TY - JOUR
T1 - Physical properties and storage stability of reverse osmosis skim milk concentrates
T2 - effects of skim milk pasteurisation, solid content and thermal treatment
AU - Christiansen, Morten Vormsborg
AU - Pedersen, Troels Bjerregaard
AU - Brønd, Jesper Nagstrup
AU - Skibsted, Leif H.
AU - Ahrné, Lilia
PY - 2020
Y1 - 2020
N2 - Concentrated dairy products are of increasing interest within the dairy industry. Skim milk concentrates can be produced by reverse osmosis membrane filtration, which can be considered a non-thermal process. Therefore, the physical properties of concentrates differ from the properties of concentrates produced by evaporation. In this study, reverse osmosis filtration of raw and pasteurised skim milk was carried out in batch up to 28% total solids content and the effect of thermal treatment (65–110 °C, 15 s) and storage at 5 °C up to ten days on rheological and physical properties of concentrates, were evaluated. Concentrates produced from pasteurised skim milk required longer concentration times and showed larger average casein micelle sizes, but limited structure build-up capability during storage compared to concentrates produced from raw milk which more readily created structural networks between the milk constituents and consequently had higher viscosity. Thermal treatment of concentrates increased their average particle size and viscosity, an effect enhanced by increasing the total solids content. Concentrates produced from non-pasteurised milk showed the strongest shear-thinning behaviour during storage. Thus, the thermal treatment of milk before or after the concentration process, controls the structure formation of skim milk concentrates during storage.
AB - Concentrated dairy products are of increasing interest within the dairy industry. Skim milk concentrates can be produced by reverse osmosis membrane filtration, which can be considered a non-thermal process. Therefore, the physical properties of concentrates differ from the properties of concentrates produced by evaporation. In this study, reverse osmosis filtration of raw and pasteurised skim milk was carried out in batch up to 28% total solids content and the effect of thermal treatment (65–110 °C, 15 s) and storage at 5 °C up to ten days on rheological and physical properties of concentrates, were evaluated. Concentrates produced from pasteurised skim milk required longer concentration times and showed larger average casein micelle sizes, but limited structure build-up capability during storage compared to concentrates produced from raw milk which more readily created structural networks between the milk constituents and consequently had higher viscosity. Thermal treatment of concentrates increased their average particle size and viscosity, an effect enhanced by increasing the total solids content. Concentrates produced from non-pasteurised milk showed the strongest shear-thinning behaviour during storage. Thus, the thermal treatment of milk before or after the concentration process, controls the structure formation of skim milk concentrates during storage.
KW - Membrane filtration
KW - Particle size
KW - Rheological behaviour
KW - Storage stability
KW - Thermal treatment
U2 - 10.1016/j.jfoodeng.2020.109922
DO - 10.1016/j.jfoodeng.2020.109922
M3 - Journal article
AN - SCOPUS:85078172706
VL - 278
JO - Journal of Food Engineering
JF - Journal of Food Engineering
SN - 0260-8774
M1 - 109922
ER -