Secondary structure of food proteins by Fourier transform spectroscopy in the mid-infrared region.
Fourier transform spectroscopy in the mid-infrared (400-5,000 cm(-1)) (FT-IR) is being recognized as a powerful tool for analyzing chemical composition of food, with special concern to molecular architecture of food proteins. Unlike other spectroscopic techniques, it provides high-quality spectra with very small amount of protein, in various environments irrespective of the molecular mass. The fraction of peptide bonds in alpha-helical, beta-pleated sheet, turns and aperiodic conformations can be accurately estimated by analysis of the amide I band (1,600-1,700 cm(-1)) in the mid-IR region. In addition, FT-IR measurement of secondary structure highlights the mechanism of protein aggregation and stability, making this technique of strategic importance in the food proteomic field. Examples of applications of FT-IR spectroscopy in the study of structural features of food proteins critical of nutritional and technological performance are discussed.
Istituto Nazionale di Ricerca per gli Alimenti e la Nutrizione, Via Ardeatina, 546, 00178 Rome, Italy. carbonaro@inran.it
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D000818:Animals; D004044:Dietary Proteins; D005524:Food Technology; D006801:Humans; D011487:Protein Conformation; D011489:Protein Denaturation; D055550:Protein Stability; D017433:Protein Structure, Secondary; D011506:Proteins / Q000737:chemistry*; D040901:Proteomics / Q000379:methods; D017550:Spectroscopy, Fourier Transform Infrared / Q000295:instrumentation / Q000379:methods*
D004044:Dietary Proteins; D011506:Proteins