Random forest and infrared spectroscopy to detect contamination of freeze-dried milk by ivermectin residues

Abstract

Veterinary drugs in milk poses a risk to consumers’ health. Little attention is paid to investigating residues of veterinary medicines in powdered milk, then there is a need to develop new methods for monitoring these residues. We proposed the use of random forest (RF) for the prediction of the concentration of ivermectin residues in freeze-dried milk, using FTIR spectroscopy. Eight hundred models were tested and after fine tuning the best RF model was obtained with 800 trees, 5 variables for each tree, node size 1, and 75% of the data for training. The RF regression model demonstrated good ability to predict the concentration of ivermectin residues in freeze-dried milk, with correlation and determination coefficients greater than 0.96 and low error and residual values (approximately 1.0). The proposed method is fast, simple, sensitive, low cost, non-destructive and environmentally friendly, being an alternative to make the control of ivermectin residues in milk.