The protein content of particles made with higher calcium concentrations
were all estimated using Eq. (1), from the weight fraction
of the pellet. These particles were not spherical in nature,
leading to an overestimation of the volume fraction and an underestimation
of the protein content. For higher calcium concentration
(>15 mM), the protein content was between 21% and 27%.
These concentrations are well in agreement with the lower extent of swelling noted in Table 1. Particles with lower calcium concentrations
swelled and thereby decreased their protein content,
whereas particles with higher calcium concentration retained
approximately their initial size and protein content.