MICROENCAPSULATION OF VITAMINS
Microencapsulation techniques enable a sustained and targeted release in the right place of the body as well as protecting the vitamins against destructive conditions either in the body or the ambient (Khazaei, Jafari, Ghorbani, & Kakhki, 2014; Mahdavi, Jafari, Ghorbani, & Assadpoor, 2014; Pourashouri, et al., 2014). Fig. 4.1 displays the types of microcapsules used for the microencapsulation of vitamins.
FIGURE 4.1 Microcapsule forms applied in vitamin encapsulation. Source: Reprinted with permission from Katouzian, I., & Jafari, S.M. (2016). Nano-encapsulation as a promising approach for targeted delivery and controlled release of vitamins. Trends in Food Science & Technology, 53, 34—48.
According to Gibbs (1999), the microcapsule size varies between 5 pm and 300 pm. The microcapsules may have a continuous payload phase encircled by a continuous shell or may have an irregular morphology with several tiny core particles dispersed in a network of shell material. Normally, the hydrophobic core is surrounded by a hydrophilic wall material and a hydrophilic core is surrounded by a hydrophobic wall material (De Prisco & Mauriello, 2016). The wall materials are responsible for protecting the vitamins against light, oxygen, and other factors that lead to the degradation of vitamins (Katouzian & Jafari, 2016; Wang, Vongsvivut, Adhikari, & Barrow, 2015).
The common microencapsulation techniques applied to the vitamins are explained briefly below. Furthermore, Table 4.2 summarizes the studies being conducted for the microencapsulation of vitamins.