Nnko Dorcus, Mahadhy Ally
Department of Molecular Biology and Biotechnology, College of Natural and Applied Sciences University of Dar es Salaam Dar es Salaam Tanzania.
Food Sci Nutr. 2025 Aug 3;13(8):e70760. doi: 10.1002/fsn3.70760. eCollection 2025 Aug.
The increasing demand for functional beverages has driven interest in incorporating probiotics into fruit juices. This study investigates the functionalization of jamun juice with (), a thermophilic probiotic bacterium, to enhance its probiotic properties and assess storage stability under varying temperature conditions. was isolated from commercial yogurt and identified through colony morphology, Gram staining, and catalase and oxidase tests. The probiotic culture was cultivated in nutrient broth and inoculated into 250 mL of pasteurized jamun juice using 1 mL of bacterial suspension at a concentration of 1.5 × 10 CFU/mL, resulting in a final concentration of 6.0 × 10 CFU/mL in the juice. The functionalized juice was stored at 37°C (incubation), 25°C (room temperature), and 4°C (refrigeration) for 28 days, during which microbial load, pH, sugar content, antioxidant activity, and sensory acceptability were monitored. Results showed a significant increase in microbial load at 37°C, peaking at 10 CFU/mL by Day 14. At room temperature and refrigeration, microbial growth remained minimal, with levels around 10 to 10 CFU/mL. The pH declined most rapidly at 37°C, and at the same temperature, sugar content decreased to 2.2 mg/mL by Day 21. Antioxidant activity, measured using the DPPH assay, was highest (82.35%) at 37°C, indicating enhanced probiotic metabolic activity. Sensory evaluations revealed improved acceptability with lower temperature storage, particularly at refrigeration temperatures, while higher temperatures led to a decrease in sensory quality. Functionalizing jamun juice with improved its probiotic properties, with temperature playing a key role in maintaining these benefits. Refrigeration preserved both quality and probiotic stability, suggesting the potential of this probiotic jamun juice as a functional beverage. Future research could investigate its long-term stability, sensory characteristics, and nutritional profile, including the presence of bioactive compounds.
对功能性饮料日益增长的需求推动了将益生菌添加到果汁中的兴趣。本研究调查了用嗜热益生菌（）对印度醋栗汁进行功能化处理，以增强其益生菌特性，并评估在不同温度条件下的储存稳定性。从市售酸奶中分离出（），并通过菌落形态、革兰氏染色、过氧化氢酶和氧化酶试验进行鉴定。将益生菌培养物在营养肉汤中培养，然后使用浓度为1.5×10CFU/mL的1mL细菌悬液接种到250mL巴氏杀菌的印度醋栗汁中，使果汁中的最终浓度达到6.0×10CFU/mL。将功能化后的果汁分别在37°C（培养温度）、25°C（室温）和4°C（冷藏温度）下储存28天，在此期间监测微生物负荷、pH值、糖分含量、抗氧化活性和感官可接受性。结果表明，在37°C下微生物负荷显著增加，到第14天达到峰值10CFU/mL。在室温和冷藏条件下，微生物生长保持在最低水平，含量约为10至10CFU/mL。pH值在37°C下降最快，在相同温度下，到第21天糖分含量降至2.2mg/mL。使用DPPH法测定的抗氧化活性在37°C时最高（82.35%），表明益生菌代谢活性增强。感官评价显示，低温储存时可接受性提高，尤其是在冷藏温度下，而较高温度会导致感官品质下降。用（）对印度醋栗汁进行功能化处理可改善其益生菌特性，温度在维持这些益处方面起着关键作用。冷藏可保持品质和益生菌稳定性，表明这种益生菌印度醋栗汁作为功能性饮料具有潜力。未来的研究可以调查其长期稳定性、感官特性和营养成分，包括生物活性化合物的存在情况。
