3.2.4. Starch Use for Probiotic Delivery

Starch can be used as an encapsulating agent but it has weaker characteristics than alginate, chitosan, or cellulose. In the pharmaceutical field, starch is used mainly for encapsulating drugs or active substances when molded into tablets or oral formulations. This is because starch is strongly hydrophilic and is easily dissolved in liquids at ambient temperatures. However, it has the ability to form very small microspheres constituted in resistant aggregates, allowing for a better protection of the core [218]. For example, when used as an encapsulating agent for *L. plantarum*, rice starch maintained cell viability both at 4 ◦C (refrigeration conditions) and at temperatures above 50 ◦C. However, as an encapsulating agent, starch proved to be more effective when mixed with other compounds. For example, the combination of starch and alginate resulted in microcapsules with increased probiotics resistance to simulated gastric conditions (Table 7).




3.2.5. Cellulose Use for Probiotic Delivery

Carboxymethyl cellulose (CMC) is one of the most widely used forms of cellulose due to the fact that it is the most affordable in terms of spread and cost. Although it is a compound that prevents lipid oxidation and reduces oxygen permeability due to the small number of hydroxyl groups in the structure, CMC is a highly water-soluble compound. This limits its use as an encapsulation material for probiotics as it is degraded in the digestive system. Therefore, when used in combination with other biopolymers such as polysaccharides (carrageenan, alginate, chitosan, and starch), proteins (gelatin), or other natural compounds (inulin), it increased the viability of encapsulated anaerobic probiotics by 36% [227]. The microencapsulation characteristics of CMC have been improved due to the addition of other substances such as gelatin or carrageenan. In general, the encapsulated probiotics maintained their viability for 120 min in simulated gastric conditions, regardless of the type of probiotic encapsulated. When lyophilization was used as the encapsulation method, cellulose and alginate maintained the viability of *L. plantarum* for approximately 160 days in refrigeration conditions (Table 8).

**Table 8.** Cellulose as a probiotic encapsulating material.



Abbreviations: CMC, carboxymethyl cellulose; SGF, simulated gastric fluids; SIF, simulated intestinal fluids; CFU/g, colony-forming unit per gram; and CFU/mL, colony-forming unit per milliliter.
