The use of live microbial agents, or probiotics, as dietary adjuncts is currently a subject of intense and growing interest. Probiotics have been defined as “Probiotics are live microorganisms which, when administered in sufficient amount, confer a health benefit to the host” (Ararya, 2005). Beneficial bacteria, such as Lactobacillus acidophilus and Bifidobacterium species., can be found worldwide in a variety of products, including convent ional food products and dietary supplements.
Keep their health-promoting properties
One of the most important prerequisites for use of probiotics is that they survive and keep their health-promoting properties throughout the production process or during technological food treatment and storage until the end of shelf life. Moreover, because viable and biologically active microorganisms are usually required at the target site in the host, it is essential that probiotics withstand the host’s natural barriers against ingested bacteria.
Improve the survival of probiotics during the food manufacturing process
Among the different approaches proposed to improve the survival of probiotics during the food manufacturing process and the passage in the upper part of the GI tract, microencapsulation has received considerable attention. Cell immobilization generally tends to increase the viability and the stability of microorganisms during their exploitation.
However, efficiency can vary according to the method used and the culture considered. In almost all cases, gel entrapment using natural biopolymers such as calcium alginate and kappa-carrageenan has been favored by researchers for probiotic applications (Picot, 2004). Although promising on a laboratory scale, the technologies developed to produce gel beads present all serious difficulties for large-scale production (Poncelet, 1996).
Development of cell encapsulation technologies
In addition, encapsulation in such matrices does not necessarily protect efficiently the cells from the effect of pH, organic acids, or other soluble compounds like oxygen that can easily diffuse in a very hydrated medium. Consequently, the development of cell encapsulation technologies that use effective, food-grade, and economic coating materials, constitutes a real priority to generalize the use of encapsulated probiotics in the food and feed industries.