CSIRO Food and Nutritional Sciences, 671 Sneydes Road, Werribee, VIC 3030, Australia.
Ultrason Sonochem. 2013 Jan;20(1):52-62. doi: 10.1016/j.ultsonch.2012.07.018. Epub 2012 Aug 8.
Recent research has shown that high frequency ultrasound (0.4-3 MHz), can enhance milkfat separation in small scale systems able to treat only a few milliliters of sample. In this work, the effect of ultrasonic standing waves on milkfat creaming was studied in a 6L reactor and the influence of different frequencies and transducer configurations in direct contact with the fluid was investigated. A recombined coarse milk emulsion with fat globules stained with oil-red-O dye was selected for the separation trials. Runs were performed with one or two transducers placed in vertical (parallel or perpendicular) and horizontal positions (at the reactor base) at 0.4, 1 and/or 2 MHz (specific energy 8.5 ± 0.6 kJ/kg per transducer). Creaming behavior was assessed by measuring the thickness of the separated cream layer. Other methods supporting this assessment included the measurement of fat content, backscattering, particle size distribution, and microscopy of samples taken at the bottom and top of the reactor. Most efficient creaming was found after treatment at 0.4 MHz in single and double vertical transducer configurations. Among these configurations, a higher separation rate was obtained when sonicating at 0.4 MHz in a vertical perpendicular double transducer setup. The horizontal transducer configuration promoted creaming at 2 MHz only. Fat globule size increase was observed when creaming occurred. This research highlights the potential for enhanced separation of milkfat in larger scale systems from selected transducer configurations in contact with a dairy emulsion, or emulsion splitting in general.
最近的研究表明，高频超声波（0.4-3 MHz）可以增强小规模系统中的乳脂分离能力，这些系统只能处理几毫升的样品。在这项工作中，研究了超声驻波对乳脂分离的影响，使用 6L 反应器，并研究了与流体直接接触的不同频率和换能器配置的影响。选择重组的粗牛奶乳液，其中脂肪球用油红-O 染料染色，用于分离试验。在 0.4、1 和/或 2 MHz（每个换能器的比能量为 8.5 ± 0.6 kJ/kg）下，通过将一个或两个换能器放置在垂直（平行或垂直）和水平位置（在反应器底部）来运行。通过测量分离的奶油层的厚度来评估奶油分离行为。支持此评估的其他方法包括测量脂肪含量、背散射、粒度分布以及从反应器底部和顶部取出的样品的显微镜检查。在单和双垂直换能器配置下，在 0.4 MHz 下处理时发现最有效的奶油分离。在这些配置中，在垂直垂直双换能器设置中以 0.4 MHz 超声处理时，分离速率更高。仅在 2 MHz 时，水平换能器配置会促进奶油分离。当发生奶油分离时，观察到脂肪球尺寸增加。这项研究强调了从选定的换能器配置接触乳制品乳液或乳液分裂的角度出发，在更大规模的系统中增强乳脂分离的潜力。
