Food adulteration is defined as the intentional alteration of food composition for economic gain or deceptive practices. The detection of food adulterants poses a significant challenge to food safety and consumer trust. The advancement in nanomaterial-based optical probes offers promising solutions to enhance the sensitivity, and selectivity of detecting various adulterants in food products. This book chapter provides an overview of the latest developments in nanomaterial-enabled fluorescence, SPR, and SERS-based optical sensing techniques for the detection of food adulterants. Researchers have developed innovative sensing platforms capable of detecting adulterants at trace levels by leveraging the unique optical properties of nanomaterials, such as plasmonic nanoparticles, quantum dots, and carbon-based nanomaterials. This chapter discusses the principles underlying nanomaterial-based optical probes and the recent advancements in technologies to detect the adulteration to highlight the design and fabrication and their potential applications in ensuring food authenticity and its safety.