The application of integrated interferometric chips for the label-free determination of three different classes of analytes in different food commodities will be presented. The particular applications are the determination of allergens (bovine milk, soy protein, and peanut protein) in goat milk or rinse water samples, of mycotoxins (fuminisin B1, aflatoxin B1, ochratoxin A, and deoxynivalenol) in beers, and pesticides (thiabendazole, imazalil, and chrorpyrifos) in grapes and wines. Detection is based on competitive immunoassays through functionalization of the sensing arms of the integrated Mach-Zehnder interferometers with the analytes or analyte-protein conjugates. The analytical sensitivities achieved allowed detection of all analytes to levels lower than those set as allowable by the EU legislations.