Fuente: Food Bioactives A thorough manual for using surface plasmon resonance (SPR) in real-time investigations of biomolecular interactions pertinent to food systems is provided in this protocol chapter. By tracking variations in the refractive index close to a sensor surface, SPR is a label-free optical method that can identify molecular binding events with high sensitivity. The method has been used more and more in food science research because it is especially well-suited for measuring kinetic and affinity parameters (ka, kd, and KD) in close to physiological settings. Sample preparation, ligand immobilization, interaction analysis, surface regeneration, and quality control of data acquisition are all crucial steps in SPR experimentation that are covered by the methods presented here. Practical factors such as buffer optimization, ligand purity evaluation, chip selection tactics, analyte solubilization procedures, and regeneration scouting are covered in detail in each section. Additionally, advice is given on how to reduce nonspecific interactions, adjust for refractive index discrepancies, and guarantee sensor surface stability throughout several assay cycles. In addition to detailed technical instructions, this chapter contains application-specific subsections that show how SPR can be used to characterize emulsifier-polysaccharide binding, assess the release behavior of encapsulated nutraceuticals, detect allergens and pathogens, and study enzyme-substrate kinetics in dairy systems. Along with outlining the integration of SPR with complementary tools like mass spectrometry and HPLC, the protocol also highlights experimental designs for fingerprinting and traceability in food authentication. All things considered, this chapter is a fundamental tool for scientists and business experts who want to plan, carry out, and analyze SPR tests with accuracy and consistency. The techniques described emphasise reproducibility, analytical accuracy, and real-world application in the framework of contemporary food science, supporting both fundamental and applied research, including complex food matrices, biopolymers, and bioactive compounds.