Heat-induced changes in myofibrillar protein structures and myowater of two pork qualities. A combined FT-IR spectroscopy and low-field NMR relaxometry study.
Low-field NMR T(2) and Fourier transform infrared (FT-IR) measurements were performed on meat samples of two qualities (normal and high ultimate pH) during cooking from 28 degrees C to 81 degrees C. Pronounced changes in both T(2) relaxation data and FT-IR spectroscopic data were observed during cooking, revealing severe changes in the water properties and structural organization of proteins. The FT-IR data revealed major changes in bands in the amide I region (1700-1600 cm(-)(1)), and a tentative assignment of these is discussed. Distributed NMR T(2) relaxation data and FT-IR spectra were compared by partial least-squares regression. This revealed a correlation between the FT-IR peaks reflecting beta-sheet and alpha-helix structures and the NMR relaxation populations reflecting hydration water (T(2B) approximately 0-10 ms), myofibrillar water (T(21) approximately 35-50 ms), and also expelled "bulk" water (T(2) relaxation times >1000 ms). Accordingly, the present study demonstrates that definite structural changes in proteins during cooking of meat are associated with simultaneous alterations in the chemical-physical properties of the water within the meat.
Bertram
Hanne Christine
HC
Department of Food Science, Danish Institute of Agricultural Sciences, Research Centre Foulum, P.O. Box 50, DK-8830 Tjele, Denmark. HanneC.Bertram@agrsci.dk
Kohler
Achim
A
Böcker
Ulrike
U
Ofstad
Ragni
R
Andersen
Henrik J
HJ
D000818:Animals; D001834:Body Water / Q000737:chemistry*; D006358:Hot Temperature; D009682:Magnetic Resonance Spectroscopy; D008460:Meat / Q000032:analysis*; D009124:Muscle Proteins / Q000737:chemistry*; D009210:Myofibrils / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D013552:Swine
D009124:Muscle Proteins