BACKGROUND: Ultrafiltration (UF) has led to the recovery of valuable products from seafood processing wastes. However, the use of crustacean process wastewaters as a source of bioactive compounds with application in the chemical, pharmaceutical and food industries has been scarcely studied to date. RESULTS: This study reports the recovery of high concentrations of astaxanthin (10(-13) mu g mL(-1)) by 300 kDa ultrafiltration of shrimp cooking wastewater, indicating that astaxanthin is associated with high MW retained proteins. Individual UF with 300, 100 and 30 kDa MWCO membranes and the sequential UF 100 -> 30 kDa were the most effective configurations for protein concentration. Hydrolysates from these three protein-concentrated fractions showed very potent ACE-inhibitory (1.98, 9.87 and 23.10 mu g mL(-1) IC50 values) and beta-carotene bleaching activities compared with hydrolysates from other fish and seafood species. CONCLUSIONS: According to these results, shrimp cooking wastewater is a good source of astaxanthin and bioactive peptides. This approach based on the ultrafiltration of shrimp cooking wastewaters contributes towards the depuration of this by-product, while enabling the recovery and production of high value-added products. (C) 2015 Society of Chemical Industry