Survival and stability of free and encapsulated probiotic bacteria under simulated gastrointestinal conditions and in ice cream

The aim of the present study was to evaluate the upshot of microencapsulation on the stability and viability of probiotics in carrier food (ice cream) and simulated gastrointestinal (GIT) conditions. Purposely, Lactobacillus casei was encapsulated with two different hydrocolloids, that is, calcium alginate (Ca-ALG) and whey protein concentrate (WPC) by using encapsulator. The obtained microbeads were characterized in terms of encapsulation efficiency and morphological features. Afterward, the probiotics in free and encapsulated form were incorporated into ice cream. The product was subjected for physicochemical, microbiological, and sensory attributes over a storage period of 80 days. Microencapsulation with both hydrogels significantly (p < .05) improved the viability of probiotics in both carrier food and simulated GIT conditions.The initial viable count of probiotics encapsulated with Ca-ALG and WPC was 9.54 and 9.52 log CFU/ml, respectively, that declined to 8.59 and 8.39 log CFU/ml, respectively, over period of 80 days of storage. While nonencapsulated/free cells declined from 9.44 to 6.41 log CFU/ml during same storage period. Likewise, during in vitro GIT assay, encapsulated probiotic with Ca-ALG and WPC showed 0.95 and 1.13 log reduction, respectively. On other hand, free probiotics showed significant 3.03 log reduction. Overall, microencapsulated probiotic exhibited better survival as compared to free cells. Moreover, the amalgamation of encapsulated and free probiotics affected the physicochemical (decrease in pH and increase in viscosity) was and sensory parameters of ice cream during storage.