Effect of microencapsulation with chitosan coating on survival of Lactobacillus casei and Bifidobacterium bifidum in ice cream

Microencapsulation with different hydrocolloids is currently used to promote the survival of probiotic bacteria in dairy products. This study encapsulated probiotics with chitosan coatings for ice cream، a dairy product stored at very low temperatures. Lactobacillus casei PTCC 1608 and Bifidibacterium bifidum PTCC 1644 were encapsulated using calcium alginate، resistant maize starch، and chitosan and then used to inoculate ice cream. The survival and effect of free and encapsulated bacteria on the sensory attributes of ice cream were monitored over 100 d of storage at -21°C. The morphology and size of the microcapsules were measured using optical microscopy and SEM. An increase in the number of surviving cells was observed because of the protection of cells by microencapsulation. The survival of microencapsulated probiotic bacteria coated with chitosan increased over uncoated cells (p < 0. 05). The incorporation of free and encapsulated probiotic bacteria do not substantially alter the overall sensory characteristics of the product. Microencapsulation with resistant maize starch and chitosan coating enhanced the survival of probiotic bacteria significantly in ice cream during storage compared to free cells.