生鲜牛乳的非均质性和强散射特性是影响现代分析技术精确、快速检测牛乳品质的重要原因。申请人前期研究发现，射频/微波因在牛乳中极小的散射强度和较大的穿透深度使介电谱技术在牛乳品质快速、精确分析方面具有潜在优势，但目前对部分品质指标对介电谱影响规律和机制的认识还不够深入。本项目利用开口同轴探头技术研究10MHz～4500MHz范围内生鲜牛乳品质与介电谱关联机理。重点内容如下：①探明牛乳主要理化和卫生指标对介电谱的影响规律；②从大样本实验数据中提取合格牛乳介电谱指纹特征，分析几种异常乳介电谱的特异性及匹配方法，建立基于介电谱的牛乳品质定性判别模型和主要品质指标的定量预测模型；③利用电介质物理学Maxwell-Wagner等界面极化理论揭示牛乳分散系中粒子介电行为微观机制与介电谱宏观规律间关联机理。本研究可为牛乳品质射频/微波介电谱分析提供科学依据，有助于丰富非均质液态食品在电磁场中的介电极化理论。

The nonhomogeneity and strong scattering characteristics of fresh milk are the important reasons that influence the precision and speed of milk quality detection. Our previous studies found that since the Radio-frequency (RF) or microwave (MW) has very small scattering intensity and large penetration depth in milk, the dielectric spectra has potential advantages in the rapid and accurate detection of milk quality. However, the influence rules and correlation mechanism between the partial quality indexes and the dielectric spectra of raw fresh milk are still need to be further studied. Open-ended coaxial probe technology will be used to study the correlative mechanism between milk’s qualities and dielectric spectra over the frequency range of 10MHz-4500MHz. The main objectives of this research are: ① to ascertain the influence rules of main physiochemical indexes and hygienic indexes on dielectric spectra of raw fresh milk, ② based on experimental data of large sample size, to extract the fingerprint features of dielectric spectra of qualified raw fresh milk, to study specificity and matching methods of dielectric spectra of some abnormal milk, and to develop qualitative discriminant models for identifying unqualified milk and quantitative prediction models of main quality indexes of qualified raw fresh milk based on dielectric spectra, and ③ to reveal the correlative mechanism between microscopic mechanism of dielectric behavior of particles in milk dispersion system and macroscopic rules of dielectric spectra by interfacial polarization theory such as Maxwell-Wagner in dielectric physics. This study will provide scientific basis for quality detection of milk based on RF and MW dielectric spectra, and help to enrich theories of dielectric polarization of nonhomogeneous liquid food in RF or MW electromagnetic field.