Production of gelan-chitosan microgels crosslinked with genipin

Abstract

The addition and maintenance of functional ingredients have been quite studied since the population has been more concerned about the ingestion of functional foods for health and welfare. However, such functional ingredients might present instability during storage or digestion process, reducing their absorption. Microencapsulation allows to protect these bioactive compounds and to release them directly on the site of absorption, by controlling the composition of the capsule. Polysaccharides are widely used as encapsulating agents because they are non-toxic and biocompatible. The gellan is an anionic polysaccharide that forms firm gels at low concentrations and acid pH values, while chitosan is positively charged polysaccharide that shows mucoadhesive properties. However, chitosan gels are sensible to low pH values, it might be overcome by it crosslinking with genipin. The technique of extrusion/spray followed by ionic gelation allows to form stable microcapsules for application in foods products of high water activity. It would be interesting for products like yogurt and drinks. The combination of gellan microgel coated with chitosan crosslinked with genipin has great potential for microencapsulation due their resistance to low pH values, which is observed in most food products and in stomach digestion. Moreover, it can enhance the absorption of the bioactive compounds and therefore, it bioavailability. (AU)