Cand. Techn. Al. Sisse Jongberg : 3. februar 2012 - 3. februar 2012
(Lecture Hall A2-70.04 (3-14), Thorvaldsensvej 40, 1870 Frederiksberg C)
Ph.D. Defendant:
Cand. Techn. Al. Sisse Jongberg
Time and Place:
Friday 3 February 2012 at 13:00 in Lecture Hall A2-70.04 (3-14), Thorvaldsensvej 40, 1870 Frederiksberg C
Summary:
Protein oxidation leads to reduced tenderness of meat, and the use of phenolic-rich plant extracts as antioxidants against the protein modifications leading to the quality loss were investigated. Accelerated protein thiol loss was observed in the beef added a phenolic antioxidant, while protein disulfide cross-link formation was found unaffected indicating that the loss of protein thiol groups were caused by other interactions than myofibrillar protein cross-linking. Further investigations found that myofibrillar proteins were modified through formation of covalent bonds between the thiol groups and the phenolic antioxidant resulting in a thiol-quinone adduct. In addition, the overall protein radical concentration was found significantly reduced in the myofibrillar protein fraction extracted from beef added phenolic antioxidant, indicating that myofibrillar proteins are protected from oxidation by phenolic antioxidants in other residues than the protein thiol groups.
Principal Supervisor:
Professor Leif H. Skibsted, Department of Food Science, Faculty of Life Sciences, University of Copenhagen
Project Supervisor:
Professor Leif H. Skibsted, Department of Food Science, Faculty of Life Sciences, University of Copenhagen
Co-Supervisor:
Consultant Mari Ann Tørngren, Danish Meat Research Institute, Teknologisk Institut, Roskilde
Scientist Lars Månsson, Danisco A/S
Associate Professor Marianne Lund Lametsch, Department of Food Sciences, Faculty of Life Science, University of Copenhagen
Assessment Committee:
Associate Professor Nanna Viereck, Department of Food Science, Faculty of Life Sciences, University of Copenhagen (chairman)
Professor Michael Davies, The Heart Research Institute, Australia
Senior Director Jacob Holm Nielsen, Arlafoods Amba, Denmark