Delivery systems for liquid food products

One of the present challenges of the food industry is to deliver nutrition and health benefits to the consumer while keeping, or improving the taste and aroma impact. Adding active ingredients to liquid food products for fortification is in most cases not possible or not sufficient to achieve the desired goal, due to the fact that many interesting micronutrients are only hardly soluble in aqueous systems and show (i) a limited stability against chemical or physical degradation, (ii) an incompatibility between the active ingredient and the food matrix, or (iii) reveal an uncontrolled release or bioavailability. Therefore, encapsulation systems, also denoted as ‘delivery systems’, are typically used to solve these formulation problems. The task to find the appropriate delivery system is especially challenging for the food industry compared to other fields such as pharmacy, medical products or cosmetics, since only a limited amount of ingredients can be used as encapsulation and stabilization material. In the present review we will discuss the delivery systems available for (semi)-liquid foods and comment on existing advantages and limitations. The remaining technical challenges to solve in the future concern mainly the facts that (i) most of the available delivery systems for aqueous products do not yet allow to significantly stabilize degradation sensitive ‘encapsulated’ active ingredients against e.g. oxidation, (ii) the ‘encapsulation’ (solubilization) capacity of some delivery systems is still quite poor and (iii) off-taste generation is possible above certain concentrations of added delivery systems.