Oxidation stability of flavored spirits using PEG as carrier material

Význam tématu

Measuring the oxidation stability of flavored spirits is critical for ensuring product quality, shelf life and consumer safety. Oxidative degradation can lead to off-flavors, discoloration and loss of aroma, particularly in spirits infused with natural flavorings and antioxidants. Reliable, fast and reproducible methods support quality control in distilleries and help manufacturers optimize formulations and storage conditions.

Cíle a přehled studie

This study evaluates the feasibility of using the Rancimat method with polyethylene glycol (PEG) as carrier material for direct determination of oxidation stability in both flavored and unflavored gins. The objectives were to demonstrate a sample-preparation-free protocol, assess reproducibility across multiple replicates and establish induction times as a metric for oxidative resistance.

Použitá metodika

The Rancimat method accelerates oxidation by exposing a mixture of gin and PEG to a controlled airflow at elevated temperature (100–180 °C). Volatile secondary oxidation products are swept into a water-filled measuring vessel where conductivity is continuously monitored. The point of rapid conductivity increase defines the induction time, directly reflecting the sample’s oxidation stability.

Použitá instrumentace

• 892 Professional Rancimat system with eight measuring positions in two independent heating blocks.
• Polyethylene glycol (PEG) as carrier medium to facilitate volatile product transfer.
• StabNet software for instrument control, data acquisition and evaluation.

Hlavní výsledky a diskuse

Oxidation stability results for flavored gins ranged from 2.89 h to 5.60 h (relative standard deviation 3.3–7.0 %), indicating sufficient reproducibility. Unflavored gin showed a markedly shorter induction time of approximately 0.52 h (RSD 1.1–1.5 %), reflecting lower inherent antioxidant content. These findings confirm that flavor additives and naturally occurring antioxidants significantly extend oxidative resistance.

Přínosy a praktické využití metody

Direct analysis without sample preparation reduces handling errors and speeds throughput. The ability to run eight samples simultaneously enhances laboratory efficiency. Induction time data enable product benchmarking, formula optimization and shelf-life prediction, supporting quality assurance in spirit production.

Budoucí trendy a možnosti využití

Future developments may include application to a wider range of spirit categories and complex matrices, integration of real-time data analytics for predictive shelf-life modeling and coupling with compound-specific detection techniques to identify key antioxidants. Automation and miniaturization of the Rancimat setup could further streamline routine quality checks.

Závěr

The Rancimat method with PEG carrier provides a robust, reproducible and high-throughput approach for assessing oxidation stability in flavored and unflavored spirits. Its simplicity and direct-injection capability make it a valuable tool for routine quality control and product development in the beverage industry.