Effect of refrigerated storage on the probiotic survival and sensory properties of milk/carrot juice mix drink

Background : There is a genuine interest in the development of probiotic milk and juice based beverages because they are a good-vehicle to deliver probiotic microorganisms to consumers. For this purpose, the viability and metabolism of four probiotic strains ( Lactobacillus acidophilus LA5, Bifidobacterium lactis BB12 , L. rhamnosus and L. plantarum ) were studied in non-fermented milk and carrot juice mix drink. The drinks were evaluated in 5 days interval for viable cell count, pH, acidity, sedimentation and sensory quality during refrigerated storage at 4 ± 2ºC for up to 20 days. Results: The results showed that all strains had good viability in milk/carrot juice drink (88-98%), but L. acidophilus LA5 seemed more stable than three other strains. The levels of pH and acidity were ranged 5.33-6.6 and 0.13-0.31%, respectively. The drinks inoculated with L. rhamnosus and control (non-probiotic) showed more variation in pH and acidity. The most sedimentation was detected in drinks inoculated with L. rhamnosus , reaching 3.73 mL/10 mL sample. Sensory assessment indicated lowest acceptability in control and milk/carrot juice drink inoculated with L. rhamnosus, respectively. Conclusion : This study indicated that some probiotic bacteria can be applied by food producers to produce functional drinks with an increased shelf-life.