Development of a synbiotic water kefir, dragon fruit, and inulin–medium-chain triglyceride drink as a candidate for an antihyperlipidemic beverage

Consumer demand for palatable functional beverages with metabolic health benefits is increasing. Water kefir is a plant-based probiotic drink associated with improved metabolic profiles, immune modulation, and anti-inflammatory effects. Combining probiotics with prebiotics (synbiotics) may further enhance these benefits, although synbiotic beverages remain underdeveloped. This study aimed to develop and characterize a synbiotic water kefir beverage formulated with red dragon fruit and 20% inulin–medium-chain triglycerides (MCTs) as a potential Indonesian functional beverage. Physicochemical stability (pH and viscosity) was evaluated during 95 days of production. Microbiological safety ( Salmonella and Escherichia coli ), sensory acceptability, titratable acidity, total phenolic content, ethanol concentration, carbohydrate content, and cholesterol-lowering activity in an obesity-induced mouse model were assessed. The beverage exhibited stable physicochemical properties (pH 4.18 ± 0.01; viscosity 197.8 ± 0.15 cP) throughout production. Salmonella and E. coli were not detected. Hedonic evaluation indicated overall acceptance, with all attributes scoring ≥3 (“liked”); the dragon fruit color received the highest score, while fermented aroma was acceptable but scored lowest. Total phenolics reached 2.514 ± 0.333 mg GAE/100 mL, titratable acidity was 0.399% ± 0.054%, ethanol content was 0.44% ± 0.0026% (w/w), and carbohydrate content was 22.73% ± 0.38% (w/w). In obese mice, the synbiotic beverage significantly reduced total cholesterol levels. The dragon fruit 20% inulin–MCT synbiotic water kefir is microbiologically safe, sensorially acceptable, and physicochemically stable, with antioxidant potential and cholesterol-lowering activity in vivo , supporting its potential as a functional beverage.