Qualitative Evaluation of Aroma-Active Compounds in Grape and Grape-Derived Products by Means of Headspace SPME-GC/MS Analysis

Significance of the Topic

Aroma-active compounds in grapes and grape-derived products are critical determinants of flavor quality, consumer acceptance and product identity.
The complexity of volatile profiles influences wine, juice and vinegar sensorial attributes and can guide breeding, processing and quality control in the food and beverage industry.

Objectives and Study Overview

This study aimed to qualitatively profile the volatile aroma compounds in red grape berries, unfermented grape juice, wine and balsamic vinegar using headspace solid‐phase micro‐extraction (HS‐SPME) coupled with gas chromatography/mass spectrometry (GC/MS).
Comparative analysis across sample types and grape varieties evaluated the distribution of key odorants and their contribution to product character.

Methodology

A solvent-free HS‐SPME approach was optimized for fiber coating selection, extraction temperature and time, salt addition and injection parameters to maximize recovery of alcohols, esters, terpenes, carbonyls and norisoprenoids.
Key steps included:

• Equilibration at 40 °C for 20 min with 1.2 g NaCl per vial to enhance volatility.
• Extraction at 40 °C for 20 min using a triphasic PDMS-DVB-Carboxen fiber.
• Splitless injection for 2 min at 250 °C to improve peak shape and sensitivity.

Used Instrumentation

• Gas Chromatograph: PerkinElmer Clarus 680 GC/MS.
• Injector: Programmable split/splitless PSS injector with quartz liner (1 mm ID).
• Detector: Clarus MS (scan 28–250 amu).
• Autosampler: CTC CombiPAL XT with automated HS‐SPME module.
• Column: PerkinElmer Elite-VMS, 60 m x 0.32 mm x 1.8 µm.

Key Results and Discussion

Grape berries yielded 22 identifiable volatiles dominated by C6 alcohols and aldehydes, imparting green, herbaceous notes.
Grape juice exhibited the most complex profile with over 40 compounds, including terpenoids and C13 norisoprenoids responsible for floral aromas.
Wine samples showed 37 significant peaks, with ethanol dominating and esters/terpenes providing fruity and floral nuances.
Balsamic vinegar presented 32 volatiles, mainly short-chain acids and esters.
Comparative analysis of Tuscan red juices from Sangiovese and Aleatico varieties revealed markedly different terpenoid patterns, reflecting varietal aroma potential.

Benefits and Practical Applications

The HS‐SPME/GC/MS protocol offers rapid, solvent-free sample preparation, high reproducibility and broad analyte coverage.
Applications include product differentiation, quality assurance, process optimization, authenticity verification and detection of adulteration in the food and beverage sector.

Future Trends and Opportunities

• Integration with enantioselective columns and tandem MS for improved isomer discrimination.
• Automation and high-throughput platforms for large‐scale screening.
• Coupling with chemometric and data-mining tools for aroma fingerprinting and origin tracing.
• Extension to other fruits and complex matrices to broaden food authenticity and quality control capabilities.

Conclusion

The optimized HS-SPME/GC/MS method enables comprehensive qualitative profiling of grape and grape-derived product aromas with minimal sample preparation.
The approach effectively differentiates product types and grape varieties, supporting flavor optimization and rigorous quality control in the food industry.

References