Monitoring and Characterization of Milk Fouling on Stainless Steel Using a High-Pressure High-Temperature Quartz Crystal Microbalance with Dissipation
Monitoring and Characterization of Milk Fouling on Stainless Steel Using a High-Pressure High-Temperature Quartz Crystal Microbalance with Dissipation
复制标题
使用具有耗散的高压高温石英晶体微天平监测和表征不锈钢上的牛奶污垢
DOI：
10.1021/acs.langmuir.2c00419
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发表时间：
2022
期刊：
影响因子：
3.9
通讯作者：
Heldman, Dennis R.
中科院分区：
文献类型：
--
作者：
Huellemeier, Holly A.;Eren, Necla M.;Payne, Taylor D.;Schultz, Zachary D.;Heldman, Dennis R.
在许多工业部门，包括石油和天然气、生物医学设备和食品行业，界面上的污染恶化了过程的效率和卫生。在食品工业中，复杂的食品基质对加热的不锈钢表面的污染会增加加热阻力、泵送要求和清洁操作的频率，从而降低生产效率。本文利用石英晶体耗散微天平(QCM-D)研究了高温(135°C)下不同流量和蛋白质浓度下牛奶在不锈钢表面的污垢界面。随后，在清洗污物的过程中记录QCM-D反应。确定了结垢的两个阶段。在第一阶段，污垢速率取决于流量，而在第二阶段，污垢速率取决于流量和蛋白质浓度。在清洗过程中，较高流量下沉积的污垢比较低流量下沉积的污垢膨胀得更多。污垢沉积物的组成既有蛋白质又有矿物质。在两种流速下，都发现了两种磷酸钙的晶相：β-磷酸三钙和羟基磷灰石。在QCM-D传感器表面观察到了表面的分层现象，当沉积速度为0.2mL/min时为脆性和裂纹状结构，而在0.1mL/min时为光滑紧密堆积的结构。这些组成和形貌上的分层与不同流速下反应时间和流动动力学的差异有关。QCM-D在复杂食品系统中的高温应用照亮了蛋白质、矿物质和不锈钢表面之间的初始相互作用，否则在QCM-D的低温应用中或在较大的工作台和工业规模上可能无法检测到。本文介绍的方法和结果对优化工艺方案具有重要意义，这些方案可以限制污垢的形成，同时还可以在清洗过程中加强清除。
Fouling at interfaces deteriorates the efficiency and hygiene of processes within numerous industrial sectors, including the oil and gas, biomedical device, and food industries. In the food industry, the fouling of a complex food matrix to a heated stainless steel surface reduces production efficiency by increasing heating resistance, pumping requirements, and the frequency of cleaning operations. In this work, quartz crystal microbalance with dissipation (QCM-D) was used to study the interface formed by the fouling of milk on a stainless steel surface at different flow rates and protein concentrations at high temperatures (135 °C). Subsequently, the QCM-D response was recorded during the cleaning of the foulant. Two phases of fouling were identified. During phase-1, the fouling rate was dependent on the flow rate, while the fouling rate during phase-2 was dependent on the flow rate and protein concentration. During cleaning, foulants deposited at the higher flow rate swelled more than those deposited at the lower flow rate. The composition of the fouling deposits consisted of both protein and mineral species. Two crystalline phases of calcium phosphate, β-tricalcium phosphate and hydroxyapatite, were identified at both flow rates. Stratification in topography was observed across the surface of the QCM-D sensor with a brittle and cracked structure for deposits formed at 0.2 mL/min and a smooth and close-packed structure for deposits formed at 0.1 mL/min. These stratifications in the composition and topography were correlated to differences in the reaction time and flow dynamics at different flow rates. This high-temperature application of QCM-D to complex food systems illuminates the initial interaction between proteins and minerals and a stainless steel surface, which might otherwise be undetectable in low-temperature applications of QCM-D or at larger bench and industrial scales. The methods and results presented here have implications for optimizing processing scenarios that limit fouling formation while also enhancing removal during cleaning.