<p>Polyphenols play a key role in the agrifood sector, particularly in winemaking and olive oil production, where they contribute to product quality assessment. In this study, the potential interference of glucose on our previously developed Gelatin type A-based polyphenol biosensor was evaluated using Quartz Crystal Microbalance with Dissipation Monitoring (QCM-D). Since glucose is naturally present in grapes, olives, and their derivatives, its effect on the biosensor performance must be assessed to ensure reliable polyphenol detection. The biosensor response to glucose was tested across a wide concentration range (10^–6 to 3 × 10² g L⁻¹), covering typical glucose content found in musts and wines. The results showed minimal biosensor response, even at the highest glucose concentration, indicating negligible interference with the biosensor signal. These findings suggest that this biosensor can accurately detect polyphenols in real samples without significant signal distortion from glucose. Overall, the study reinforces the biosensor’s potential application in oenology and other agrifood contexts such as olive oil production.</p>