Influence of interactions on water and aroma permeabilities of ι-carrageenan-oleic acid-beeswax films used for flavour encapsulation

The objective of this work is to investigate the water and aroma barrier properties of films obtained from iota-carrageenan containing glycerol and lipids mixtures of oleic acid (OA) and beeswax (BW) used for encapsulation of active compounds. Water vapor permeability (WVP) is greatly influenced by lipid composition, encapsulated aroma compound and also relative humidity. WVP decreases when films contain encapsulated aroma compound but increases when the moisture content in the films increases. When oleic acid was the main compound of lipid phase, the plasticizing effect of water revealed through water permeability is less marked. The results of ethyl acetate, ethyl butyrate, ethyl hexanoate, 2-hexanone, 1-hexanol and cis-3-hexenol permeabilities reveal that physicochemical interactions between aroma compounds-hydrocolloid and aroma compound-lipid induce structural changes and modify their permeability. This work gives evidence of the ability of iota-carrageenan-OA-BW films to protect encapsulated aroma compound and its influence in barrier properties. (C) 2008 Elsevier Ltd. All rights reserved.