Departamento de Química, Universidad Técnica Particular de Loja (UTPL), Calle Marcelino Champagnat s/n, Loja 110107, Ecuador.
Molecules. 2023 Apr 27;28(9):3755. doi: 10.3390/molecules28093755.
Cocoa beans ( L.) are an important source of polyphenols. Nevertheless, the content of these compounds is influenced by post-harvest processes. In this sense, the concentration of polyphenols can decrease by more than 50% during drying. In this study, the process of procyanidins extraction was optimized and the stability of catechins, procyanidins, and theobromine to different drying temperatures was evaluated. First, the effectiveness of methanol, ethanol, acetone, and water as extract solvents was determined. A Box-Behnken design and response surface methodology were used to optimize the Microwave-Assisted Extraction (MAE) process. The ratios of methanol-water, time, and temperature of extraction were selected as independent variables, whereas the concentration of procyanidins was used as a response variable. Concerning the drying, the samples were dried using five temperatures, and a sample freeze-dried was used as a control. The quantitative analyses were carried out by HPLC-DAD-ESI-IT-MS. The optimal MAE conditions were 67 °C, 56 min, and 73% methanol. Regarding the drying, the maximum contents of procyanidins were obtained at 40 °C. To our knowledge, this is the first time that the stability of dimers, trimers, and tetramers of procyanidins on drying temperature was evaluated. In conclusion, drying at 40 °C presented better results than the freeze-drying method.
可可豆（L.）是多酚的重要来源。然而，这些化合物的含量会受到收获后处理的影响。在这种情况下，多酚的浓度在干燥过程中会减少 50%以上。在本研究中，优化了原花青素的提取工艺，并评估了儿茶素、原花青素和可可碱对不同干燥温度的稳定性。首先，确定了甲醇、乙醇、丙酮和水作为提取溶剂的效果。采用 Box-Behnken 设计和响应面法优化微波辅助提取（MAE）工艺。甲醇-水的比例、提取时间和温度被选为自变量，而原花青素的浓度则作为响应变量。关于干燥，样品在五种温度下干燥，并使用冷冻干燥的样品作为对照。采用 HPLC-DAD-ESI-IT-MS 进行定量分析。MAE 的最佳条件为 67°C、56 分钟和 73%甲醇。关于干燥，在 40°C 时获得了最高的原花青素含量。据我们所知，这是首次评估原花青素二聚体、三聚体和四聚体在干燥温度下的稳定性。总之，在 40°C 下干燥的效果优于冷冻干燥法。
