Study of dielectric properties of adulterated milk concentration and freshness
Study of dielectric properties of adulterated milk concentration and freshness
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掺假牛奶浓度与新鲜度介电特性研究
DOI：
10.1088/1757-899x/225/1/012285
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发表时间：
2017
期刊：
影响因子：
--
通讯作者：
Sanjeev Kumar
中科院分区：
文献类型：
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作者：
V. Jitendra Murthy;N. Sai Kiranmai;Sanjeev Kumar
介电性质的知识可能会为牛奶的质量评估开发一种新的技术。利用X波段实验台和开放式同轴线探头技术，在室温(10~4500 MHz)和低、高频(微波频率)条件下，测量了牛奶浓度为70%~100%的稀释牛乳在22℃下储存36h和5℃下储存144h的介电性能和电导率。当频率高于约20 MHz时，原料奶的介电常数(ϵ‘)最低，而在每个频率下的损耗(ϵ“)或欺骗因子tan(δ)都最高。穿透深度(Dp)随着频率、水分含量和储存时间的减少而增加，足以检测牛奶样品的介电特性变化，并提供大规模的射频巴氏杀菌过程。损失系数可以作为预测牛奶浓度和新鲜度的指标。
The knowledge of dielectric properties may hold a potential to develop a new technique for quality evaluation of milk. The dielectric properties of water diluted cow’s milk with milk concentration from 70 percent to 100 percent stored during 36hour storage at 22°C and 144 hour at 5°C were measured at room temperature for frequencies ranging from 10 to 4500 MHz and at low, high & at microwave frequencies using X band bench and open-ended coaxial-line probe technology, along with electrical conductivity. The raw milk had the lowest dielectric constant (ϵ′) when the frequency was higher than about 20M.Hz, and had the highest loss (ϵ″) or decepation factor tan (δ) at each frequency. The penetration depth (dp) increased with decreasing frequency, water content and storage time, which was large enough to detect dielectric properties changes in milk samples and provide large scale RF pasteurization processes. The loss factor can be an indicator in predicting milk concentration and freshness.