Probiotics are a type of active microorganisms that are beneficial to human health. Since the bacteria are highly sensitive to the external environment, problems such as low survival rate or poor biological activity are prone to occur during production, storage, and use, which greatly reduces the probiotic effect of probiotics. Encapsulation technology can protect probiotics from environmental and related factors to a certain extent and has a good effect on probiotics resisting adverse external conditions. In recent years, the rapid development of probiotic encapsulation technology has provided an effective strategy for the efficient protection of probiotics. At present, the cutting-edge technologies for encapsulating probiotics mainly include four types: endogenous emulsification method, Pickering emulsification method, composite coagulation method, and multi-layer embedding method. Among them, multi-layer embedding technology mainly includes double-layer embedding and three-layer embedding. With the optimization of process conditions, four-layer embedding technology has gradually become a research hotspot.
To date, the pinnacle of multilayer particle complexity is the four-layer structure that provides maximum protection for encapsulated probiotics. The four-layer particles used for encapsulation can be self-assembled layer by layer, or self-assembly can be combined with microencapsulation technology. combine. Lactobacillus valericum was encapsulated in four-layer particles using positively charged chitosan and negatively charged sodium phytate, and the survival rate of probiotic bacteria in double-layer and four-layer structures in simulated gastrointestinal fluid was determined. The results showed that in gastric juice (pH 1.5) and bile salt solution (pH 6.8), the number of viable bacteria embedded in four layers was twice as high as that in two layers. In these two solutions, The reason for the decreased survival rate of probiotics embedded in four layers may be related to the lower thickness of the coating. Therefore, to pursue a higher survival rate of probiotics, the emulsification method can be used to encapsulate the probiotics in alginate particles, and then these particles are deposited layer by layer through chitosan-alginate-chitosan. Achieve the purpose of four layers of coating. Single alginate particles and four-layer microparticles were tested in a liquid that simulated the upper gastrointestinal tract environment in vitro, and the viability of probiotics was measured. The results showed that the four-layer encapsulated probiotics not only improved the viability of the probiotics, but also improved the Metabolic functions of probiotics during oral absorption, passage through the gastrointestinal tract, and transport to the ileum and colon.
Four-layer microcapsule encapsulation technology provides a unique platform for the targeted delivery of probiotics to the colon, but care should be taken that the thickness of the encapsulation should not be too high, otherwise, it will prolong the lag time and interfere with the growth dynamics of probiotics.
references:
[1] Chen Chen, Zhang Xiaocong, Yuan Haibin, et al. Probiotic encapsulation cutting-edge technology and research progress [J]. Chinese Journal of Food Science, 2023, 23(01): 384-396. DOI: 10.16429/j.1009-7848.2023. 01.037.
[2]Sepehr T, Timothy S, Peter V, Aaron S, John M. K., Qayyum A, Fariba D, 2022. Biopolymer-Based Multilayer Microparticles for Probiotic Delivery to Colon. Advanced Healthcare Materials, 11, 2102487. DOI: 10.1002/adhm .202102487.