By: Gudjon Thorkelsson, Icelandic Fisheries Laboratories and Dr. Laurent Picot, University of LaRochelle
June 15. 2005
Screening of hydrolysates obtained from by-products and underutilised fish has shown several promising effects.
The main objective of project 4.1. PROPEPHEALTH is to screen, map and recover new, health beneficial compounds from seafood by-products and underutilised species by advanced mild refining processes in order to develop new bioactive, functional seafood ingredients. Some compounds could in their isolated form be used by the pharmaceutical industry. In the first part of the project, samples of dried protein hydrolysates from three SMEs, CTPP in France, Marinova in Denmark and Primex in Iceland, were screened for bioactive properties. The main results obtained until now suggest that fish hydrolysates contain molecules that could provide benefits beyond basic nutrition:
All fish hydrolysates exerted a weak to moderate in vitro inhibition of ACE (Angiotensin I-Converting Enzyme), suggesting that fish proteins hydrolysis constitute a good process for the recovery of hypotensive peptides with an activity, that could be compensated by important nutritional intake.
3 hydrolysates, issued from one fish species, were identified as good inhibitors of the in vitro proliferation of two human breast cancer lines. Fractionation of hydrolysates, purification and identification of the peptides responsible for this activity has started.
C-GRP (Calcitonin Gene Related Peptide) and CT (Calcitonin)-like activities were demonstrated in some of the fish hydrolysates, suggesting the presence of peptides that could be used to modulate calcium and phosphorus metabolism. Gastrin and CCK (Cholecystokinin)-like activities were also demonstrated. Identification of the peptides exerting these activities could be of great interest in animal feed to stimulate digestive enzyme secretion and improve intestinal mobility.
Antioxidative and free radical scavenging properties were also demonstrated in the fish protein hydrolysates. Antioxidants can safely interact with free radicals and terminate the chain reaction before vital molecules are damaged. Free radicals have been related with aging, diseases such as cancer, diabetes and neurological disorders.
The in vitro screening is the first step in the exciting journey of developing new bioactive, functional seafood ingredients with beneficial physical and sensory properties. The next steps will be to recover, identify and then test the active fractions or components in in vivo trials.
