It appears from these results that, in comparison with the other protectants, WPI offered the highest level of protection to L. plantarum, and the protection was concentration and strain dependent.
For B21 at a concentration of 10% w/w, 50% less WPI was required to provide similarly high survival (90%) as A17 at 20% w/w concentration.
It is important to note that native WPI at 30% w/w was still readily soluble in water at room temperature even though
it has a very high protein content of 90.4% (see Section 2.1).
We also found that concentration affects the particle size (Fig. 1a–c) and thickness of the capsule wall (Fig. 1d–e).
This aspect is discussed in Section 3.5.