Depth profiling of a heterogeneous food-packaging model using step-scan Fourier transform infrared photoacoustic spectroscopy

摘要

Fourier transform infrared (FTIR) spectroscopy with a photoacoustic (PA) detector was used to study a multi-layer starch- protein-polyethylene composite system. Non-destructive depth profiling was performed to identify the spectral peaks corresponding to the absorbing chemical groups of the individual components that reside in the respective layers. Well-separated peaks corre- sponding to starch, protein, and polyethylene were obtained from the FTIR-PA spectra. The analysis was confirmed by comparing the peaks from the composite layers with the peaks of the individual components.