Quantum mechanically calculated NIR spectra of fatty acids

The advances in theory as well as steady development of the computing power have made quantum mechanical simulation of NIR spectra feasible. Recently, we have demonstrated the ability to accurately reproduce in theory the NIR spectra of several complex biomolecules, including fatty acids. In the present technical article, some of these achievements are overviewed. Examples of theoretical modelling of NIR spectra of short- (aliphatic chain up to four carbon atoms) and medium-chain (aliphatic chain counting six carbon atoms) fatty acids are presented and discussed. The calculated data are used directly for explaining the experimental NIR spectra of these systems. Spectral features distinctive to saturated vs. unsaturated fatty acids are essential in various types of samples typically treated by NIR spectroscopy; i.e. food, tissue, biomaterial, etc. Therefore, the theoretical study offers considerable support for basic and applied NIRS. An example of possible practical application of the results of theoretical study for biochemical studies is provided. The topic discussed here has been presented during the 18th International Conference on Near Infrared Spectroscopy (ICNIRS-2017) in Copenhagen, June 2017.