Fig. 1b shows that an increase in the calcium
chloride concentration from 1.5 to 3% (w/v) at 2% (w/v) alginate
concentration had little effect on the loading efficiency (77.3 1.1%,
82.2 2.4%, respectively). Former studies showed that the diffusion
of high molecular weight substances from the Ca-alginate beads
into the bulk solution was little affected by increases in the CaCl2
concentration (1e2% w/v), but it was considerably limited by increases
in alginate concentration (2e4% w/v) (Tanaka et al., 1984).
Therefore, alginate concentration plays a key role for enzyme
entrapment into Ca-alginate beads.