Abstract:

In this research, the kinetic mechanism of sucrose release from whey protein isolate gels was studied. For
this purpose, sucrose as a food flavor component was encapsulated in whey protein gels to investigate the effects of pH,
temperature, drug loading, and ion concentration on the kinetics of sucrose release. The results showed that the releasing
process of sucrose from whey protein isolate gels could be described by the Korsmeyer-Peppas model, with a fitting
correlation coefficient R2 between 0.95–0.99. The diffusion constant n was less than 0.45, which is consistent with the
Fick diffusion mechanism. With the increase of pH, temperature or ion concentration in the range of 0.05–0.10 mol/L, the
kinetic constant K (i.e., release rate) increased, while it decreased with the increase of drug loading. Whey protein isolate
gel exhibited environmental responses, and the release of entrapped sucrose from it could be influenced by pH, temperature,
drug loading, ion concentration and other factors. Therefore, the purpose of controlling the release of entrapped contents
from the carrier could be achieved by adjusting pH, temperature, drug concentration and ion concentration.

Key words: whey protein isolate, gel, release characteristics, kinetics