Purifying chitin and recovering other crustacean shell compounds for use is one of the challenges on which the Biotechnology and Marine Resources unit of the IFREMER has embarked. This work, carried out in close collaboration with the UMR CNRS GEPEA, was initially the subject of a doctoral thesis (Karine Le Roux) and then post-doctoral research (Marius Socol). The successful research generated led to a patent being filed and several valuations in scientific journals and at international congresses.

To meet this challenge, the unit used one of its historical skills based on the enzymatic hydrolysis processes. The enzymatic path had already been explored for the deproteinization of the cuticle. The major innovation proposed by the IFREMER and which was the subject of the patent consisted in simultaneously combining deproteinization and demineralisation by proposing an effective enzymatic hydrolysis process in an acidic medium using a “weak” acid. Various “food” acids can therefore be the candidate for demineralisation and obtain a reaction “buffer” pH in the order of 3 to 4. So, numerous industrial proteases are able to render the protein components of the matrix soluble, enriching the aqueous phase in peptides of interest at a directly operational pH. Outside the rapid inactivation phase of the enzyme by temperature, the processing remains “gentle”, making makes it possible to conserve the bioactive potential of this phase. In six hours, the chitin extracted from the shells reaches a significant purity level (over 90% for many enzymes and over 92% in the case of ASP in formic acid). This work was awarded the “Prix des Techniques Innovantes pour l’Environnement” (Prize for Innovative Environmental Technologies) in 2012.

This work constitutes one of the experimental bases for the research work on the peptide size distribution kinetics modelling during controlled enzymatic proteolysis led by the BRM unit of the IFREMER. The intensification of this type of reaction by physical processes (sonication, microwave, reactive extrusion, etc.) is also the subject of collaborative research by this unit in close connection with the GEPEA.