TY  - JOUR
A1  - Ruiz, Salome Vargas
A1  - Hass, Roland
A1  - Reich, Oliver
T1  - Optical monitoring of milk fat phase transition within homogenized fresh milk by Photon Density Wave spectroscopy
T2  - International dairy journal
N2  - Photon Density Wave (PDW) spectroscopy was applied for temperature dependent monitoring of melting and crystallization of milk fat within homogenized fresh milk. As an in-line process analytical technique, PDW spectroscopy quantifies continuously the optical properties of turbid material, providing an insight into its structural processes. Here, the measured absorption coefficients reflect temperature as well as fat content of milk and the reduced scattering coefficients probe physical changes of the light scattering fat droplets and casein micelles. Thermal processing reveals breakpoints within the temperature trend of the reduced scattering coefficient of fat containing milk. Found at 16 degrees C and 24 degrees C while cooling and heating, respectively, they are associated to the phase transitions of milk fat. Continuous isothermal measurement of the optical coefficients showed that the crystallization process requires several hours. The strongly changing reduced scattering coefficient implies that the thermal history of milk will have a major impact on any method based on light scattering as quantitative analytical technique.
Y1  - 2012
UR  - https://publishup.uni-potsdam.de/frontdoor/index/index/docId/35630
SN  - 0958-6946
VL  - 26
IS  - 2
SP  - 120
EP  - 126
PB  - Elsevier
CY  - Oxford
ER  -