Encapsulation of Aromas

Aromas can be protected against the chemical changes described in 5.5.4 by encapsulation. Materials suitable for inclusion are polysaccharides, e. g., gum arabic, maltodextrins, modified starches, and cyclodextrins. The encapsulation proceeds via spray drying, extrusion or formation of inclusion complexes. For spray drying, the aroma substances are emulsified in a solution or suspension of the polysaccharide, which contains solutizer in addition to the emulsifying agent. 

In preparation for extrusion, a melt of wall material, aroma substances, and emulsifiers is produced. The extrusion is conducted in a cooled bath, e. g., isopropanol. 

P-Cyclodextrins, among other compounds, can be used for the formation of inclusion complexes (cf. 4.3.2). Together with the aroma substances, they are dissolved in a water/ethanol mixture by heating. The complexes precipitate out of the cooled solution and are removed by filtration and dried. Criteria for the evaluation of encapsulated aromas are stability of the aroma, concentration of aroma substance, average diameter of the capsules and, amount of aroma substance adhering to the surface of the capsule. 

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Encapsulation of aroma compoimds in amorphous carbohydrate matrices can be carried out, for example, by freeze- or spray-drying (Levine et al., 1991 Roos, 1995). Aroma compounds often remain encapsulated in glassy carbohydrate matrices stored at temperatures below their glass transition. Release of encapsulated aroma compounds may occur when amorphous carbohydrate matrices are stored at temperatures above their glass transition, allowing sufficient molecular mobility and diffusion. 

Lyophilization or freeze-drying is a simple technique that is suitable for the encapsulation of aromas, water-soluble essences, drugs, and importantly used for the dehydration of almost all heat-sensitive materials. It is a process that requires a long dehydration period. The retention of volatile compounds during lyophilization is dependent upon the chemical nature of the system. ... 

Zuidam, N. J. and E. Heinrich. Encapsulation of aroma. In Zuidam, N. J. andNedovic, V. Eds., Encapsulation Technologies for Active Food Ingredients and Food Processing, pp. 127-161. New York Springer (2010). 

Marcuzzo, E., Debeaufort, F., Hambleton, A., Sensidoni, A., Tat, L., Beney, L., VoUley, A. 2011. Encapsulation of aroma compounds in biopolymeric emulsion emulsion-based edible films to prevent oxidation. Food Research International. 

The objective was to encapsulate a vegetable oil (representing a model for aroma compound) into a powder. The oil (ISI04) (VO) will be at a concentration of 5% TS into a matrix made of maltodex-trin MD (DE 12) and acacia gum (AG) (3/2 MD/AG). The composition of matrix was defined in a previous research work on encapsulation of aroma by spray-drying (Bhandari et al., 1992 Turchiuli et al, 2005 Fuchs et al, 2006). 

Sediment stabilization in fruit juices, obtaining body in beverage powders Stabilization of powdery tiroma emulsions, encapsulation of aroma substances... 

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