Microencapsulation and sonication: A multiple physical approach to attenuate the probiotic Lacticaseibacillus casei ATCC 393.

Modulation of probiotic performances represents a tool to avoid the probiotic off-flavor in probiotic food. Microencapsulation and sonication were evaluated in slowing down the Lacticaseibacillus casei ATCC 393 induced acidification. Firstly, the influence of alginate concentration and chitosan coating on acidification rate were tested. Microcapsule morphology and the entrapment efficacy were also evaluated. Then, two time of exposure to ultrasound, 6 and 8 min, were applied for L. casei attenuation. Finally, sonicated cells were encapsulated. ΔpH after 6 and 24 h of incubation at 37 °C revealed that chitosan-alginate microcapsules and the 8-min sonicated probiotic presented a significant delayed acidification. When all the systems were compared, the encapsulation of 8-min sonicated L. casei in chitosan-alginate microcapsules significantly improved the results obtained with the single technologies. These results suggest that by modulating the operating parameters and combining these two technologies an increasingly efficient attenuation system can be developed.