Rapid Detection of Hydrolyzed Leather Protein Adulteration in Infant Formula by Near-infrared Spectroscopy

Hydrolyzed leather protein (HLP), which is collagen extracted from leather scraps, was intentionally added into dairy products by some illegal dairy producers and has caused food safety scares in China. In this study, near-infrared (NIR) spectroscopy and chemometric analysis were employed to detect HLP adulteration in infant formula. Infant formula adulterated with HLP powder can be well discriminated from authentic samples by using soft independent modelling of class analogy (SIMCA) method. Furthermore, partial least squares regression (PLS) and support vector regression (SVR) models were developed, optimized and compared for quantitative analyses of ALP adulteration concentrations. The SVR modelling method has demonstrated a better predicted capacity than PLS, and a relatively high (7.42) ratio of prediction (RPD) can be achieved. NIR spectroscopy coupled with the chemometric analysis technique could be a useful tool for simple, rapid, economical and non-destructive detection of IMP adulteration in dairy products.