Application of near-infrared microscopy (NIRM) for the detection of meat and bone meals in animal feeds: A tool for food and feed safety

This paper reports on the development and validation of a method for detecting meat and bone meal (MBM) in compound feeds by near-infrared reflectance microscopy (NIRM) as an alternative in food and feed safety. A FT-NIR (Fourier transformer-near-infrared reflectance) instrument attached to a microscope was used to build up a spectral library containing reference feed particles identified as plant or animal origin, from various sources. Spectra were collected directly from particles in the NIR spectrum region (1112–2500 nm). The spectral library sample set was used to develop various discriminant models to classify spectra as MBM or plant material. The best discriminant model was obtained using partial least squares (PLS) discriminant analysis and standard normal variate and detrending (SNVD) and first derivative for spectrum pretreatment; this model had a coefficient of determination of 0.95 and a standard error of cross-validation of 0.133. The model was externally validated. The results confirmed NIRM as a valuable technique for detection of banned MBM.