Nanoencapsulation of Flavors

Mohsen Asghari Ghajari12, Iman Katouzian12, Mohammad Ganjeh1 and Seid Mahdi Jafari1

1Gorgan University of Agricultural Sciences and Natural Resources, Gorgan, Iran, 2Nano-encapsulation in the Food, Nutraceutical, and Pharmaceutical Industries Group (NFNPIG), Universal Scientific Education and Research Network (USERN), Tehran, Iran

INTRODUCTION

Encapsulation is a method applied to encase one or a mixture of bioactive compounds (core material) within another ingredient (shell/wall material). The advent of microencapsulation dates back to 1950, where it was exerted in fabricating pressure-sensible coatings in non-carbon copying paper (Green, 1955). Encapsulation technique has undergone a variety of changes, and currently it is applied in food, chemical, pharmaceutical, cosmeceuticals, printing, and many other sectors (Lakkis, 2007). Until now, different food components have been micro/nanoencapsulated in order to produce functional foods, as well as preserving the volatile and delicate compounds such as enzymes, colorants, vitamins, oleoresins, aromas, and, especially, flavors (Dubey, 2009; Jafari, Assadpoor, He, & Bhandari, 2008; Jafari, He, & Bhandari, 2007b; Mahdavi, Jafari, Ghorbani, & Assadpoor, 2014; Pourashouri et al., 2014b).

Flavorings are substances in the food that are responsible for their unique taste and odor. Some of these flavors present in different food products include allylpyrazine in roasted nut, methoxypyrazines in vegetables, 2-Isobutyl-3 methoxypyrazine in green pepper, acetyl-L- pyrazines in popcorn, aldehydes in fruits, terpenoids in citrus and piney, and phenolics in smoked products (Cardinal, Cornet, Serot, & Baron, 2006; Coetzee et al., 2015; Ling, Yang, Li, & Wang, 2015; Sharma, Utreja, & Bedi, 2016; Sidhu, Lund, Kotseridis, & Saucier, 2015; Zhu, Xiao, Zhou, & Lei, 2015). Due to the instability of most flavor structures, encapsulation seems to be a logical means to preserve the properties of these compounds.

The encapsulation procedure for flavors is summarized in two steps as follows: first, emulsification is applied to the payload like a lipid-based aroma using a carrier material made from polysaccharide or protein. In the second phase, the

Nanoencapsulation of Food Bioactive Ingredients. DOI: http://dx.doi.org/10.1016/B978-0-12-809740-3.00007-6

© 2017 Elsevier Inc. All rights reserved.

Simple illustration of microspheres and microcapsules

FIGURE 7.1 Simple illustration of microspheres and microcapsules.

emulsions are dried or cooled (Janda, Bernacchi, & Frieders, 1995; Mahdavi, Jafari, Assadpoor, & Dehnad, 2016). An illustration is provided for the flavor encapsulation in Fig. 7.1, which can be either in microcapsules or microspheres. Several physicochemical factors are responsible for the retention and controlled release of flavors, like molecular weight, polarity, and composition of the carrier material, etc. These parameters make possible the targeted release as well as preserving the bioactives against undesirable conditions inside and outside the body (Augustin, Sanguansri, Margetts, & Young, 2001; Gibbs, 1999; Jafari et al., 2007b; Jafari et al., 2008; Katouzian & Jafari, 2016). Regarding the implemented encapsulation technique, the encapsulants may have different shapes, such as spheres, disordered shapes plus films, and also the formed structures may be either compact or porous. All these factors together determine the diffusion pace of encapsulated flavors as well as oxygen and solvents penetration into the shell from outside. Before going through the techniques used for encapsulation of food flavors, a brief overview of food flavors is needed.

 
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