Tecnologico de Monterrey, Escuela de Ingeniería y Ciencias, Ave. Eugenio Garza Sada 2501, Monterrey 64849, Mexico.
Dpto. Tecnología de Alimentos, Universitat Politècnica de València, Camino de Vera s/n, 46022 Valencia, Spain.
Ultrason Sonochem. 2018 Oct;47:47-56. doi: 10.1016/j.ultsonch.2018.04.019. Epub 2018 Apr 30.
Power ultrasound is applied in food technology to intensify extraction processes, due to the phenomena ultrasonic energy induces in the medium, enhancing mass transfer. The purpose of this work was the acoustic characterization of four transducers of different geometries and the evaluation of their performance in the ultrasonically assisted supercritical fluid extraction of antioxidants from oregano. The transducers differed in the amount of energy transmitted into the medium. Designs varied from the base model (T1), a larger cylindrical headmass (T2), a stepped circular section sonotrode (T3) and a multiplate configuration (T4). The highest nominal power density provided according to the calorimetric method was for T4 (151.6 ± 7.1 W/L). The T2 produced a more uniform acoustic field and a higher acoustic pressure (150.6 ± 20.5 kPa). Both parameters had an impact on total phenolics and antioxidants extraction with CO under supercritical conditions (35 MPa, 35 °C, 2.3% ethanol as co-solvent). T4 and T2 were equally efficient (4.0 ± 0.2 and 4.2 ± 0.2 mg GA/g) for phenolic extraction, and with respect to antioxidant capacity, the best performance was that of T4 (26.4 ± 1.1 μmol TE/g). Of the antioxidant compounds extracted, flavones and flavanones were identified. Therefore, transducer geometry influenced the amount and distribution of energy transmitted into the medium, thus determining the efficiency of the extraction process.
功率超声在食品技术中被应用于强化提取过程，这是由于超声能量在介质中引起的现象，增强了质量传递。本工作的目的是对四种不同几何形状的换能器进行声学特性表征，并评估它们在超声辅助超临界流体提取牛至中抗氧化剂的性能。换能器在传递到介质中的能量数量上有所不同。设计从基础模型（T1）变化，一个更大的圆柱形头部质量（T2），一个阶梯圆形截面超声变幅杆（T3）和一个多板配置（T4）。根据量热法提供的最高标称功率密度为 T4（151.6±7.1 W/L）。T2 产生更均匀的声场和更高的声压（150.6±20.5 kPa）。这两个参数都对在超临界条件下（35 MPa、35°C、2.3%乙醇作为共溶剂）用 CO 进行总酚和抗氧化剂提取有影响。T4 和 T2 在提取酚类物质方面同样有效（4.0±0.2 和 4.2±0.2 mg GA/g），而就抗氧化能力而言，T4 的性能最好（26.4±1.1 μmol TE/g）。从提取的抗氧化化合物中，鉴定出黄酮类和黄烷酮类。因此，换能器的几何形状影响传递到介质中的能量的数量和分布，从而决定了提取过程的效率。
