Stress tolerance and physicochemical properties of encapsulation processes for Lactobacillus rhamnosus in pomegranate (Punica granatum L.) fruit juice.

Encapsulation of Lactobacillus rhamnosus was performed using spray and freeze-drying. Maltodextrin and gum arabic were used in different combinations for spray-drying. Values of 50% maltodextrin and 40% gum arabic gave best results. Spray-drying was done at temperatures ranging from 110 to 150oC. Survivability, acid tolerance, antibiotic sensitivity testing, and total anthocyanin content and physical properties of moisture content, water activity, color analysis, bulk density, and tap density were analyzed. The moisture content of encapsulated powders ranged from 6.51 to 7.72% (wet basis) and bulk density and tap density values ranged from 0.334 to 0.308 g/cm3 and 0.350 to 0.330 g/cm3, respectively. Total anthocyanin contents were 19.28 and 7.264 mg/100 mL, respectively, for freeze and spray-dried powders. Freeze-dried probiotic pomegranate juice powder yielded best results with high survivability of Lactobacillus rhamnosus, a high total anthocyanin content, and other properties.