Influence of Aging and Salting on Protein Secondary Structures and Water Distribution in Uncooked and Cooked Pork. A Combined Ft-ir Microspectroscopy and 1h Nmr Relaxometry Study.
From: Department of Food Science, Research Center Foulum, Danish Institute of Agricultural Sciences, DK-8830 Tjele, Denmark. Zhiyun.Wu@agrsci.dk
Journal of agricultural and food chemistry
- Publish Date: Nov 2006
- ISSN: 0021-8561
- Volume: 54
- Issue: 22
- Pages: 8589-97
- Medium: Print
- Language: English
- Citation (JAMA): Wu Zhiyun, Bertram Hanne Christine, Kohler Achim, et al. Influence of Aging and Salting on Protein Secondary Structures and Water Distribution in Uncooked and Cooked Pork. A Combined Ft-ir Microspectroscopy and 1h Nmr Relaxometry Study.. J. Agric. Food Chem. Nov 2006;54:8589-97
Abstract
Fourier transform infrared (FT-IR) microspectroscopy and low-field (LF) proton NMR transverse relaxation measurements were used to study the changes in protein secondary structure and water distribution as a consequence of aging (1 day and 14 days) followed by salting (3%, 6%, and 9% NaCl) and cooking (65 degrees C). An enhanced water uptake and increased proton NMR relaxation times after salting were observed in aged meat (14 days) compared with nonaged meat (1 day). FT-IR bands revealed that salting induced an increase in native beta-sheet structure while aging triggered an increase in native alpha-helical structure before cooking, which could explain the effects of aging and salting on water distribution and water uptake. Moreover, the decrease in T2 relaxation times and loss of water upon cooking were attributed to an increase in aggregated beta-sheet structures and a simultaneous decrease in native protein structures. Finally, aging increased the cooking loss and subsequently decreased the final yield, which corresponded to a further decrease in T2 relaxation times in aged meat upon cooking. However, salting weakened the effect of aging on the final yield, which is consistent with the increased T2 relaxation times upon salting for aged meat after cooking and the weaker effect of aging on protein secondary structural changes for samples treated with high salt concentration. The present study reveals that changes in water distribution during aging, salting, and cooking are not only due to the accepted causal connection, i.e., proteolytic degradation of myofibrillar structures, change in electrostatic repulsion, and dissolution and denaturation of proteins, but also dynamic changes in specific protein secondary structures.
Mesh Headings (Keywords): Animals, Cookery, Magnetic Resonance Spectroscopy, Protein Structure, Secondary, Proteins, Protons, Sodium Chloride, Spectroscopy, Fourier Transform Infrared, Swine, Time Factors, Water
Check for Full Text / PubMed Unique Identifier (PMID): 17061838
This abstract is part of PubMed, a service of the U.S. National Library of Medicine. PubMed includes more than 17 million citations from MEDLINE and other life science journals for biomedical articles. See Copyright and Disclaimers.
Linked medical terms appearing on this page are added by Healia to help readers find more information and are not part of the original PubMed document.
The data herein was last updated on July 8th, 2008 and may not reflect the most current and accurate data available from NLM.