The digestibility in vivo of algal proteins is not well documented, and available studies about
their assimilation by humans have not provided conclusive results. However, several workers have
described a high rate of algal protein degradation in vitro by proteolytic enzymes such as pepsin,
pancreatin and pronase (Fujiwara-Arasaki 1979, Ryu et al. 1982). Comparable results are observed with
proteins from green and brown seaweeds. However, for these seaweeds, the high phenolic content might
limit protein availability in vivo and thus moderate in vitro figures. This situation is probably not found
for the green and red seaweeds, which possess low levels of phenols and a higher protein content.