Dielectric spectroscopy study of water dynamics in frozen bovine milk.
Bovine milk is a complex colloidal liquid exhibiting a multi-scaled structure. It is of particular importance, both commercially and scientifically, to investigate both its dynamic and structural properties. In the current study we have employed the broadband dielectric spectroscopy (BDS) technique in the frequency range of 10(-1)-10(6)Hz and the temperature range of 176-230 K in order to examine the molecular structure and dynamics of quenched bovine milk. Four dielectric relaxation processes were identified. Three of them are associated with water in its different forms: water-lactose complexes, bulk hexagonal and cubic ices. The fourth process is attributed to domain wall relaxations linked to the presence of micro-cracks in the ice structures. In addition, the first process, attributed to water-lactose complexes, obeys the Meyer-Neldel compensation law and can be taken as evidence of differing interfaces of these complexes with the bulk water of the milk, mediated by the lactose concentration. Furthermore, an intriguing structural-dynamic transition around 200K was observed. Considering the mentioned above, we conclude that our results emphasize the structural and dynamical significance of water in bovine milk.
['Agranovich|Daniel|D|', 'Ben Ishai|Paul|P|', 'Katz|Gil|G|', 'Bezman|Dror|D|', 'Feldman|Yuri|Y|']
D000465:Algorithms D000818:Animals D002364:Caseins D002417:Cattle D003102:Colloids D058266:Dielectric Spectroscopy D019277:Entropy D005615:Freezing D006358:Hot Temperature D007700:Kinetics D007785:Lactose D008892:Milk D044366:Transition Temperature D014867:Water
Dielectric spectroscopy Water Bovine milk Dielectric relaxation Ice Lactose