title: Incorporation of liposomes containing squid tunic ACE-inhibitory peptides into fish gelatin.
abstract: BACKGROUND
  Hydrolysates from collagen of jumbo squid (Dosidicus gigas) tunics have shown excellent angiotensin I-converting enzyme (ACE)-inhibitory activity. However, peptides directly included in food systems may suffer a decrease in activity, which could be minimized by loading them into nanoliposomes.
  
  
  RESULTS
  A fraction of peptides with molecular weights <1 kDa obtained from hydrolyzed squid tunics, with reasonably high ACE-inhibitory activity (half-maximal inhibitory concentration IC50 = 0.096 g L(-1)), was encapsulated in phosphatidylcholine nanoliposomes. The peptide concentration affected the encapsulation efficiency and the stability of the resulting liposomes, which remained with a high zeta potential value (-54.3 mV) for at least 1 week at the most suitable peptide concentration. The optimal peptide concentration was established as 1.75 g L(-1). Liposomes obtained with this peptide concentration showed an encapsulation efficiency of 53%, a zeta potential of -59 mV, an average diameter of 70.3 nm and proved to be stable in the pH range 3-7 at 4 °C.
  
  
  CONCLUSIONS
  Liposomes containing ACE-inhibitory peptides were incorporated in fish gelatin without detriment to the rheological properties and thermal stability of the resulting cold-induced gel. The ACE-inhibitory activity of the peptide fraction, which was not affected by the encapsulation process, conferred the bioactive potential to the nanoliposome-containing gelatin gel.
authors.affiliation: Instituto de Ciencia y Tecnología de Alimentos y Nutrición (ICTAN, CSIC), C/ José Antonio Novais, 10, E-28040, Madrid, Spain.
authors.forename: Mauricio
authors.initials: M
authors.lastname: Mosquera
authors.affiliation: Instituto de Ciencia y Tecnología de Alimentos y Nutrición (ICTAN, CSIC), C/ José Antonio Novais, 10, E-28040, Madrid, Spain.
authors.forename: Begoña
authors.initials: B
authors.lastname: Giménez
authors.affiliation: Instituto de Ciencia y Tecnología de Alimentos y Nutrición (ICTAN, CSIC), C/ José Antonio Novais, 10, E-28040, Madrid, Spain.
authors.forename: Pilar
authors.initials: P
authors.lastname: Montero
authors.affiliation: Instituto de Ciencia y Tecnología de Alimentos y Nutrición (ICTAN, CSIC), C/ José Antonio Novais, 10, E-28040, Madrid, Spain.
authors.forename: Maria Carmen
authors.initials: MC
authors.lastname: Gómez-Guillén
mesh_terms: D000806:Angiotensin-Converting Enzyme Inhibitors / Q000737:chemistry / Q000494:pharmacology; D000818:Animals; D003094:Collagen / Q000737:chemistry; D049832:Decapodiformes / Q000737:chemistry*; D004355:Drug Stability; D005399:Fishes; D005780:Gelatin / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D008081:Liposomes / Q000008:administration & dosage / Q000737:chemistry*; D008970:Molecular Weight; D053758:Nanoparticles; D010316:Particle Size; D010455:Peptides / Q000008:administration & dosage; D010713:Phosphatidylcholines; D012212:Rheology
chemical_list: D000806:Angiotensin-Converting Enzyme Inhibitors; D008081:Liposomes; D010455:Peptides; D010713:Phosphatidylcholines; D005780:Gelatin; D003094:Collagen
keywords: ACE-inhibitory activity; fish gelatin; nanoliposomes; peptides; squid collagen