Microparticulated whey protein (MWP) concentrate was kindly
supplied by Arla Foods Ingredients (Viby J, Denmark) and used without
further treatment. All chemicals used, including hydrochloric acid, sodium
hydroxide, sodium phosphate monobasic, sodium phosphate dibasic,
and Fluorescein isothiocynate (FITC) isomer I, were purchased
from Sigma-Aldrich