Encapsulated probiotic cells: Relevant techniques, natural sources as encapsulating materials and food applications - A narrative review

The administration of probiotic microorganisms in adequate amounts is constantly related to health benefits. To promote beneficial effects, these microorganisms must not be affected by exposure to environmental factors and must be able to adhere and colonize the human gastrointestinal tract. Several encapsulation techniques and encapsulating materials are available to produce probiotic particles, however, it is essential that the process must not be aggressive, reducing or preventing injuries and cell losses, besides, the particle properties obtained must be adequate for the proposed purpose. At the same time, the global market for supplements and probiotic foods has been growing significantly, and cell encapsulation appears as an alternative to incorporate probiotics into different food matrices. This review discusses and updates the main techniques, and the traditional and emerging polysaccharides for encapsulation of probiotic cells, as well as the advantages and possibilities of incorporating produced particles into food matrices. Currently, various scientific studies report the use of different encapsulation techniques, such as extrusion, emulsion, spray drying, spray chilling and fluidized bed to encapsulate probiotics properly. The alginate is still widely used to produce probiotic particles, however, there has been a growing interest in its total or partial substitution with others polysaccharides, such as gums, mucilages, prebiotic compounds and microbial exopolysaccharides, which improve the protection and survival of encapsulated cells and allow their incorporation into dairy and non-dairy food products.