Absorbance measurements were conducted using an SP-300
PLUS Optima UV-VIS spectrophotometer (Tokyo, Japan) at a wavelength
of 400 nm. The samples were placed in a 1 cm path length
cuvette, and the absorbance (Abs) was measured at 22 2 C.
For time-dependent spectrophotometric measurements,
a volume of 3 ml of a sodium caseinate/A.g mixed dispersion of the
desired pH was placed in the cuvette, and the absorbance was
followed for 20 min with a measurement step of 30 s.