Challenges and innovations in zeranol detection in animal products: What role for the colorimetry-based sensors? A review

Zeranol is a non-steroidal anabolic agent with estrogenic activity. It is used in the beef industry in several countries to enhance feed efficiency and promote growth. However, due to concerns about its endocrine-disrupting effects on consumers, zeranol has been banned in Europe. In countries where its use is permitted, stringent regulations have been implemented to control residue levels in animal products. Despite significant advancements in detection techniques, the most recent comprehensive review of these methods was published 17 years ago, highlighting the need for updated insights in this area. This review article provides an up-to-date overview of the methods used to determine zeranol and its metabolites in various matrices. Some conventional chromatography-based methods are discussed. Furthermore, innovative methods such as enzyme-linked immunosorbent assay, fluorescence, and colorimetry are examined. Despite the high costs of analytical instruments and the requirement for skilled personnel, this review found that they are still favored over newer techniques. Among the emerging techniques, there is a notable scarcity of reports on colorimetry-based sensors for detecting zeranol. Accordingly, the application of this method for zeranol detection in animal products is poorly understood and in need of further exploration to bridge the knowledge gap.