Edible carrageenan films enhance flavour encapsulation

By Stephen Daniells, 08-Apr-2009

Related topics: Science & Nutrition

Combining fat and iota- carrageenans could form edible films for flavour encapsulation, says fundamental new research from France and Spain.

Encapsulating aroma compound in iota-carrageenan fat led to modification to the structure on both sides of the film, thereby affecting the permeability, according to findings published in the Journal of Food Engineering.

"This study on the relative encapsulation of aroma compound by the fat and by i-carrageenan matrix leads to promising potential applications for flavour encapsulation as well as flavouring by using food surface coating technologies," wrote the researchers.

Microcapsules are tiny particles that contain an active agent or core material surrounded by a shell or coating, and are now increasingly being used in food ingredients preparation. The technology can be used to deliver a host of ingredients - flavours, oils, peptides, amino acids, enzymes, acidulants, colours and sweeteners - in a range of food formulations, from functional foods to ice cream.

The technology is attracted growing interest because it can also decrease costs for food makers, particularly those using sensitive ingredients like probiotics, and by reducing the need for preservatives.

Study details

The researchers, led by Frédéric Debeaufort from the University of Burgundy, investigated how factors such as microstructure, composition, surface properties and the different interactions affect the release of flavour from iota-carrageenan microcapsules.

Iota-carrageenan (Cargill) emulsion-based edible films were formulated with anhydrous glycerol (Fluka Chemical) as the plasticizer, a fat (GBS, Danisco Bradbrand) to act as the carrier of the flavour compound (n-hexanal), and glycerol monostearate (GMS, Prolabo Merck eurolab) as the emulsifier.

According to their findings, the edible iota-carrageenan films exhibited good emulsion stability and mechanical properties, and reduced the transfer of oxygen, and therefore spoilage of the flavour.

The results also showed that interactions between n-hexanal and iota-carrageenan and n-hexanal and fat has an effect of the surface structure on both sides of the film. This would affect the permeability, said the researchers.

"The encapsulated n-hexanal interacts with CH2OH and/or sulphated groups of i-carrageenan lateral chains inducing a lower permeability," said Debeaufort amd his co-workers. "The addition of fat also induces the formation of aggregated globules which decreases the aroma permeability."

Take home message

"This study develops new understanding of the influence of the composition and structure of the matrix of films on aroma barrier properties and surface absorption characteristics," wrote the researchers.

"The addition of additives and other active molecules causes interactions with the film matrix, inducing changes in the film properties from one side to another."

Source: Journal of Food Engineering
Volume 93, Issue 1, Pages 80-88
"Interface and aroma barrier properties of iota-carrageenan emulsion–based films used for encapsulation of active food compounds"
Authors: A. Hambleton, M.-J. Fabra, F. Debeaufort, C. Dury-Brun, A. Voilley