Preparation of Milk and Cheese Extracts
Goat caseins (GCN) and goat whey proteins
(GW) were separated from goat’s raw milk.
Milk fat was removed after centrifugation at
5000 g for 30 min at 30°C. Milk was diluted
1:3 in water and pH was adjusted at 4.6 with
1N HCl. After 1 h at room temperature with
agitation the solution was centrifuged for
10min 8000 g. Caseins contained in the pellet
were resuspended in water at pH 7 at room
temperature. Both whey proteins contained
in the supernatant and solubilized caseins
were dialyzed against milli-Q water for 48 h
at 4°C and lyophilized. They were dissolved
in Milli-Q water just prior use at the
appropriate concentration.
Cheeses (1 g) were grated and suspended in
5 mL of 0.4 M trisodium citrate buffer pH 8.3.
The suspensions were homogenized for 1
min in an ice bath using an Ultra-Turrax T25
(IKA-Labortechnik, Staufen, Germany).