Towards a routine application of vibrational spectroscopy to the detection of bone fragments in feedingstuffs: Use and validation of a NIR scanning microscopy method

The possibility to use NIR scanning microscopy for the detection of bone fragments in feedingstuffs has been evaluated analysing sediments derived from commercial feedingstuffs samples spiked with MBM. The method appeared sensitive enough to reveal the presence of bone fragments for MBM concentration in the feedingstuffs as low as 0.05 wt.%. The identification of MBM is done versus vegetable ingredients.The validation test, performed on a series of feedingstuffs spiked at a 0.1 wt.% MBM level (the detection limit reached by the official EU method based on optical microscopy), indicated that sensitivity (100%) and specificity (96.30%) of the investigated method are satisfactory for possible applications in screening procedure. NIR microscopy analyses turned out to be reliable and fast (including a minimal operational time for the analyst) with the additional possibility to obtain a map of the sediment, with indicated the positions of bone fragments, that then could be selectively re-analyzed by NIR spectroscopy for confirmation.