DETERMINATION OF THE GLOBAL SECONDARY STRUCTURE OF PROTEINS BY FOURIER-TRANSFORM INFRARED (FTIR) SPECTROSCOPY

in the development of new foods or in the control of traditional proce sses, protein functionality plays a paramount role. It has long been t heorized that changes in protein structure can alter functionality, bu t there has been a lack of reliable methodologies for observing protei n structural changes in 'real-world' food samples. Here, a technique f or determination of the global secondary structure of proteins using F ourier transform infrared (FTIR) spectroscopy in H2O instead of D2O is assessed and contrasted with other methodologies for structural deter minations. A quantitative procedure is presented for preparing and ana lysing FTIR spectra of proteins for the determination of their global secondary structural components. As an example, an analysis of the FTI R spectra of egg-white lysozyme is presented and correlated with globa l secondary structure values calculated from its X-ray crystallographi c structure. Other examples of FTIR analyses of food proteins are pres ented with consideration given to qualitative procedures for more rapi d structural analysis of processed samples.