Engineering of capsules with controlled permeability


Encapsulation of micronutrients such as probiotic bacteria are interesting for food industry. The design of suitable capsule materials with tailor-made properties, and development of mild encapsulation techniques with controlled encapsulation efficiency is still quite challenging. Micro-organisms to be encapsulated require a shell material with poor H+-transporting properties. The mechanical properties of the capsules determine the diffusion and release of core material; therefore rigidified oil capsules could be more beneficial than simple fluids.


Figure 1: Schematic presentation of structured oil capsules in presence of lecithin and STS gelators.


The structured oil capsules can be prepared by using organogeltors such as lecithin and STS at elevated temperature and cooling down at lower temperature. Recently cross-flow membrane emulsification is explored as an advanced encapsulation technique. We use a variety of micro-engineered membranes to prepare monodisperse capsules with tunable size.


Figure 2: a) Microsieve with 5 ┬Ám size pores b) Monodipserse w/o/w double emulsion prepared with this microsieve emulsification.

Fields of interests:
Double emulsions in presence of  various organogeltors
Encapsulation technology with controlled encapsulation efficiency, membrane emulsification