A decision support alternative method through NIR spectroscopy and MCC-PCA in the evaluation of Salmonella spp. in...

Bovine meat and bone meal (BMBM) is the main slaughtering by-product in slaughterhouses, and it is reused to manufacture feed food for pets. However, food safety and the harmlessness of pathogenic microorganisms, such as Salmonella spp., must be guaranteed. Considering that the BMBM industries already normally employ near-infrared spectroscopy (NIR) for quality control of other parameters, the evaluation of Salmonella spp. could be incorporated into the laboratory routines by NIR. Thus, the objective of this work was the development of a decision support method guided by NIR spectroscopy and multivariate control charts based on principal component analysis (MCC-PCA) in the evaluation of Salmonella spp. in BMBM. Samples of BMBM without Salmonella spp. (300 samples) were used in the training step and control chart establishment. Furthermore, 55 samples without Salmonella spp. were considered in an external validation step, while the control chart predicted 413 samples with Salmonella spp. The results showed that the multivariate control charts based on the PCA efficiently distinguished bovine meat and bone meal samples absent or present for Salmonella spp. Thus, NIR spectroscopy coupled with the MCC-PCA can be an alternative and a decision support method that can serve as an initial screening tool and reduce the number of analyses through the conventional method in Salmonella spp. evaluation. Moreover, it is important to highlight that we don't want people to think that NIR detects the bacteria, but rather the changes due to the presence of the bacteria.