2.2. Preparation of the stock solutions
The polysaccharide stock solution (3% w/v) was prepared by
dissolving j-carrageenan in deionized water, followed by heat
treatment at 90 C for 60 min with magnetic stirring and subsequent
cooling to 50 C. Sodium caseinate (Na-CN) stock solution
(6% w/v) was prepared by dispersing casein in deionized water
using a magnetic stirrer, and maintaining the pH constantly adjusted
to 7.0 with 10 mol/L NaOH. After this, the protein solution
was heated to 50 C and the two stock solutions were diluted
and mixed to prepare the microgels. The temperature of the solutions
was maintained at 50 C using a thermostatic bath filled with
distilled water. Pure microgels were obtained from the j-carrageenan
solution, whilst the mixed microgels were produced from
the mixture of the j-carrageenan and sodium caseinate solutions.