Abstract
The dielectric properties of adulterated raw goat’s milk with soy protein (SP) isolate powder at the SP content of 0–3.98 % were measured from 20 to 4500 MHz at 5–75 °C using an open-ended coaxial-line probe. The dielectric constant ε′ decreased as either frequency or temperature increased. The dielectric loss factor ε″ decreased with increasing frequency to a minimum between about 1000 and 3000 MHz and then increased as frequency increased. It increased with temperature below about 1000 MHz, but decreased above 3000 MHz. Both ε′ and ε″ increased linearly with increasing SP content. The permittivities of adulterated goat’s milk as functions of SP content and temperature could be accurately described by second-order polynomial models. The SP content might be predicted if the permittivities and temperature of goat’s milk are known. The study is useful to understand the dielectric properties of adulterated milk with soy protein and helpful to develop soy protein detector for milk.
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Acknowledgments
The authors gratefully acknowledge financial supports from Jiangsu Key Laboratory for Physical Processing of Agricultural Products (Project No. JAPP2014-2) and from Shaanxi Agricultural Sci-Tech Innovation and Research Grant (Project No. 2015NY001).
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Zhu, X., Kang, F. Frequency- and Temperature-Dependent Dielectric Properties of Goat’s Milk Adulterated with Soy Protein. Food Bioprocess Technol 8, 2341–2346 (2015). https://doi.org/10.1007/s11947-015-1593-x
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DOI: https://doi.org/10.1007/s11947-015-1593-x