BACKGROUND:Blueberries contain large amounts of phenolic compounds as well as a higher concentration of anthocyanins than other berries. The peel of these fruits contains most of the anthocyanins and therefore pomace is left with the largest quantity of valuable phenolic compounds. Extraction is the most critical step to obtain such compounds. OBJECTIVE:This study aims to optimize the extraction of polyphenols and antioxidant compounds from blueberry pomace by solid-liquid extraction (SLE) and microwave-assisted extraction (MAE). METHODS:A Pareto chart was used to confirm the factor with the highest impact, response surface for analyzing the effect of extraction conditions on total phenol content (TPC) (through Folin-Ciocalteu), total anthocyanin content (TAC) (through differential pH), antioxidant capacity (AC) (through DPPH assay) and the Box-Behnken matrix to determine the optimal conditions for marc extraction with each method. RESULTS:Ethanol concentration is an impact factor for both methods, as well as irradiation method, radiation power for MAE and temperature for SLE. Regarding SLE and MAE extraction, under optimal conditions, a TCP content of 335.95 and 426.19 (mg GAE/100 g), TAC 272.69 and 389.64 (mg Cyn-3-glu/100 g), and CA 528.96 and 654.11 (mg TE/100 g) was obtained, respectively. CONCLUSIONS:The performance of phenolic compound extraction via MAE method is better than that of SLE.

中文翻译：

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响应面法优化蓝莓果渣多酚及抗氧化化合物常规固液萃取和微波辅助萃取

背景：蓝莓含有大量酚类化合物以及比其他浆果更高浓度的花青素。这些水果的果皮含有大部分花青素，因此果渣中含有最多的有价值的酚类化合物。提取是获得此类化合物的最关键步骤。目的：本研究旨在优化固液萃取（SLE）和微波辅助萃取（MAE）从蓝莓果渣中提取多酚和抗氧化化合物的工艺。方法：使用帕累托图确认影响最大的因素，响应面分析提取条件对总酚含量 (TPC)（通过 Folin-Ciocalteu）、总花青素含量（TAC）（通过差异 pH）的影响, 抗氧化能力 (AC)（通过 DPPH 测定）和 Box-Behnken 矩阵，以确定每种方法提取渣滓的最佳条件。结果：乙醇浓度是两种方法的影响因素，以及辐照方法、MAE的辐射功率和SLE的温度。关于 SLE 和 MAE 提取，在最佳条件下，TCP 含量为 335.95 和 426.19（mg GAE/100 g）、TAC 272.69 和 389.64（mg Cyn-3-glu/100 g）以及 CA 528.96 和 654.11（mg TE/分别获得 100 g)。结论:MAE法提取酚类化合物的性能优于SLE法。关于 SLE 和 MAE 提取，在最佳条件下，TCP 含量为 335.95 和 426.19（mg GAE/100 g）、TAC 272.69 和 389.64（mg Cyn-3-glu/100 g）以及 CA 528.96 和 654.11（mg TE/分别获得 100 g)。结论:MAE法提取酚类化合物的性能优于SLE法。关于 SLE 和 MAE 提取，在最佳条件下，TCP 含量为 335.95 和 426.19（mg GAE/100 g）、TAC 272.69 和 389.64（mg Cyn-3-glu/100 g）以及 CA 528.96 和 654.11（mg TE/分别获得 100 g)。结论:MAE法提取酚类化合物的性能优于SLE法。