Process for encapsulating active agents in gels

The present invention relates to a process for encapsulating an active agent in a biopolymer in the form of a gel, comprising the steps of: a) forming a dispersion or solution of the biopolymer in water; and b) adding the active agent to the dispersion or solution obtained in step a); wherein the biopolymer is at least partially dissolved before and/or after addition of the active agent. The gels obtained with the present invention are particularly suitable for coating or impregnating packaging materials

Composition for the controlled release of active compounds

he invention provides a composition for the controlled release of one or more biologically active substances encapsulated in a degradable biopolymer matrix, consisting of a thermoplastic and/or partly crystalline inulin. A plasticiser such as glycerol, and an emulsifier may be present. The active substance is e.g. a drug, a biocide, a fertiliser, a flavour, a protein or a microorganism

Effect of glycerol on the morphology of starch-sunflower oil composites

The presented study involves the encapsulation of sunflower oil in starch by casting emulsions of oil in aqueous starch solutions. Glycerol was used as a plasticizer and lecithin was used as an emulsifier, to improve the emulsion stability. Increasing glycerol concentration in the samples resulted in different dispersed phase morphologies in the starch-sunflower oil composites. It was observed that increasing glycerol concentration resulted in a decrease in the particle sizes and polydispersity of the oil droplets. The two determining parameters on the formation of the dispersed phase during emulsification; viscosity and interfacial tension between two phases, were investigated to evaluate the effect of glycerol on the system. Since glycerol was found not to affect the viscosity of the aqueous starch phase, it was concluded that glycerol affects the dispersed phase morphology due to its effect on interfacial tension between the oil and aqueous starch phase, during emulsification

Encapsulation of ?-amylase in a starch matrix

In this study thermostable ?-amylase was encapsulated in a pregelatinized potato starch to obtain a controlled degradation upon water uptake. Encapsulation was performed using kneading, a (thermo) mechanical process. The aim of the study was to evaluate the possibility to encapsulate a degrading enzyme for a system, which can be triggered to degrade upon water uptake instead of direct water contact. After the encapsulation process, the enzyme (?-amylase) activity in the samples was found to have 90 ± 5% of activity of the unprocessed enzyme. It was seen that there was initial degradation of the starch matrix during processing, proportional to the enzyme concentration. The encapsulated enzyme was inactive during storage under low humidity conditions (RH ? 60%) and could be reactivated upon water uptake by incubation of samples in humid atmosphere (90% RH). The reduction of the molecular weight, upon activation of the encapsulated enzyme was also proportional to the concentration of the encapsulated enzyme. © 2002 Elsevier Science Ltd. All rights reserved