title: Characterization, antioxidative and ACE inhibitory properties of hydrolysates obtained from thornback ray (Raja clavata) muscle.
abstract: Thornback ray muscle hydrolysates (TRMHs) prepared by treatment with proteases from Bacillus subtilis A26 (TRMH-A26), Raja clavata crude alkaline protease extract (TRMH-Crude), Alcalase (TRMH-Alcalase) and Neutrase (TRMH-Neutrase) were elaborated and their antioxidant properties and angiotensin I-converting enzyme (ACE) inhibitory activities were tested. TRMHs showed different degrees of hydrolysis (DH from 11 to 22%) and hydrophobic/hydrophilic peptide ratio. Protein content varied from 71 to 74%. Gly, Pro, Asp and Asn were the most prominent amino acids, while hypoxanthine was the major nucleotide related compound present. The antioxidant activity was assayed using various tests. TRMH-Neutrase exhibited the highest antioxidant activity in DPPH scavenging, reducing power and inhibition of β-carotene bleaching tests. However in the total antioxidative efficacy, TRMH-Crude exhibited the highest activity. TRMH-Crude and TRMH-Neutrase were the most potent to prevent DNA oxidation by Fenton reagent. Concerning anti-ACE activity, TRMH-A26 and TRMH-Neutrase exhibited the highest activity with 87% at 5mg/ml. The results revealed that TRMHs could be employed as a protein source in food additive processing or diets for aquatic organisms and other farmed animals.
  
  
  CONCLUSIONS
  The present study explores for the first time the elaboration of enzymatic hydrolysates from thornback ray R. clavata. The hydrolysates are well characterized and showed an interesting protein content as well as the presence of nucleotide related compounds, essential amino acids and taurine, which make them an interesting source of fish meal in aquaculture feeds. The hydrolysates were found to exhibit ACE inhibitory activity and antioxidant activity. The hydrolysates could serve also as a potential protein source for functional foods.
authors.affiliation: Laboratory of Enzyme Engineering and Microbiology, University of Sfax, National Engineering School of Sfax, B.P. 1173, 3038 Sfax, Tunisia. Electronic address: lassouedimen@yahoo.fr.
authors.forename: Imen
authors.initials: I
authors.lastname: Lassoued
authors.affiliation: Instituto de agroquímica y Tecnología de Alimentos (CSIC), Avd. Agustín Escandino, 7, 46980 Paterna, Valencia, Spain.
authors.forename: Leticia
authors.initials: L
authors.lastname: Mora
authors.affiliation: Laboratory of Enzyme Engineering and Microbiology, University of Sfax, National Engineering School of Sfax, B.P. 1173, 3038 Sfax, Tunisia.
authors.forename: Rim
authors.initials: R
authors.lastname: Nasri
authors.affiliation: Laboratory of Enzyme Engineering and Microbiology, University of Sfax, National Engineering School of Sfax, B.P. 1173, 3038 Sfax, Tunisia.
authors.forename: Marwa
authors.initials: M
authors.lastname: Aydi
authors.affiliation: Instituto de agroquímica y Tecnología de Alimentos (CSIC), Avd. Agustín Escandino, 7, 46980 Paterna, Valencia, Spain.
authors.forename: Fidel
authors.initials: F
authors.lastname: Toldrá
authors.affiliation: Instituto de agroquímica y Tecnología de Alimentos (CSIC), Avd. Agustín Escandino, 7, 46980 Paterna, Valencia, Spain.
authors.forename: María-Concepción
authors.initials: MC
authors.lastname: Aristoy
authors.affiliation: Laboratory of Enzyme Engineering and Microbiology, University of Sfax, National Engineering School of Sfax, B.P. 1173, 3038 Sfax, Tunisia.
authors.forename: Ahmed
authors.initials: A
authors.lastname: Barkia
authors.affiliation: Laboratory of Enzyme Engineering and Microbiology, University of Sfax, National Engineering School of Sfax, B.P. 1173, 3038 Sfax, Tunisia.
authors.forename: Moncef
authors.initials: M
authors.lastname: Nasri
mesh_terms: D000595:Amino Acid Sequence; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000138:chemical synthesis*; D000818:Animals; D000975:Antioxidants / Q000138:chemical synthesis*; D008969:Molecular Sequence Data; D009124:Muscle Proteins / Q000378:metabolism*; D010447:Peptide Hydrolases / Q000737:chemistry; D011492:Protein Hydrolysates / Q000138:chemical synthesis* / Q000378:metabolism*; D012860:Skates, Fish / Q000378:metabolism*
chemical_list: D000806:Angiotensin-Converting Enzyme Inhibitors; D000975:Antioxidants; D009124:Muscle Proteins; D011492:Protein Hydrolysates; D010447:Peptide Hydrolases
keywords: ACE inhibitory activity; Antioxidative activity; Enzymatic hydrolysis; Thornback ray (Raja clavata) muscle