COMPARATIVE ASSESSMENT OF FERMENTATION PROPERTIES AND QUALITY CHARACTERISTICS OF FERMENTED PRODUCTS FROM PLANT-BASED MILK ALTERNATIVES

Abstract

The growing demand for plant-based dairy alternatives has intensified research on their technological suitability for fermented product development. This study aimed to comparatively evaluate the fermentation behaviour and quality characteristics of cow’s milk and commercially available plant-based beverages, including soy, oat, coconut-rice, and almond-rice drinks, under identical fermentation conditions using a mixed lactic acid starter culture. Fermentation was carried out at 38-42 °C for 12 h, and the dynamics of active and titratable acidity, as well as structural and sensory properties of the resulting products, were assessed. Additionally, density measurements and sensory profiling were performed to characterize textural development and consumer-related attributes. The results demonstrated significant differences in acidification kinetics among the investigated substrates. Cow’s milk exhibited the most intensive fermentation, reaching a final titratable acidity of 95.7 °T and a pH of 4.6. Soy-based beverage showed the most favourable fermentation performance among plant-based samples, achieving a final titratable acidity of 82.7 °T and forming a stable coagulum with density of 1.035 g/cm³. Oat beverage demonstrated moderate fermentation activity, while coconut-rice and almond-rice systems showed limited acid production and weak structural development. These differences were primarily associated with variations in protein content, carbohydrate composition, and buffering capacity of the studied matrices. In particular, reduced buffering capacity in plant-based systems contributed to accelerated pH decline, which may negatively affect microbial activity and gel network formation during fermentation. Sensory evaluation confirmed that cow’s milk yogurt possessed the most balanced organoleptic profile, whereas soy-based fermented product most closely resembled traditional yogurt, although it retained characteristic plant-derived flavour notes. Oat, coconut-rice, and almond-rice products were characterized by weak gel structure, pronounced whey separation, and lower sensory acceptability. The findings indicate that titratable acidity is a more reliable indicator of fermentation progress in plant-based systems than pH alone, due to differences in buffering behaviour. Overall, the comparative assessment highlights substrate-dependent limitations in gel formation and confirms soy-based beverage as the most promising plant matrix for yogurt-type fermentation under conventional conditions. The study provides technological insights for optimizing formulation strategies of plant-based fermented products and contributes to the development of dairy alternatives with improved structural and sensory quality