Volatilomic Profiling for Authentication of PDO and PGI Balsamic Vinegars via HS-SPME-GC×GC-TOFMS

Balsamic vinegar (BV) is an economically and culturally significant product whose authenticity and quality are legally protected by geographical indications, such as Protected Designation of Origin (PDO) and Protected Geographical Indication (PGI). Current authentication relies largely on sensory evaluation, a practice that inherently introduces subjectivity and limits standardization. Therefore, establishing objective methodologies for product authentication remains essential. Comprehensive two-dimensional gas chromatography coupled with time-of-flight mass spectrometry (GC×GC-TOFMS) stands out as a powerful technique for volatilomic profiling, offering enhanced resolution, sensitivity, and peak capacity, thereby providing detailed chemical fingerprints that are ideal for authenticating complex matrices, such as BV.^1,2 In this study, an analytical workflow combining headspace solid-phase microextraction (HS-SPME), GC×GC-TOFMS, and multivariate statistical analysis was developed for profiling volatile compounds in seven BV samples, including five PGI- and two PDO-certified vinegars. The samples were selected to represent distinct geographical origins and production specifications. Extraction parameters were optimized by assessing the responses of compound classes, including acids, esters, furans, terpenes, and lactones. The optimized HS-SPME conditions allowed the identification of 710 volatile features. Peaks from chromatographic runs were aligned to correct retention time shifts, ensuring the consistency of data for subsequent multivariate analyses. Principal Component Analysis (PCA) demonstrated clear separation between PDO and PGI vinegars, influenced by aroma-active compounds such as (E)-whiskey lactone, α-furanone, and γ-pentalactone. This analytical approach effectively discriminates BV based on geographical origin and production practices, offering an alternative to sensory-based authentication. Future research will involve extending the methodology to assess the impact of aging and bottling practices on volatile profiles.

References:

1. Franchina, F. A., Zanella, D., Dubois, L. M. & Focant, J. F. Journal of Separation Science vol. 44 188–210.
2. Zanella, D., Focant, J. F. & Franchina, F. A. Analytical Science Advances vol. 2 213–224.