The development and characterization of a plant-based functional beverage using Rebaudioside-A

Background: Excessive sugar intake is a major global health issue, fuelling non-communicable diseases and driving consumer demand for nutrient-rich, low-calorie beverages without artificial additives. Functional beverages (FB) present an effective solution by conveniently delivering targeted health benefits. Rebaudioside-A (Reb-A), a natural, zero-calorie sweetener derived from Stevia rebaudiana, provides a promising alternative to sugar and artificial sweeteners, enabling the development of all-natural, low-calorie FBs. Objective: This study aimed to develop a FB with soluble fibre, in two versions: one sweetened with sugar (SSB) and another with Reb-A (RAB), and compare their sensory, physicochemical, and functional properties. Methods: Both SSB and RAB were prepared from pomegranate, raspberry, and lemon juices, as well as green tea, coconut water, and inulin. The beverages were pasteurized (85°C, 1 min) and stored at 3–4°C. Analyses included pH, total soluble solids (TSS), water activity, colour, antioxidant properties (FRAP, total phenolic content-TPC, DPPH, and total anthocyanin content-TAC), and sensory evaluation using a 9-point hedonic scale for taste, odour, colour, and overall acceptance. Results: The RAB finished product demonstrated higher antioxidant activity, with higher DPPH scavenging (p<0.05) and increased FRAP values (p<0.05) compared to SSB. Both beverages presented the same pH, TPC, TAC, water activity levels, and inulin content (5.5 g/serving). Sensory evaluations revealed an overall preference of 70.5% for SSB (p = 0.001), although female participants (42% of the cohort) showed no significant preference. Acceptability indices were high for both (SSB: 83.4%, RAB: 76.9%; p = 0.003), with RAB scoring above 6/9 across all attributes. There were no differences in colour or odour between the two beverages Novelty of the Study: This study is among the first to systematically develop and compare functional beverages (FBs).