Fig. 5.

Components of the ATR-FTIR spectrum characteristic for amide bands and components of lipids: acyl chain, interfacial region and headgroup (a) and method of calculating saturated to unsaturated fatty acid ratio (SFA/USA) (b). Second derivative deconvolution of the Amide I band frequencies and assignments to secondary structure for proteins present in the measured samples (c). The assignment of wavenumber to particular secondary structure of protein was made on the basis of literature [8,9,29].