrasound application. The estimated effective diffusivity values were in a range from 1.3889 × 10−11 m2/s to 2.2128 × 10−11 m2/s for the UAE 0% and UAE 100%, respectively. UAE significantly increased the extraction yield through the enhancement of the effective diffusivity, demonstrating that it is a promising technology to extract phenolic substances from avocado leaves.

中文翻译：

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超声波辅助从鳄梨叶（Persea americana Mill. var. Drymifolia）中提取酚类化合物：优化和建模

摘要 采用超声波辅助提取法（UAE）从不同电功率（UAE 0%、UAE 60%、UAE 100%）的鳄梨（Persea americana Mill. var. Drymifolia; Lauraceae）叶中提取总酚类化合物并提取。次。通过使用逐步回归 (SWR) 建立的数学模型优化超声提取参数，以确定最大总酚含量 (TPC) 及其抗氧化活性。此外，应用异构模型对 TPC 提取进行建模，以阐明决定提取率的相关机制现象。优化结果发现，在 84.5% 的电功率和 29.7 分钟的提取时间下，TPC 的最大值达到 48,732 mg GAE/100 g DM，优于 0% 电功率的阿联酋。还发现超声引起酚类化合物的降解，而TPC的最终提取率随着超声功率的增加而增加，其抗氧化活性降低。提出的模型使用二阶反应为超声应用下的 TPC 降解动力学提供了令人满意的拟合数据质量。对于阿联酋 0% 和阿联酋 100%，估计的有效扩散率值分别在 1.3889 × 10−11 m2/s 到 2.2128 × 10−11 m2/s 的范围内。阿联酋通过提高有效扩散率显着提高了提取率，表明从鳄梨叶中提取酚类物质是一种很有前途的技术。而随着超声功率的增加，TPC的最终提取率增加，抗氧化活性降低。提出的模型使用二阶反应为超声应用下的 TPC 降解动力学提供了令人满意的拟合数据质量。对于阿联酋 0% 和阿联酋 100%，估计的有效扩散率值分别在 1.3889 × 10−11 m2/s 到 2.2128 × 10−11 m2/s 的范围内。阿联酋通过提高有效扩散率显着提高了提取率，表明从鳄梨叶中提取酚类物质是一种很有前途的技术。而随着超声功率的增加，TPC的最终提取率增加，抗氧化活性降低。提出的模型使用二阶反应为超声应用下的 TPC 降解动力学提供了令人满意的拟合数据质量。对于阿联酋 0% 和阿联酋 100%，估计的有效扩散率值分别在 1.3889 × 10−11 m2/s 到 2.2128 × 10−11 m2/s 的范围内。阿联酋通过提高有效扩散率显着提高了提取率，表明从鳄梨叶中提取酚类物质是一种很有前途的技术。对于阿联酋 0% 和阿联酋 100%，估计的有效扩散率值分别在 1.3889 × 10−11 m2/s 到 2.2128 × 10−11 m2/s 的范围内。阿联酋通过提高有效扩散率显着提高了提取率，表明从鳄梨叶中提取酚类物质是一种很有前途的技术。对于阿联酋 0% 和阿联酋 100%，估计的有效扩散率值分别在 1.3889 × 10−11 m2/s 到 2.2128 × 10−11 m2/s 的范围内。阿联酋通过提高有效扩散率显着提高了提取率，表明从鳄梨叶中提取酚类物质是一种很有前途的技术。