Detection of adulteration in cooked meat products by mid-infrared spectroscopy.

Mid-infrared spectroscopy was used to discriminate between pure beef and beef containing 20% w/w of a range of potential adulterants (heart, tripe, kidney, and liver). Spectra were acquired from raw samples and from samples cooked using two different cooking regimes. Chemometric methods (principal component analysis, partial least squares regression, and linear discriminant analysis) applied to the spectra showed that discrimination between the pure and adulterated sample types was possible, irrespective of cooking regime. The cross-validated classification success rate obtained was approximately 97%. Discrimination between all five sample types (pure beef and beef containing one of each of the four adulterants) at each level of cook was also possible, but became more difficult as the cooking level increased.