Effect of Thermosonication and Physicochemical Properties of Wine on Culturability, Viability, and Metabolic Activity of Yeast in Red Wines.

The aim of this research was to investigate the short- and long-term effects of thermosonication and different physicochemical properties of wine on culturability, viability, and metabolic activity of yeast. Thermosonication was conducted at 43 °C during 1, 2, and 3 min, while wine variations included several pH, alcohol, and sugar levels. Cell culturability and viability were determined immediately after treatment and during 90 days of storage, while metabolic activity was determined after 90 days of storage. Results showed that, although culturability was not confirmed in dry wines immediately after 3 min of treatment, thermosonication did not result in complete inactivation of the population. Herein, the first evidence of a viable but not culturable (VBNC) state of after thermosonication exposure was observed. Moreover, thermosonication reduced the production of volatile phenols. Obtained results suggest application of thermosonication for reduction of the population only in early stages of wine contamination.