SCC和流动对牛乳射频/微波介电驰豫特征的影响及关联机制解析

实时监测挤奶管内牛乳体细胞数（SCC）并预警隐性乳房炎是养殖业和乳品安全面临的重大难题。射频/微波介电谱技术是实现牛乳SCC在线监测的优势途径，但介电谱与SCC关联机理以及管内流场的影响机制尚不清楚。我们发现，流动牛乳的介电参数（ε′和ε″）值及其介电测量重复性均高于静止牛乳，因此推测流场丰富了电磁场中牛乳的介电弛豫信息，进而强化SCC与介电谱关联。本研究运用电介质物理学理论探明牛乳SCC与射频/微波介电谱的关联机理，解析乳浆和球壳粒子的介电谱贡献机制；研究不同流速下牛乳介电驰豫特征和介电测量重复性，以Hanai方程和多物理场仿真解析流动对多分散相的极化影响机制；揭示挤奶管内脉动流状态下不同牛乳SCC等级对介电谱的影响规律和关联机制，探索牛乳SCC在线监测新方法。项目通过介电驰豫特征解析和多物理场仿真为牛乳SCC在线监测奠定基础，对拓展和创新射频/微波技术在食品领域的应用具有重要理论价值。

Real-time monitoring somatic cell count (SCC) of milk in milking pipe and early warning on subclinical mastitis are major tough problems in dairy farming and dairy safety. Radio-frequency/microwave dielectric spectroscopy is a more competitive way to monitor SCC of milk on-line, but the correlation mechanism between dielectric spectroscopy and SCC as well as the influence mechanism by flow field in pipe are still unclear. We found that the values of dielectric parameters (ε′ and ε″) and the repeatability of dielectric measurements of milk under flow state were much higher than those under static state. Therefore we speculate that the flow field enriches the dielectric relaxation information of milk in electromagnetic field, which strengthens the correlation between SCC and dielectric spectra. In this study, the theory of dielectric physics will be used to explore the correlation mechanism between SCC and radio-frequency/microwave dielectric spectra of milk and to analyze the contribution mechanism of milk plasma and spherical shell particles to dielectric spectra. The dielectric relaxation characteristics of milk and the repeatability of dielectric measurement at different flow velocities will be studied. The mechanism of polarization effect of flow on polydisperse phase will be analyzed by using the Hanai equation and multi-physical field simulation. The effect and mechanism of different SCC levels on dielectric spectra of milk in milking pipe under pulsating flow conditions will be revealed to explore a new method for on-line monitoring SCC of milk. This project will lay the foundation for on-line monitoring SCC of milk through dielectric relaxation characteristic analysis and multi-physical field simulation, which has important theoretical value and innovation to expand the application of radio-frequency/microwave technology in the field of food science.