Structured muscle foods

Keywords Protein structure, muscle food, thermal treatment, Raman spectroscopy, infrared spectroscopy... 

The OSI was primarily developed for oil or fat samples. It is possible to use the method on lipids extracted from foodstuffs however, such lipids may not have the same oxidative stability as the food since the physical structures are different. Additionally, muscle foods oxidize rapidly at elevated temperature due to physical and chemical alterations during cooking thus, this method probably will not be useful with raw meats. 

Polarizing microscopy is used to examine food components that exhibit birefringence (an ordered crystalline structure). Many food components are birefringent, e.g., starch, plant cell walls, specialized stone cells in some plant tissues, muscle fibers, fats from both plant and animal sources, and different types of flavor and seasoning components. 

Raman spectroscopy is a suitable and direct technique that provides information on secondary and tertiary protein structures [23-26]. It is a powerful tool for investigation of protein structure in solid and liquid food systems in general [14, 27, 28], and for determination of the protein structure in muscle foods (meat or fish) in particular [15-18]. The spectral assignments of protein Raman bands are usually based on model compoxmds such as amino acids or short peptides. 

IR spectroscopy is another vibrational spectroscopic method used to determine the conformational structure of proteins and polypeptides. NIR spectroscopy provides little interpretable protein structural information because the broad bandwidth produces a severe overlap of most of the bands in the NIR spectra. As a consequence, the use of NIR is limited to basic structure determination in food components, and it has not been used for in-depth study of protein structural changes in muscle foods. On the other hand, mid-IR spectroscopy is a powerful tool for investigating the conformation of the polypeptide backbone of proteins. For these reasons, this chapter focuses on mid-IR spectroscopy. In mid-IR spectroscopy, the frequencies of amide I and amide II bands are very sensitive to protein conformation in food [18, 33, 34] and therefore to protein structural changes produced by thermal treatment [22]. 

Vibrational Spectroscopy to Elucidate Structural Changes Induced by Thermal Treatment in Muscle Foods... 

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