In this paper real-time, label free sensing principle based on Surface Plasmon Resonance (SPR) and gravimetric, i.e. Quartz Crystal Microbalance (QCM) are described and some applications to food analysis problems are reported. Affinity receptors are introduced and examples using antibodies, nucleic acid probes and biomimetic receptors i.e. molecular imprinted polymers (MIP) reported. In particualr pesticide, endotoxins, pathogens, Genetically Modified Organism (GMOs) detection and food origin analysis are reviewed.