Controlling harmful contaminants and spotting fraud in the food business is crucial for preserving consumer health and safety. Detecting and screening for toxins and pollutants in food, antibiotics, and pathogens in the food processing business using traditional methods will be very expensive and time-consuming. As a result, the use of immunological techniques like ELISA, which are quick, inexpensive, accurate, and do not require sophisticated equipment, was introduced to improve food quality and safety. Indirect ELISA and sandwich ELISA are two in vitro methods for food confirmation that allow for the simultaneous analysis of numerous samples. Generally used as a diagnostic tool in pathology and medicine and for quality control testing in many industries, particularly the food industry, this immunology technique finds antibodies or antigens in food samples, pesticide residues, pathogenic microorganisms, and eventually natural materials. The use of commercial ELISA kits for identifying food ingredients and their changes throughout function and processing for safety evaluation has been debated as the technology for screening and detection has advanced in recent years. The significance of the ELISA technology and its use in identifying genetically modified foods, allergies, and eventually food fraud were also discussed in this chapter.