The Effect of Ultrasound Treatment in Winemaking on the Volatile Compounds of Aglianico, Nero di Troia, and Primitivo Red Wines.

Abstract

An ultrasound (US) treatment was applied during the vinification of three different red grape cultivars with the aim of assessing the impact on the volatile profile of the wines. A robust solid phase micro extraction coupled with gas chromatography mass-spectrometry (SPME-GC-MS) method was developed in order to fix the best parameters for optimizing the volatile organic compound (VOC) recovery. A 15% NaCl solution was added to the samples to increase the salting-out effect, the time/temperature were appropriately selected, and the matrix effect was evaluated by comparing synthetic and real matrices. In addition, external calibration curves were used to quantify the single volatile compounds. The analyses of the wine samples at 7 and 14 months of aging revealed that US exerted the highest effect on Aglianico, which had the highest amount of total VOC. US Nero di Troia showed similar results after 14 months of aging, while Primitivo was not affected by the treatment. Nevertheless, from discriminant analysis, a clear separation was observed between the control and ultrasound-treated wines for all three cultivars, with ethyl decanoate, ethyl isopentyl succinate, and butyric acid having the highest discriminant coefficients. In conclusion, the obtained results indicated that the effect of US treatment on the VOC profile of the wine considered in the experimentation is cultivar-dependent.