Influence of high power ultrasound on Brettanomyces and lactic acid bacteria in wine in continuous flow treatment

• The HPU treatment showed reduction in Brettanomyces yeast as well as in LAB.
• Less than one minute of HPU treatment for the 90% reduction of Brettanomyces yeasts.
• Slightly longer than one minute of ultrasound treatment for the 90% reduction of LAB.
• Sensory testing of the HPU treated wine samples shows an impaired aroma of wine.

The purpose of this study was to investigate the effect of non-thermal technology, a high power ultrasound (HPU) in continuous flow treatment on the reduction in number of Brettanomyces yeasts and lactic acid bacteria (LAB) in wine samples. Yeast cells and lactic acid bacteria were screened for their sensitivity to a high power ultrasound treatment using an ultrasonic processor (400 W, 24 kHz, 100 μm amplitude) at two different wine temperatures (30 and 40 °C). High power ultrasound treatment in continuous flow showed satisfactory reduction of Brettanomyces yeasts (89.1–99.7%) and lactic acid bacteria (71.8–99.3%). Sensory properties of wine were impaired. The results indicate a great potential for the application of HPU in continuous flow system for wine processing in terms of lower usage of SO2 and preservatives. More attention is needed to preserve sensorial properties of wine.