Evaluation of technological parameters in the production of beverages based on fermented plant ingredients

The aim of the study was to determine the optimal conditions for the fermentation of plant raw materials to ensure the stability and a favourable combination of sensory, microbiological, and physicochemical properties in beverages. The research was conducted under laboratory conditions and involved the fermentation of beverages from plant-based ingredients using both traditional and combined technologies. Physicochemical (pH, titratable acidity, redox potential), microbiological (counts of lactic acid bacteria and yeasts), and sensory parameters were monitored. It was found that combined fermentation resulted in a more rapid reduction in beverage pH (down to 4.0 within 72 hours) compared to traditional lactic acid fermentation (pH 4.6). The lowest pH (3.8) and highest titratable acidity (8.5 g/L) were observed in beverages based on fruit extracts, contributing to enhanced microbiological stability. Kombucha-based beverages exhibited intermediate acidity (6.5 g/L), while those produced from cereal substrates had the lowest acidity (5.7-6.0 g/L) and the shortest shelf life (10-12 days). Sensory analysis confirmed the advantages of combined fermentation: beverages produced using this method achieved a more complex aromatic profile and balanced taste, scoring 8.3 on a nine-point scale. Microbiological analysis revealed that yeast populations peaked at 48 hours (7.8 log CFU/mL) before declining, whereas lactic acid bacteria continued to increase until the end of fermentation (7.5-7.1 log CFU/ mL). Correlation analysis confirmed the influence of acidity on both microbial composition and sensory characteristics. The results demonstrated that combined fermentation leads to a more significant pH reduction, increased titratable acidity, and stabilisation of redox potential, thereby improving the microbiological stability and sensory quality of beverages. This approach enables the optimisation of functional fermented beverage production, enhancing organoleptic properties and extending shelf life