Analysis of potato chips using FTIR photoacoustic spectroscopy

The suitability of Fourier transform infrared photoacoustic spectroscopy (F TIR-PAS) for analysing potato chips was investigated. The functional groups , vibration modes and intensities corresponding to frequencies related to m oisture, fat and protein in PA spectra were labelled. Oxidation experiments were carried out by heating home-made chips in a convection oven at 80 deg rees C. Changes in chemical groups related to fat and oh were observed visu ally and statistically. Spectral data were analysed using PCA correlation a nd a linear discriminant analysis technique with squared Mahalanobis distan ce metric to estimate the extent of oxidation. Results showed that deterior ation indeed could be monitored by photoacoustic spectroscopy. Depth profil e analysis of the samples showed that a spectral difference in the fat, moi sture and protein bands at different layers exists. Results demonstrated th at FTIR-PAS with its depth-profiling capability could be used for qualitati ve analysis. (C) 2000 Society of Chemical Industry.