In this study, probiotic bacteria such as Lactobacillus acidophilus and Bifidobacterium bifidum were encapsulated in alginate beads with a mean diameter of 54.25 ± 0.18 µm by internal gelation. Encapsulated and free cells as control samples were then added to the pasteurized grape juice and stored for 60 days. At the end of the storage period, the survivability of the bacteria in the encapsulated samples was significantly ( P<0.05) higher than that in the free cells (8.67 ± 0.12 and 7.57 ± 0.08 log cfu mL-1 for L. acidophilus and 8.27 ± 0.05 and 7.53 ± 0.07 log cfu mL-1 for B. bifidum for encapsulated and free forms, respectively). The results generally showed a decrease in °Brix, pH, and color, whereas acidity and turbidity have increased the in probiotic grape juice after the storage period of 60 days. For all treatments, the numbers of surviving cells were more than the recommended minimum (107 cfu g-1) at the end of the storage period.
Keywords: Probiotics; encapsulation; grape juice; organoleptic properties.