MICROENCAPSULATION OF FOOD FLAVORS

The size of microcapsules containing flavors may span from a few millimeters to less than 1 pm (Gouin, 2004; Jafari et al., 2008). Microcapsules may comprise one or a set of compounds forming the whole carrier structure. Normally, the generated microcapsules are added to larger systems so as to be adjusted to the intended system. A broad range of substances is employed to encapsulate flavors, which include lipids, carbohydrates, proteins, natural, and synthetic gums plus other biopolymers (Jafari et al., 2008; Rajabi, Ghorbani, Jafari, Mahoonak, & Rajabzadeh, 2015; Reineccius, 1988). Besides, with the rapid progress of knowledge and technology, different materials and their combinations are used as encapsulants to preserve flavors and increase the shelf life of products. In order to encapsulate flavor compounds, the micro-vehicle must not react with the payload, have a simple

TABLE 7.3 Some Wall Materials Applied to Encapsulate Flavors

structure to be handled, i.e., can flow and does not exhibit high viscosity, protect the bioactive core against surrounding medium, and possess desirable emulsion-stabilization features plus effective dispersion performance so that flavors are released in the right place and time (Castro et al., 2016; Trubiano & Lacourse, 1988). Here, some of the typical wall materials applied for the microencapsulation of flavors are represented in Table 7.3. Finally, the properties of food components, such as polysaccharides, lipids, and proteins and their interactions with flavors should be carefully studied to design an effective delivery system (McClements, Decker, Park, & Weiss, 2009).

With the development of the encapsulation science, novel technologies are being invented for use in industrial scales. Flavors are encapsulated via different methods, and generally these techniques can be classified into chemical and physical processes (Fig. 7.2). Among these methods, spray

FIGURE 7.2 Different microencapsulation techniques employed for flavor molecules.

drying and extrusion are broadly employed in the food industry for food flavors as they are straightforward and cost-effective (Chew & Nyam, 2016; Jafari et al., 2008; Mahdavi et al., 2014; Rajabi et al., 2015).