delivery systems are often expensive. There are other options for protection, such as controlling food matrix properties (e.g., nutrients, pH, ionic strength, temperature, oxygen, other properties that affect bacterial survival) and selecting resistant microbial strains (e.g., bile- and acid-resistant strains, strains resistant to some of the other stressors to which bacteria are likely to be exposed). Third, any potential delivery system used should not adversely affect the desirable quality attributes of a food, such as appearance, taste, texture, and shelf life, because this will affect the likelihood that an individual will continue to purchase and consume the food.
In many respects, McClements noted, developing delivery systems for probiotics is similar to what drug manufacturers do when they develop delivery systems for drugs. However, the challenge is even greater because of greater constraints on the types of components that can be used with foods and the complexity of the food matrix. A drug can be placed in a capsule, pill, or syrup, but a probiotic, if it is going to be consumed regularly, needs to be placed in a food matrix in such a way that it does not adversely affect the appearance, taste, texture, or stability (shelf life) of the food, according to McClements. Plus, food products encounter a series of