Engineering of capsules with controlled permeability

Introduction:

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.

Goal:

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 µm 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