For continuous preparation of bioactive peptide-containing fractions, a CSTR was set up with pepsin immobilized on a new support: acidic alumina treated with 2-ethanolamine-O-phosphate (2-EAOP). Hydrolyses were performed at pH 3; 23 C. Kinetic studies were focused on the appearance of two opioid peptides (LVV-haemorphin-7, VV-haemorphin-7), an analgesic peptide (neokyotorphin) and an antibacterial peptide (alpha 1-23 peptide). The optimal concentration of LVVh-7 was obtained after 2 h incubation. This incubation time was chosen to be the residence time for continuous production of a hydrolysate enriched in active transient peptides. Stationary concentrations of these peptides were obtained for more than 20 h at the output of the CSTR. Respectively, 30 mg LVVh-7, 28 mg VVh-7 and 28 mg a1-23 antibacterial peptide were produced from 5 g bovine haemoglobin after 20 h of reactor working. Neokyotorphin could not be prepared by this way because of too low production. (c) 2005 Elsevier Ltd. All rights reserved.