matrix microencapsulation through air extrusion systems
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MICROINCAPSULAMENTO IN MATRICE ATTRAVERSO SISTEMI DI ESTRUSIONE IN ARIA
Candidato Marco Iasevoli
Matr. N06/125
Relatore Ch.mo Prof.Fabrizio Sarghini
ANNO ACCADEMICO 2012/2013
Matrix microencapsulation through air extrusion systems
Microencapsulation is the packaging of small particles of solid, liquid or gas, also know as the core, within a secondary material, also know as the shellor coating, to form small microparticles.
Spheres are usually classified in:
• Nanospheres (less than 100 nm)
• Microspheres (in the order of microns)
Protection of the active ingredients
Controlled Release
Mask unpleasant taste of certain
ingredients
Convert liquids to solids
Increase Shelf-life
Increase Bioavailability
GRAS Biocompatible Good barrier properties Cheap
Alginate in molecular terms is considered as a family of unbranched binarycopolymer of (14 linked β-D-mannuronic acid (M) and α-L-guluronic acid (G) residues.
Why Alginate?
The droplet breaks off when the gravitational force:
exceeds the surface tension induced counter force:
leading to a droplet diameter:
MEMS 2007 - 20th IEEE International Conference on Micro Electro Mechanical Systems, 21-25 January 2007
Experimental Conditions
Sodium alginate concentration (g/L)
15
Sodium Alginate flow rate (ml/minute)
0,20
Air mass flow rate (L/minute)
1
CaCl2 solutionConcentration (g/L)
20
CaCl2 solution mass flow (L/minute)
1
Surface tension (mN/m) 65
Reynolds Number (Re) 1174
Weber Numbe (We) 35
Air is costless There are only alginate
beads in hardening solution Easy wash with water No clog of device
Large quantity of oil means increased costs. Oil presence in hardening solution can give
coalescence of alginate bead Washing oil needs specific product Device can clog
• Taste masking
• Color masking
• Flavour Stabilization
• Novel food
Technological
• Fortified foods
• Functional foods
• Drug delivery in food matrix
• Controlled release
Healty
• Studies on live cell (e.g. Probiotics)Analytical
Encapsulation in the food sector is becoming even more important for its many applications. Sodium alginate has been chosen as matrix material because is regarded as:
•Biocompatible•Non-toxic•Biodegradable•Cheap
Some issues related to the scale-up procedure and polydispersity of the coaxial air flow technology still need to be addressed.
Nonetheless, this technology provide to food technologists a cheap, adaptable tool and a rapid prototyping platform for studies on microencapsulation through alginate.
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