When total carotenoid contents of carotenoproteins extracted from Pacific white shrimp shells without and with the aid of crude protease at different levels were determined (Fig. 1B), similar trends were found to those of carotenoprotein recovery (Fig. 1A). No marked changes in carotenoid content were observed after 60 min of hydrolysis (p>0.05). At the same hydrolysis time, total carotenoid contents of shrimp shells hydrolysed with crude protease was higher than those without crude protease (p0.05). For carotenoproteins extracted using high protease levels (20 and 30 unit/g sample), carotenoid content decreased in both samples when hydrolysis time was more than 120 min (p