The scientists note that the discovery could be of interest to the cosmetic industry as due to the growing popularity of supplements with cosmetic and beauty functions.
It is also said to be of interest to the food and pharmaceutical industries.
"This study demonstrated that encapsulation had an excellent capacity to protect bioactive molecules against temperature, humidity, and acidic conditions and allowed a controlled release of these compounds during gastrointestinal transit," wrote the researchers, led by Monique Lacroix from the Institut National de la Recherche Scientifique (Institut Armand-Frappier) in Laval, Canada.
"Therefore, the potential use of this new encapsulation method could be further explored and could be of great interest for cosmetic, pharmaceutical, and food uses."
New development Alginate and chitosan are already employed for encapsulation since they can form gels in the presence of mineral ions like calcium, state the researchers in background information in the article.
"Nevertheless, gel erosion is an important problem of alginate beads because it accelerates the release of the encapsulated substance," they added.
Lacroix and co-workers successfully developed the new encapsulation matrix consisting of alginate and chitosan by functionalising the non-toxic, biodegradable, and biocompatible polymers by a chemical reaction - acylation - with palmitoyl chloride.
The functionalised beads were compared with normal alginate-chitosan beads.
Acylation of the polymers led to the formation of palmitoylated alginate in the core of the beads and palmitoylated chitosan on the external layer.
This increased the elasticity and water impermeability of the beads.
In order to test the applicability of the new encapsulation method, the researchers conducted a release study in a solution that resembled gastrointestinal conditions.
The functionalised encapsulated beads were "not susceptible to enzymatic and acidic attacks during transit in the stomach," they stated.
Moreover, a controlled release of the micronutrients was observed for the functionalised beads with slower release between 30 min and two hours, compared to the normal beads, and faster release between two and four hours.
Source: Journal of Agricultural and Food Chemistry Published online ahead of print, ASAP Article, doi: "Alginate and Chitosan Functionalization for Micronutrient Encapsulation" Authors: J. Han, A.-S. Guenier, S. Salmieri, M. Lacroix