3. ADVISORY COMMITTEE
CHAIRMAN Dr. S. KANCHANA, Ph.D.,
Professor,
Dept. of Food Science and Nutrition,
Home Science College & Res. Instt.,
Madurai-625 104.
MEMBERS Dr. G. HEMALATHA, Ph.D.,
Professor,
Dept. of Food Science and Nutrition,
Home Science College & Res. Instt.,
Madurai-625 104.
Dr. S. BALAKRISHNAN, Ph.D.,
Professor,
Dept. of Horticulture,
Agricultural College & Res. Instt.,
Madurai – 625 104.
Dr. M. R. DURAISAMY, Ph.D.,
Professor (Maths),
Dept. of Family Resource Management,
Home Science College & Res. Instt.,
Madurai-625 104.
4. Content
Introduction
Microencapsulation
Architecture of microencapsulation
Microencapsulation methods employed
in industry
Application in food industry
Recent development in microencapsulation of food ingredients
Controlled release mechanisms of food ingredients
5. Introduction
Microencapsulation is process of enclosing micron
sized particles in a polymeric shell (Desai & Park,
2005).
Microencapsulation means “encapsulation around
microscopic particles” (Mike, 2004).
Size - ranges -1 to 1000µm.
Firstly microencapsulation procedure - discovered -
Dutch chemist H.G. Bungenberg de Jong, in 1932 -
deal with the preparation of gelatine spheres -
coacervation process (Nupoor & Rathore, 2012).
6. Cont.,
Commercial product - microencapsulated dye by
NCR of American in 1953 (Complex coacervation).
Microencapsulation of cholesteric liquid crystal by
complex coacervation of gelatin and acacia
(thermosensitive ) – 1960 (Rama Dubey et al., 2009).
Not a new technology for food processing industry
7. Microencapsulation
Microencapsulation is a technique by which liquid
droplets (or) solids particles are coated with thin
film of protective materials. The droplets (or)
particles are called “core materials”. The thin film
coating is called “wall material”.
The film (or) wall material protects the “:core
material” against deterioration, evaporation of
volatile core (flavors) and also facilitates the
release of core under predetermined conditions
Natural example : eggs shells, plant seeds and sea
shells
8. Core and wall material
Core material
It is substance to be encased.
For example : solids, liquids (or) mixture of these such as
dispersion of solids in liquids, solutions and complex
emulsion have been used.
Wall material
To protect the corer material
The primer function - protect the core material against
deterioration and evaporation (losses) of the volatile.
9. Characteristics of the coating material
Good rheological properties at high concentration and easy work.
Ability to disperse or emulsify the active material and stabilize.
Non-reactivity.
Ability to seal and hold the active material.
Ability to completely release the solvent or other materials.
Provide maximum protection.
Solubility in solvents.
Chemical non-reactivity.
Inexpensive, food-grade status
11. cont.,
Category Coating materials Widely used methods References
Starch,maltodextrins, Spray- and
chitosan, freeze-drying,
Carbohydrate Reineccius (1991)
corn syrup solids, extrusion,
dextran, modified Coacervation and
starch, cyclodextrins inclusion
complexation
Carboxymethylcellulose,
methyl cellulose, Coacervation and
Cellulose Reineccius (1991)
ethylcellulose, spray-drying
celluloseacetate-phthalate,
celluloseacetatebutylate-
phthalate
Gum acacia, agar, sodium Dziezak (1991)
Gum alginate, carrageenan Spray-drying
Wax, paraffin, beeswax,
diacylglyerols, oils, fats Inclusion complexation
Lipids Kim and Baianu1(1991)
Gluten, casein, gelatin, Inclusion complexation
Protein albumin, peptides and spray-drying Dziezak (1991)
12. Cont.,
Gibbs et al. (1999) - Gum Arabic (GA) - increase the
retention of volatiles and shelf-life of microcapsules -
excellent solubility and surface active properties.
McNamee et al. (2001) - GA + MD - better
emulsification characteristics and oxidative stability.
Gibbs et al. (1999) - MD - poorer emulsification
properties (lower viscosity & lack of lipophilic groups).
Zhu et al. (1998) - Gelatin - good emulsification
properties, film formation, water-solubility and
biodegradation.
13. Cont.,
Francoise et al. (2012) - Vegetable proteins (PPI, SPI,
wheat gliadins, corn zein and barley protein. ) -
Widely used.
Expected product objectives and requirements
Nature of the core material
Process of encapsulation
Economics
It should be approved by FDA (Kuang et al., 2010).
14. Reasons for microencapsulation (Rathor and Mudaliar, 2012 )
Enhances the overall quality of food products.
Reduces the evaporation or transfer of the core material to the
outside environment.
Superior handling of the active agent.
Effectively retains volatile components particularly flavours.
Provides - incorporating vitamins, minerals and oxygen-
sensitive oils - palatable and shelf-stable food products.
Improved stability in final product and during processing.
Control release of the active components.
Masks the aroma, flavour, and colour of some ingredients.
18. Cont.,
Technology Morphology Particle size (μm)
Spray-drying Matrix 10–400
Spray-chilling/ cooling Matrix 20–200
Co - crystallization Matrix
Fluid bed coating Reservoir 5 - 500
Coacervation Reservoir 10–800
Inclusion complexation Molecular inclusion 0.001– 0.01
RESS Matrix 10–400
Freeze- or vacuum Matrix 20–5,000
drying
Centrifugal suspension Reservoir 30µm to 2mm
extrusion
Centrifugal extrusion Reservoir 250μm to few mm
(Nicolaas and Shimoni, 2010)
19. SPRAY-DRYING
One of the oldest processes
Spray-drying of active agent is commonly achieved
by dissolving, emulsifying, or dispersing the active in
an aqueous solution of carrier material, followed by
atomization and spraying of the mixture into a hot
(Gharsallaoui et al., 2007).
Economical process
Readily available equipments and uses flexibly
Produce good quality particles & particles size ranges
between 10 -400μm
20. Schematic diagram of spray drying process
Core material Wall material
Homogenise
Inlet temperature -150 -200oC
Outlet temperature- 115 to
130oC
150 -
Atomizer speed – 30,000rpm
Feed rate – 20 to 45ml/min
21. Cont.,
Commonly used shell materials include gum
acacia, maltodextrin and hydrophobically modified
starches.
Rice and wheat starch - applied with small amount
(0.1 to 1.0% ) bounding agent (Protein or hydrophilic
polysaccharides )(Zhao & Whistler, 1994).
Other polymers including
alginate, carboxymethylcellulose (CMC), guar gum
(GG) and proteins – (expensive, low solubilities, much
larger evaporation and presence of core material on
the surface of microcapsules ) (Desai et al., 2005).
22. 2011
Aim : The analysis and stability of microencapsulated folic acid during the
processing and preparation of instant Asian noodles.
Method : Prepared of microencapsulated folic acid by spray drying with
combination of alginate and pectin as a wall material.
Result : Microencapsulation of folic acid with combinations of alginate and
pectin as the binding agents, proved to be effective in maintaining folic acid
stability after spray drying. Study recommended - Microencapsulated folic
acid (7mg) was successfully incorporated in Asian noodles (300 g of flour)
and Virtually no FA lost during boiling in moderate periods. Readily
measurable losses (only extended periods of heating).
23. Cont.,
20µm
FA encapsulated with Alginate
& Pectin
24. SPRAY-CHILLING OR SPRAY-COOLING
Core and wall mixtures are atomized into the cooled
or chilled air-causes- wall to solidify around the
core.
To produce lipid-coated active agent.
Does not involve evaporation of water.
Spray-cooling - vegetable oil or its derivatives
Others fat and stearin - melting points of 45–122oC
- hard mono- and diacylglycerols - melting points of
45–65oC.
25. Cont.,
Spray – chilling - fractionated or hydrogenated
vegetable oil with a melting point of 32–42oC.
Microcapsules - insoluble in water due to the lipid
coating.
These techniques - utilized for encapsulating water-
soluble core materials such as minerals, water-
soluble vitamins, enzymes and some flavors.
Particle size – 20 to 200µm
26. FLUIDISED-BED COATING (Hammad et al., 2011)
Otherwise called air suspension coating.
Originally developed - pharmaceutical technique - now
increasingly - applied in the food industry (Gouin, 2004).
Encapsulating solid or porous particles with optimal heat
exchange.
Principle
The liquid coating is sprayed onto the particles and the
rapid evaporation helps in the formation of an outer layer
on the particles.
27. Cont.,
Great variety of coating materials - Cellulose
derivatives, dextrins, lipids, protein derivatives, and
starch derivatives.
Yield relatively defect-free coatings.
Particles size – 5 to 500µm.
Three types (Top spray, Bottom spray, and Tangential
spray).
28. Top- spray fluidized - bed coating
Coating material is
sprayed downwards onto
the fluid-bed.
Coating
solution
Increased encapsulation
efficiency and prevention
of cluster formation.
Produce higher yields.
Inlet air flow
29. Bottom- spray fluidized - bed coating
Its also known as “Wurster’s
coater (Prof. D.E. Wurster). Wurster chamber
Coating chamber - cylindrical
nozzle and a perforated bottom
plate.
Spraying the coating material
and particles move upward
Nozzle
direction.
Desired thickness and weight is Perforated bottom plate
obtained.
Time consuming process -
multilayer coating - reducing
particle defects.
30. Tangential- spray fluidized - bed coating
Consists of a rotating
disc at the bottom of the
coating chamber.
Disc is raised to create a
gap. Coating
solution
Particles move through Rotating
the gap into the spraying disc
zone and are
encapsulated.
31. Aim: To investigate microencapsulation of probiotic by Air – suspension
Fluidized – Bed Coating method using Trehalose and MD as a wall
material.
Methods : Trehalose + MD + DW – heated at 93oC – cooled addition
dry probiotic culture – spray coating in the sir suspension process.
Results: Trehalose and maltodextrin provided enhanced protection of
the probiotic cells during the air-suspension drying process and further
enhanced the stability of the coated particles during storage (28days).
Particels size - 20µm.
32. COACERVATION
Latin ›acervus‹, meaning “heap”.
Made Via - liquid-liquid phase separation
mechanism.
Simple coacervation and complex coacervation .
Frequently used shell material – GA and Gelatin.
Particle size - 10–800µm
33. Schematic representation of complex coacervation
Isopropanol
& H 2o
to 5 - 10oC
Dried by
SD &FD
(Nicolaas and Shimoni , 2010)
34. Aim: To investigate microencapsulation of olive oil by complex
coacervation method using gelatin A with sodium alginate as a wall
material.
Methods : Gelatin + olive oil - mechanical stirring + addition Na
alginate - temperature lowered - Cross linking - washing (Hexane &
H2O) - FD.
Results: Maximum coacervation occurred at 3.5:1 gelatin to sodium
alginate ratio and at pH of 3.75. The encapsulation efficiency was found
to increase - increase in the concentration of olive oil, glutaraldehyde
and polymer. SEM - the size of the microcapsules were increased as the
amount of olive oil and polymer concentration increased.
Particels size - 0.5µm.
35. CENTRIFUGAL SUSPENSION SEPARATION
More recent microencapsulation
process.
Continuous and high-speed
method – Highly suitable for
foods.
Taken a few seconds.
Widely used coating materials -
fats, polyethylene glycol (PEG)
and diglycerides.
Particels size – 30 µm to 2mm.
(Swapan Kumar, 2006)
36. CENTRIFUGAL EXTRUSION (Raouf Ghaderi, 2000)
Wall materials - gelatin,
sodium alginate,
carrageenan, starches,
cellulose derivatives,
gum acacia, fats / fatty
Core
acids, waxes, and
polyethylene glycol. Wall
Produced larger size,
from 250 microns up to
a few millimeters in
diameter.
37. POLYMER ENCAPSULATION BY RESS
What's SCF ?
Widely used SCF - Co2.
Highly suitable for processing heat-sensitive materials.
Non-toxic, non-flammable, inexpensive and reasonably high
dissolving power.
Other SCF (Ethylene. Ethane, Propane, Ammonia, Isopropanol,
Cyclohexane and Benzene).
Pesticides, pigments, pharmaceutical ingredients, vitamins, flavors,
and dyes.
Paraffin wax, acrylates, polyethylene glycol, proteins and
polysaccharides
40. FREEZE-DRYING AND VACUUM DRYING
Lyophilization –dehydration of heat sensitive materials
and aromas.
Water-soluble essences and natural aromas as well as
drugs (Except for the long dehydration period).
Sample frozen (-90 to -40oC) - Dried by direct sublimation-
Grinding, if necessary.
Disadvantages – Particle Size – 20µm to 5mm.
Vacuum-drying - very similar to freeze-drying, but
operates at a temperature above the freezing point of the
solvent (>0 C in case of water) - faster and cheaper.
(Shami and Bhasker, 2009)
41. Aim : Passion fruit juice was encapsulated in Capsul® and stored at
different temperatures and analysed stability of vitamin C.
Method : Passion fruit juice was filtered - mixed with 20% Capsul®
and freeze-dried. The encapsulated passion fruit power was stored at
7, 25, and 37 C, in the dark, for 12 weeks and analysed Vitamin C
stability.
Results : Very stable microcapsules (homogeneous white powder
with strong and pleasant smell of passion fruit). 91.4, 81.1, and
36.2% vitamin C retained after 12 weeks, samples stored at
7, 25, and 37 C. Particle size - an average 205.7 0.09 μm.
42. Cont.,
Cont.,
(1µm)
205.7 0.09 μm
Microencapsulated Passion fruit juice (Capsul®)
45. Cont.,
Three methods to produce the flavor or oil - β-cyclodextrin
complex.
β-cyclodextrin - dissolved in H2O - added flavour -
Crystallin form- dried.
β-cyclodextrin - dissolved in a lesser amount of H2O.
β-cyclodextrin - dissolved in a much lower H2O- Kneading.
Use of β-cyclodextrin in food application- very
limited, possibly due to regulatory requirements in a
number of countries.
(Barreto et al., 2011)
46. Aim : The aim of the present study was to prepare the inclusion
complexes of the Cinnamomum verum essential oil with β-
cyclodextrin in various ratios (5:95, 10:90, 15:85 and 20:80
(w/w).
Result : The retention of essential oil volatiles and maximum
inclusion efficiency (94.18%) of β-cyclodextrin was achieved at
the ratio of 15:85, in which the complex powder contained 117.2
mg of oil/g of β-cyclodextrin - commercially acceptable .
47. CO-CRYSTALLIZATION
New encapsulation process .
Widely used core material – Sucrose.
Flow-chart of co-crystallization process
Sucrose syrup Addition of
(supersaturated state ) core material
Crystallize Nucleation Vigorous
Mechanical
agitation
Agitation is continued Agglomerates are discharged Dried
(Sanjoy Kumar Das et al., 2011)
48. APPLICATION IN FOOD INDUSTRY
Current trend - healthier way of living.
Improve nutritional value by adding ingredients.
Overcome all these challenges by microencapsulation.
Incorporate minerals, vitamins, flavours and essential
oils.
Simplify food manufacturing process, decreasing
production costs , extend shelf-life, help fragile and
sensitive.
50. Aim : To study the microencapsulation of Garcinia cowa fruit rinds extract by
spray drying technique using whey protein isolate as a wall material. The effects
of different outlet temperatures (90 & 105oC) of the spray dryer and wall-to-
core ratios (1:1 & 1.5:1) and HCA retention were also studied.
Result : Microencapsulation efficiency (HCA recovery 94.49 %) and
antioxidant Properties (flavonoids and xanthones) were higher at 90 C
outlet temperature of the spray dryer using 1.5:1 wall-to-core ratio.
Incorporation of this powder in pasta had higher antioxidant activity as
well as better cooking and sensory characteristics.
51. Aim : To evaluate the influence of the wall materials based on maltodextrin
and whey protein isolate on the efficiency of the microencapsulating process
via spray-drying and retention of ginger oil in microcapsule.
Method : Ginger oil (steam distillation) + Wall solutions (mixture of WPI
and 18DE MD) = spraydried (inlet and outlet air temperature of 120 3 C
and 60 3 C )
Result : High MEE (99.36% )and ginger oil (93.30% 0.1%) at optimum
conditions 1:1 ratio of WPI to MD, 1:4 ratio of core to wall material, and
total solid content of 25%.
53. • Aim : To explore the possibility of delivering omega-3 PUFA-rich oils using
different types of microemulsion and investigated the conversion of ALA to
long chain omega-3 PUFA when given to rat as microemulsion.
• Method : LSO/SNO was encapsulated in microemulsions using gum
acacia, whey protein and lipoid - feed (Male Wistar rats) 1 mL of LSO (46
mg of LA) or SNO (41 mg of ALA) for 30 days – Blood (cardiac
puncture), serum (centrifugation) and liver (removed) – analyzed.
• Result : ALA absorption (LSO) enhanced, ALA converted to EPA & DHA
(microemulsion in lipoid) in rat. LSO microemulsion (lipoid) - (41 and 34
µg/ml)EPA &DHA found in serum. LSO microemulsion (lipoid) – enhanced
uptake of ALA - conversion to long chain omega-3 fatty acids in liver lipids
56. Controlled, Sustained or Targeted release of core material.
Release of the core material - involve one or a combination
of stimuli.
Number of factors affect release – (nature of the coating
and the core material, , capsule size, capsule
storage, application as well as capsule structure).
Diffusion membrane controlled
Pressure activated Tearing peeling
pH sensitive Temperature sensitive
Osmotically controlled
57. Cont.,
Diffusion – diffusion controlled by solubility of compound in the matrix
& permeability of the matrix to the compound.
Core diffusion rate - Chemical structure, thickness, pores size and
surface integrity .
Pressure activated release - Pressure applied on the walls of the
microcapsules.
pH sensitive release - microcapsule coating or matrix contains chemical
bonds - cleaved -pH value .
Temperature sensitive release - Melting of the capsule wall (lipids or
waxes) to release the active material.
Osmotically controlled release- Utilising osmotic pressure. (Eg. If
encapsulated core material has a high affinity for water – larger internal
pressure – core material released (Gibbs et al., 1999).
59. References
• Rodney Hau. (2011). The analysis and stability of microencapsulated folic acid during
the processing and preparation of instant Asian noodles. Thesis of Doctor of
Philosophy, School of Applied Sciences Science, Engineering and Technology
Portfolio RMIT University.
• Sanjoy Kumar Das, Sheba Rani Nekka David and Rajan Rajabalaya. ( 2011).
Microencapsualtion Techniques and Its Practice. Int J of Pharam Sci Tech, Vol (6): 1-
23.
• Kashappa Goud H. Desai and Hyun Jin Park. (2005). Recent Developments in
Microencapsulation of Food Ingredients. Drying Technology, 23: 1361–1394.
• Sharma Nupoor and Rathore KS. (2012). A Review on Microencapsulation: A New
Multiutility Advanced Technology. International Journal of Advanced Research in
Pharmaceutical and Bio-Sciences, Vol.1 (4):477-489.
• Goran M. Petrovic, Gordana S. Stojanovic and Niko S. Radulovic. (2010).
Encapsulation of cinnamon oil in β-cyclodextrin. Journal of Medicinal Plants
Research Vol. 4(14), pp. 1382-1390.
60. Cont.,
• Daniela Borrmann, Selma Gomes Ferreira Leite, and Maria Helena
Miguez da Rocha Leao . (2011). Microencapsulation of Passion Fruit
(Passiflora) Juice in Capsul®. International Journal of Fruit
Science, 11:376–385.
• D. Sugasini • B. R. Lokesh. (2012). Uptake of a-Linolenic Acid and Its
Conversion to Long Chain Omega-3 Fatty Acids in Rats Fed
Microemulsions of Linseed Oil. Springer, AOCS.
• Dipin S. Pillai, P. Prabhasankar, B.S. Jena, and C.
Anandharamakrishnan. (2012). Microencapsulation of garcinia cowa
fruit extract and effect of its use on pasta process and quality.
International Journal of Food Properties, 15:590–604.
• Alhassane Touré, Hong Bo Lu, Xiaoming Zhang and Xu Xueming.
(2011). Microencapsulation of Ginger Oil in 18DE Maltodextrin/Whey
Protein Isolate. Journal of Herbs, Spices & Medicinal Plants, 17:183–
195.