Changes in textural parameters and microstructure of kombucha fresh cheese initiated by the addition of wild thyme

Using kombucha as a starter culture led to the successful production of fresh cheese in earlier research. Innovations in the dairy industry, the growing concept of circular economy and consumer demand for functional foods with extended shelf life led to the improvement of kombucha fresh cheese by adding wild thyme as a natural preservative. The aim of this study was to investigate the effects of wild thyme in the form of ground supercritical fluid extract and dry extract on the physicochemical and textural properties as well as the microstructure of fresh kombucha cheese during a thirty-day storage period. In terms of physicochemical properties, the greatest change was observed in the total protein content of the kombucha fresh cheese sample with the dry extract of wild thyme (from 23.21±0.15 to 23.77±0.24 %). In terms of textural properties, the greatest change was observed as a decrease in firmness in the control sample (from 5137.93±43.20 to 1955±16.39 g). PCA analysis showed that the pH values, which were determined for all samples after production, had the greatest influence on their firmness and work of shear. A slight disintegration of the kombucha fresh cheese structure was observed, due to the influence of storage time, proteolysis and the activity of the bioactive components of wild thyme.