Preservatives play a crucial role in modern food safety by extending shelf life and inhibiting microorganisms responsible for spoilage and foodborne illnesses. With the growing demand for processed and packaged foods, reliable detection methods and strict enforcement of health legislation have become essential. At the same time, increasing consumer awareness has raised concerns over artificial additives, pushing the food industry to seek safer, natural alternatives. Food preservatives, whether natural or synthetic, are indispensable in food science and technology, ensuring safety, longevity, and quality. However, they raise concerns related to long-term health effects, regulatory limits, and hidden additives. This chapter reviews current knowledge on detection methods, emphasizing recent trends, advances, and future directions to meet the need for effective, reliable, and accessible testing. Traditional detection relies on laboratory-based techniques such as chromatography (HPLC, GC-MS) and spectroscopy (UV-VIS, NMR), which provide high sensitivity but require time and sophisticated equipment. Recently, new approaches have emerged: rapid, low-cost, and portable methods. DNA-based techniques like PCR allow highly specific detection of trace preservatives, while nanotechnology has enabled miniaturized devices for on-site analysis. Automation and high-throughput systems also improve efficiency by processing large sample volumes simultaneously. Future perspectives highlight integrating artificial intelligence and machine learning to enhance prediction, analysis, and monitoring of preservatives, ensuring greater accuracy, speed, and reliability in food safety.