HOW DOES ULTRASOUND TREATMENT AFFECT THE AGEING PROFILE OF AN ITALIAN RED WINE?

Abstract

Many wine styles require moderate or extended ageing to ensure optimal consumer experience. However, few consumers have the interest or ability to age wine themselves, and holding wine in optimal conditions for extended periods is expensive for producers. A study was conducted on the use of ultrasound energy on wine, with particular reference to its impact on sensory and chemical profiles. The OIV has authorised the use of ultrasound for processing crushed grapes (must) in Resolution OENO 616-2019, but not yet for finished wine1,2. Nonetheless, the method is considered to have potential for optimising wine ageing3,4. Ultrasound treatment was carried out on sealed bottles of Buttafuoco red wine using an ultrasonic cleaning bath with 6oo W power at 40 kHz. Both short (5 min) and long (30 min) treatments were conducted twice weekly. Four break points were defined at 3, 6, 9, and 12 months, when chemical and sensory analyses were conducted. For profiling of wines, GC×GC-MS, LC-MS, CIELab, spectrophotometry, and multiparametric analyses were undertaken. For sensory analysis, the Triangle Test was undertaken at T3, and Qualitative Descriptive Analyses at T6, T9, and T12. Results have shown clear differentiation between the treatments in chemical composition, due to the duration of the treatment applied via ultrasound. This has also influenced basic parameters such as tartaric acid and sulfur dioxide levels. The overall pattern is complicated as non-linear effects were observed for specific species in relation to long and short treatments. Some compounds displayed a decrease for the short treatment with respect to the control (no treatment), but then showed an increase at long treatments with respect to the short treatments. In addition, the chemical compositions of all wines were also influenced by ageing over the time period. For example, acetic acid decreased with ageing but did not differ between treatments. Colour was also affected by ageing but not by treatment. The sensory results have not shown clear trends based on treatments, with the short treatments appearing to be somewhat distinctive, but with the long and control treatments clustering. Sensory results were also clearly influenced by ageing. It is suggested that ultrasound treatment has a potential application for accelerated ageing of commercial wines ahead of release to market. However, further study is recommended to gauge consumer preferences regarding the extent of treatment applied.