title: Impact of ultrafiltration and nanofiltration of an industrial fish protein hydrolysate on its bioactive properties.
abstract: BACKGROUND
  Numerous studies have demonstrated that in vitro controlled enzymatic hydrolysis of fish and shellfish proteins leads to bioactive peptides. Ultrafiltration (UF) and/or nanofiltration (NF) can be used to refine hydrolysates and also to fractionate them in order to obtain a peptide population enriched in selected sizes. This study was designed to highlight the impact of controlled UF and NF on the stability of biological activities of an industrial fish protein hydrolysate (FPH) and to understand whether fractionation could improve its content in bioactive peptides.
  
  
  RESULTS
  The starting fish protein hydrolysate exhibited a balanced amino acid composition, a reproducible molecular weight (MW) profile, and a low sodium chloride content, allowing the study of its biological activity. Successive fractionation on UF and NF membranes allowed concentration of peptides of selected sizes, without, however, carrying out sharp separations, some MW classes being found in several fractions. Peptides containing Pro, Hyp, Asp and Glu were concentrated in the UF and NF retentates compared to the unfractionated hydrolysate and UF permeate, respectively. Gastrin/cholecystokinin-like peptides were present in the starting FPH, UF and NF fractions, but fractionation did not increase their concentration. In contrast, quantification of calcitonin gene-related peptide (CGRP)-like peptides demonstrated an increase in CGRP-like activities in the UF permeate, relative to the starting FPH. The starting hydrolysate also showed a potent antioxidant and radical scavenging activity, and a moderate angiotensin-converting enzyme (ACE)-1 inhibitory activity, which were not increased by UF and NF fractionation.
  
  
  CONCLUSIONS
  Fractionation of an FPH using membrane separation, with a molecular weight cut-off adapted to the peptide composition, may provide an effective means to concentrate CGRP-like peptides and peptides enriched in selected amino acids. The peptide size distribution observed after UF and NF fractionation demonstrates that it is misleading to characterize the fractions obtained by membrane filtration according to the MW cut-off of the membrane only, as is currently done in the literature.
authors.affiliation: UMR CNRS 6250 LIENSs, Université de La Rochelle, La Rochelle, France. laurent.picot@univ-lr.fr
authors.forename: Laurent
authors.initials: L
authors.lastname: Picot
authors.forename: Rozenn
authors.initials: R
authors.lastname: Ravallec
authors.forename: Martine
authors.initials: M
authors.lastname: Fouchereau-Péron
authors.forename: Laurent
authors.initials: L
authors.lastname: Vandanjon
authors.forename: Pascal
authors.initials: P
authors.lastname: Jaouen
authors.forename: Maryse
authors.initials: M
authors.lastname: Chaplain-Derouiniot
authors.forename: Fabienne
authors.initials: F
authors.lastname: Guérard
authors.forename: Aurélie
authors.initials: A
authors.lastname: Chabeaud
authors.forename: Yves
authors.initials: Y
authors.lastname: Legal
authors.forename: Oscar Martinez
authors.initials: OM
authors.lastname: Alvarez
authors.forename: Jean-Pascal
authors.initials: JP
authors.lastname: Bergé
authors.forename: Jean-Marie
authors.initials: JM
authors.lastname: Piot
authors.forename: Irineu
authors.initials: I
authors.lastname: Batista
authors.forename: Carla
authors.initials: C
authors.lastname: Pires
authors.forename: Gudjon
authors.initials: G
authors.lastname: Thorkelsson
authors.forename: Charles
authors.initials: C
authors.lastname: Delannoy
authors.forename: Greta
authors.initials: G
authors.lastname: Jakobsen
authors.forename: Inez
authors.initials: I
authors.lastname: Johansson
authors.forename: Patrick
authors.initials: P
authors.lastname: Bourseau
mesh_terms: D000596:Amino Acids / Q000302:isolation & purification; D000818:Animals; D000975:Antioxidants / Q000302:isolation & purification / Q000494:pharmacology; D015740:Calcitonin Gene-Related Peptide / Q000302:isolation & purification; D002766:Cholecystokinin / Q000302:isolation & purification; D005396:Fish Products; D029941:Fish Proteins / Q000737:chemistry*; D005399:Fishes; D005755:Gastrins / Q000302:isolation & purification*; D006868:Hydrolysis; D008970:Molecular Weight; D010455:Peptides / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D007703:Peptidyl-Dipeptidase A / Q000302:isolation & purification / Q000494:pharmacology; D014462:Ultrafiltration / Q000379:methods
chemical_list: D000596:Amino Acids; D000975:Antioxidants; D029941:Fish Proteins; D005755:Gastrins; D010455:Peptides; D002766:Cholecystokinin; D007703:Peptidyl-Dipeptidase A; D015740:Calcitonin Gene-Related Peptide