Immobilisation of bifidobacteria in biodegradable food-grade microparticles

Delivery of Probiotic-Loaded Microcapsules in the Gastrointestinal Tract: A Review

Probiotics are live microorganisms that inhabit the gastrointestinal tract and confer health benefits to consumers. However, a sufficient number of viable probiotic cells must be delivered to the specific site of interest in the gastrointestinal tract to exert these benefits. Enhanced viability and tolerance to sublethal gastrointestinal stress can be achieved using appropriate coating materials and food matrices for orally consumed probiotics. The release mechanism and interaction of probiotic microcapsules with the gastrointestinal tract have been minimally explored in the literature to date. To the authors' knowledge, no review has been published to discuss the nature of release and the challenges in the targeted delivery of probiotics. This review addresses gastrointestinal-related complications in the formulation of targeted delivery and controlled release of probiotic strains. It investigates the impacts of environmental stresses during the transition stage and delivery to the target region in the gastrointestinal tract. The influence of factors such as pH levels, enzymatic degradation, and redox conditions on the release mechanisms of probiotics is presented. Finally, the available methods to evaluate the efficiency of a probiotic delivery system, including in vitro and in vivo, are reviewed and assessed. The paper concludes with a discussion highlighting the emerging technologies in the field and emphasising key areas in need of future study.

Bifidobacteria Encapsulation and Viability of Probiotic Culture during Oral Delivery in a Milk Drink Matrix

The use of an alginate hydrogel exclusively for the immobilization of bifidobacteria during oral delivery led to a decrease in the total number of bifidobacteria to 4.0 lg CFU/ml in pH gradients in models of the stomach and intestines, which required clarification of the composition of the protective coating. The introduction of resistant starch into the composition of the microcapsule contributed to the preservation of the viability of immobilized bifidobacteria up to 87% of the initial concentration when passing through the model environment simulating the human digestion system. The introduction of sodium carboxymethylcellulose into the composition of the hydrogel contributed to the regulation of the degradation of the polymer matrix and the controlled release of bifidobacteria. The use of sodium carboxymethylcellulose 0.5% in the formation of a polymer microcapsule provided the maximum encapsulation efficiency of 93.2% and the maximum decay rate of bacteria-loaded microcapsules of 95.7%. The modified alginate matrix contributes to maintaining the level of viable cells of probiotic microorganisms (Bifidobacterium bifidum 791) of at least 108 CFU/g when stored for three weeks. As a result of the research, a system for oral delivery of immobilized bifidobacteria in the structure of microparticles with a closed surface in the matrix of a milk drink has been developed, which increases the effectiveness of probiotics for human health in the composition of food products.

Exploring the roles of starch for microbial encapsulation through a systematic mapping review

Microorganism encapsulation protects them from stressful conditions and assists in maintaining their viability, being especially beneficial when the carrier material is a renewable and biodegradable biopolymer, such as starch. Here, a systematic mapping was performed to provide a current overview on the use of starch-based systems for microbial encapsulation. Following well-established guidelines, a systematic mapping was conducted and the following could be drawn: 1) there was a significant increase in publications on microbial encapsulation using starch over the past decade, showing interest from the scientific community, 2) ionotropic gelation, emulsification and spray drying are the most commonly used techniques for starch-based microbial encapsulation, and 3) starch play important functions in the encapsulation matrix such as assisting in the survival of the microorganisms. The information gathered in this systematic mapping can be useful to guide researchers and industrial sectors on the development of innovative starch-based systems for microbial encapsulation.