title: Antioxidant, antihypertensive and antimicrobial properties of ovine milk caseinate hydrolyzed with a microbial protease.
abstract: BACKGROUND
  Bioactive peptides might be released from precursor proteins through enzymatic hydrolysis. These molecules could be potentially employed in health and food products. In this investigation, ovine milk caseinate hydrolysates obtained with a novel microbial protease derived from Bacillus sp. P7 were evaluated for antioxidant, antimicrobial, and angiotensin I-converting enzyme (ACE)-inhibitory activities.
  
  
  RESULTS
  Antioxidant activity measured by the 2,2'-azino-bis-(3-ethylbenzothiazoline)-6-sulfonic acid method increased with hydrolysis time up to 2 h, remaining stable for up to 4 h. Hydrolysates showed low 2,2-diphenyl-1-picrylhydrazyl radical-scavenging abilities, with higher activity (31%) reached after 1 h of hydrolysis. Fe(2+) -chelating ability was maximum for 0.5 h hydrolysates (83.3%), decreasing thereafter; and the higher reducing power was observed after 1 h of hydrolysis. ACE-inhibitory activity was observed to increase up to 2 h of hydrolysis (94% of inhibition), declining afterwards. 3 h hydrolysates were shown to inhibit the growth of Bacillus cereus, Corynebacterium fimi, Aspergillus fumigatus, and Penicillium expansum.
  
  
  CONCLUSIONS
  Ovine caseinate hydrolyzed with Bacillus sp. P7 protease presented antioxidant, antihypertensive, and antimicrobial activities. Hydrolysis time was observed to affect the evaluated bioactivities. Such hydrolysates might have potential applications in the food industry.
authors.affiliation: Laboratório de Bioquímica e Microbiologia Aplicada, Instituto de Ciência e Tecnologia de Alimentos, Universidade Federal do Rio Grande do Sul, 91501-970 Porto Alegre, RS, Brazil.
authors.forename: Ana Paula F
authors.initials: AP
authors.lastname: Corrêa
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Daroit
authors.forename: Julise
authors.initials: J
authors.lastname: Coelho
authors.forename: Stela M M
authors.initials: SM
authors.lastname: Meira
authors.forename: Fernanda C
authors.initials: FC
authors.lastname: Lopes
authors.forename: Jéferson
authors.initials: J
authors.lastname: Segalin
authors.forename: Patrícia H
authors.initials: PH
authors.lastname: Risso
authors.forename: Adriano
authors.initials: A
authors.lastname: Brandelli
mesh_terms: D000806:Angiotensin-Converting Enzyme Inhibitors / Q000737:chemistry / Q000494:pharmacology; D000818:Animals; D000890:Anti-Infective Agents / Q000737:chemistry / Q000494:pharmacology*; D000959:Antihypertensive Agents / Q000737:chemistry / Q000494:pharmacology*; D000975:Antioxidants / Q000737:chemistry / Q000494:pharmacology*; D001409:Bacillus cereus / Q000187:drug effects; D001426:Bacterial Proteins / Q000302:isolation & purification / Q000378:metabolism*; D002364:Caseins / Q000302:isolation & purification / Q000378:metabolism*; D003352:Corynebacterium / Q000187:drug effects; D010450:Endopeptidases / Q000302:isolation & purification / Q000378:metabolism*; D005260:Female; D006868:Hydrolysis; D007502:Iron Chelating Agents / Q000737:chemistry / Q000494:pharmacology; D007700:Kinetics; D003904:Mitosporic Fungi / Q000187:drug effects; D010084:Oxidation-Reduction; D010446:Peptide Fragments / Q000032:analysis / Q000494:pharmacology; D011492:Protein Hydrolysates / Q000737:chemistry / Q000494:pharmacology*; D034561:Sheep, Domestic; D021241:Spectrometry, Mass, Electrospray Ionization
chemical_list: D000806:Angiotensin-Converting Enzyme Inhibitors; D000890:Anti-Infective Agents; D000959:Antihypertensive Agents; D000975:Antioxidants; D001426:Bacterial Proteins; D002364:Caseins; D007502:Iron Chelating Agents; D010446:Peptide Fragments; D011492:Protein Hydrolysates; D010450:Endopeptidases