Changes in the Aroma of a Strawberry Drink during Storage

The flavor of a commercially available strawberry drink was investigated with special regard to the changes of the sensory properties during the shelf life of the product. The experiments were performed using gas chromatographic methods after liquid−liquid extraction and after solid-phase microextraction of the headspace. A trained sensory test panel was used to substantiate the results from instrumental analyses. The relative concentrations of several compounds were followed over a storage period of six weeks at elevated temperature (37 °C), which corresponds to about 12 months storage at room temperature. Significant concentration changes of several flavor compounds were determined after a short storage time. These results correlate highly with changes in the aroma observed by the sensory test panel. Further on, changes in the sensorial relevance of aroma active compounds were monitored by comparative aroma extract dilution analysis of extracts of the fresh product and the product at the end of the declared shelf-life time. The results showed a significant decrease in flavor dilution factors of compounds with characteristic fruity attributes. Keywords: Strawberry drink; shelf life; aroma; GC−MS; SPME; sensory evaluation