A novel FT-IR spectroscopic method based on lipid characteristics for qualitative and quantitative analysis of animal-derived feedstuff adulterated with ruminant ingredients

The objective of this study was to explore the ability of Fourier transform infrared (FT-IR) spectroscopy to authenticate adulterated animal-derived feedstuff. A total of 18 raw meat and bone meals (MBMs), including 9 non-ruminant MBMs and 9 ruminant MBMs, were mixed to obtain 81 binary mixtures with specific proportions (1-35%). Lipid spectral characteristics were analyzed by FT-IR spectroscopy combined with chemometrics. Changes in FT-IR spectra were observed as adulterant concentration was varied. The results illustrate ruminant adulteration can be successfully distinguished based on lipid characteristics. PLS model was established to quantify ruminant adulteration, which was shown to be valid (R-P(2) > 0.90). Furthermore, the ratios of C=C/C=O and C=C/C-H(CH2), as well as the number of C-H (-CH2) in the fatty acids of adulterated lipids, were calculated, which showed that differences in the trans fatty acid content and the degree of unsaturation were the main contributors to determination of adulteration based on FT-IR spectroscopy. (C) 2017 Published by Elsevier Ltd.