Exploring Gelatin-A and Mouse Proline-Rich Protein 5 as Probes for Wine Polyphenol Analysis by Quartz Crystal Microbalance with Dissipation Monitoring

Polyphenols are significant compounds that impact the winemaking process, influencing key attributes such as wine quality, color, astringency, bitterness, and chemical stability. Traditionally, the wine polyphenolic content is assessed through conventional analytical methods, which are costly and time-consuming. Thus, developing novel strategies to overcome these limitations is highly desirable. Quartz Crystal Microbalance with Dissipation Monitoring (QCM-D) is an electromechanical sensor that has gained broad recognition as a fast, reliable, and label-free detection tool. The QCM-D is employed to investigate Gelatin Type A (Gel-A) and Mouse Proline-Rich Protein 5 (MP5) as probes for analyzing polyphenols in red wines. The probes have been successfully immobilized on the sensor surface, yielding molecular densities of 2.1 × 10¹⁴ and 5.1 × 10¹² molecules cm⁻² for MP5 and Gel-A, respectively. Both probes have shown promising performance in the analysis of polyphenols in wine, with both changes in the sensor's resonance frequency and dissipation with all tested samples. Notably, using MP5, a linear response of the dissipation has been observed with both the total polyphenol and hydroxybenzoic acid concentrations. These results indicate strong potential for developing a stand-alone sensor platform to directly monitor polyphenols during the winemaking process.