Heat-induced changes in myofibrillar protein structures and myowater of two pork qualities. A combined FT-IR spectroscopy and low-field NMR relaxometry study

J Agric Food Chem. 2006 Mar 8;54(5):1740-6. doi: 10.1021/jf0514726.

Abstract

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Body Water / chemistry*
  • Hot Temperature*
  • Magnetic Resonance Spectroscopy
  • Meat / analysis*
  • Muscle Proteins / chemistry*
  • Myofibrils / chemistry*
  • Spectroscopy, Fourier Transform Infrared
  • Swine*

Substances

  • Muscle Proteins