title: Microwave dielectric spectroscopy study of water dynamics in normal and contaminated raw bovine milk.
abstract: The role of water in bovine milk is more complicated than that of a background solvent. To understand the interaction between water and the constituents of milk, an extensive dielectric study of the γ-dispersion of raw bovine milk was carried out over the frequency range 0.1-50GHz and the interval of temperatures (10°C-42°C). Samples were provided by utilizing an extended donor pool. The results reveal that the temperature dependence of the characteristic relaxation times is described by the Arrhenius law. Furthermore, it conforms to a Meyer-Neldel compensation, whereby the pre-factor of the relaxation times is dependent on the activation energy. This entropy/enthalpy compensation is traced to the interaction between bulk water dynamic clusters and other milk constituents. A statistical correlation between the Somatic Cell Count, a traditional measure of milk quality, and the relaxation times is provided as well, opening new vistas for the industrial classification of milk.
authors.affiliation: The Hebrew University of Jerusalem, Department of Applied Physics, Israel.
authors.forename: Daniel
authors.initials: D
authors.lastname: Agranovich
authors.affiliation: Ariel University, Department of Physics, Israel; The Hebrew University of Jerusalem, Department of Applied Physics, Israel.
authors.forename: Paul Ben
authors.initials: PB
authors.lastname: Ishai
authors.affiliation: Afimilk, Kibbutz Afikim, Israel.
authors.forename: Gil
authors.initials: G
authors.lastname: Katz
authors.affiliation: Afimilk, Kibbutz Afikim, Israel.
authors.forename: Dror
authors.initials: D
authors.lastname: Bezman
authors.affiliation: The Hebrew University of Jerusalem, Department of Applied Physics, Israel. Electronic address: yurif@mail.huji.ac.il.
authors.forename: Yuri
authors.initials: Y
authors.lastname: Feldman
mesh_terms: D000818:Animals; D002417:Cattle; D058266:Dielectric Spectroscopy; D004926:Escherichia coli / Q000737:chemistry / Q000254:growth & development; D005260:Female; D005506:Food Contamination / Q000032:analysis*; D008413:Mastitis / Q000175:diagnosis / Q000382:microbiology / Q000662:veterinary*; D008872:Microwaves; D008892:Milk / Q000737:chemistry* / Q000382:microbiology; D013291:Streptococcus / Q000737:chemistry / Q000254:growth & development; D013696:Temperature; D013816:Thermodynamics; D014867:Water / Q000032:analysis*
chemical_list: D014867:Water
keywords: Bovine milk; Conductivity; Dielectric relaxation; Dielectric spectroscopy; Mastitis; Meyer-Neldel compensation; Somatic cell count; Water