Abnormal spectrum screening is a technique employing infrared analysis technology to rapidly identify milk samples that are abnormal and are therefore relevant for further investigation.

Samples can be abnormal due to different causes. Potential adulterants might be starch, whey, water, soap, plant oil or hydrolyzed protein; substances which are added to preserve milk or to increase quantity, or accidental cleaning agents or other fluid in the line that are not normally screened. These substances are added in concentrations which are similar to milk, e.g. matching the protein content of normal milk. These substances can also be mixed to produce artificial milk with the exact same apparent protein, fat and lactose concentrations. Generally, detection of fraud and adulteration of milk is time-, cost- and labor intensive.