Nutraceutical and functional food bioactive peptides in beef

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dc.contributor.advisor Fitzgerald, Gerald F. en Ryan, Joseph Thomas 2014-02-03T17:24:34Z 2013 2013
dc.identifier.citation Ryan, J. T. 2013. Nutraceutical and functional food bioactive peptides in beef. PhD Thesis, University College Cork. en
dc.description.abstract In recent years, the potential to positively modulate human health through dietary approaches has received considerable attention. Bioactive peptides which are released during the hydrolysis or fermentation of food proteins or following digestion may exert beneficial physiological effects in vivo. The aim of this work was to isolate, characterise and evaluate Angiotensin-І-converting enzyme (ACE-І) inhibitory, antimicrobial and antioxidant peptides from the bovine myofibrillar proteins actin and myosin. In order to generate these peptides, the myofibrillar proteins actin and myosin were hydrolysed with digestive enzymes pepsin, trypsin and α-chymotrypsin, or with the industrial thermolysin-like enzyme “Thermoase”, Amano Inc. It was found that each hydrolysate generated contained peptides which possessed ACE inhibitory, antioxidant and antimicrobial activity. The peptides responsible in part for the observed ACE inhibitory, antioxidant and antimicrobial activity of a number of hydrolysates were isolated using the method of RP-HPLC and the bioactive peptides contained within each active fraction was determined using either MALDI-TOF MS/MS or N-terminal peptide sequencing. During the course of this thesis six ACE inhibitory and five antimicrobial peptides were identified. It was determined that the reported antioxidant activity was a direct result of a number of peptides working in synergy with each other. The IC50 values of the six ACE inhibitory peptides ranged in values of 6.85 to 75.7 µM which compare favourably to values previously reported for other food derived ACE inhibitory peptides, particularly the well known milk peptides IPP and VPP, IC50 values of 5 and 9 µM respectively. All five antimicrobial peptides identified in this thesis displayed activity against Escherichia coli, Salmonella typhimurium, Staphylococcus aureus and Listeria innocua with MIC values ranging from 0.625 to10 mM. The activity of each antimicrobial peptide was strain specific. Furthermore the role and importance of charged amino acids to the activity of antimicrobial peptides was also determined. Generally the removal of charged amino acids from the sequence of antimicrobial peptides resulted in a loss of antimicrobial activity. In conclusion, this thesis revealed that a range of bioactive peptides exhibiting ACE inhibitory, antioxidant and antimicrobial activities were encrypted in bovine myofibrillar proteins that could be released using digestive and industrial enzymes. Finally enzymatic hydrolysates of muscle proteins could potentially be incorporated into functional foods; however, the potential health benefits would need to be proven in human clinical studies. en
dc.format.mimetype application/pdf en
dc.language.iso en en
dc.publisher University College Cork en
dc.rights © 2013, Joseph T. Ryan. en
dc.rights.uri en
dc.subject Beef en
dc.subject Antioxidant en
dc.subject Angiotensin 1-converting enzyme en
dc.subject Bioactive peptides en
dc.subject Antimicrobial en
dc.subject.lcsh Anti-infective agents en
dc.subject.lcsh Antioxidants en
dc.title Nutraceutical and functional food bioactive peptides in beef en
dc.type Doctoral thesis en
dc.type.qualificationlevel Doctoral en
dc.type.qualificationname PhD (Science) en
dc.internal.availability Full text not available en Indefinite en 10000-01-01
dc.description.version Accepted Version
dc.contributor.funder Science Foundation Ireland en
dc.contributor.funder Department of Agriculture, Fisheries and Food, Ireland en
dc.description.status Not peer reviewed en Microbiology en Teagasc en
dc.check.type No Embargo Required
dc.check.reason This thesis is due for publication or the author is actively seeking to publish this material en
dc.check.opt-out Yes en
dc.thesis.opt-out true
dc.check.embargoformat Hard bound copy in Library only en
dc.internal.conferring Autumn Conferring 2013 en

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© 2013, Joseph T. Ryan. Except where otherwise noted, this item's license is described as © 2013, Joseph T. Ryan.
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