Microencapsulation – A review summarizes microencapsulation as a method for encapsulating active food ingredients like vitamins, flavors, and oils in micro- or nanoparticles to protect them during processing and storage. Various microencapsulation techniques are discussed, including spray drying, extrusion, coacervation, and liposome formation. The selection of technique depends on the properties of the active ingredient and wall material. Microencapsulation helps address issues like nutrient degradation, incompatible ingredients, and texture changes in food products. It allows for controlled release and stability of sensitive compounds in foods.

1. Microencapsulation – A review
Dr. Thomas P. Zafiriadis
DVM – Food Technologist MSc.,
Professor in Culinary Technicians’ and Chef’s Department
Katerini’s Public Institution for Professional Training (IEK), Director of ESTIA LAB
Abstract: The quest for new methods providing safer and healthier food products, which retain all the essential dietary components, such as vitamins, and their organoleptic properties,
has led to the development of microencapsulation, i.e. the method of encapsulating active and sensitive to processing compounds in food products in the form of micro - or nanoparticles.
In order to achieve this, microencapsulation uses several techniques, such as spray drying and cooling, extrusion, fluidizing bed, coacervation, alginate beads formation, liposome
formation, RESS/SAS and inclusion encapsulation. The selection of appropriate method depends on the characteristics of the active ingredients, the wall material and the cost of
application. In the near future, food industry will depend on microencapsulation and biotechnology for its development.
Key words: microencapsulation, spray drying, spray cooling, extrusion, co-acervation, fluidized bed, liposomes, ellagitannins, nanoparticles, biopolymers.
1. INTRODUCTION:
Since the appearance of human kind on earth, there is a constant effort for inventing new methods not only for better food preservation, but also for the transfer of valuable nutrients and
drugs with the food. Nowadays, the food industry is increasingly focusing on the incorporation of components that provide a health benefit to the customer in food products. Such valuable
substances, which can be extremely vulnerable to low pH values, like the ones in stomach, are enzymes, flavors and oils. The most common and noninvasive mode of administration of
these substances is via the oral route. The intestinal delivery of such vulnerable substances deserves special attention, since the slightest change in conformation of the molecule can be
detrimental to its properties. However, the intestinal delivery is severely hampered due to the highly acidic environment in the stomach. One of the most significant methods that can be
used in dealing with this problem is microencapsulation (Jafari et al, 2008, Lambert et al, 2008).
4. DISCUSSION:
Some of the technical difficulties encountered by industries - and solved by microencapsulation application - are:
The loss of product functionality during processing, storage and/or commercialization.
The lack of compatibility between functional substance and food matrix, something common in the
case of fat soluble vitamins in aqueous foods.
The development of undesirable flavors or strange odors due to added bioactive compound
degradation. Marine oils, for instance, prone to undergo oxidization.
The control of the modification of food product texture as a consequence of the added compound, in
order to achieve the manufacture of an acceptable product from a commercial point of view.
The need for adapting the production line for the incorporation of a new substance which often implies
the complete change of parameters involved in the process.
In the case of enzymes, the short operational life or the inactivation undergoing of the dissolved ones
due to their sensitivity to processing or trace levels of substances that can actuate as inhibitors (Lopez
- Rubio et al, 2006).
2. DEFINITIONS:
a process in which the cells are retained within an encapsulating matrix or membrane, i.e. the
active ingredients (core materials) are packaged in a secondary (wall) material (Jafari et al, 2008;
Hambleton et al, 2008; Hsieh et. al., 2009).
microsize particles that consist of capsule material an encapsulated component and can be
prepared by methods such as freeze and spray drying, with the latter being the most commonly
encapsulation technique used for food products (Jafari et al, 2008, Laine et al, 2008).
3. METHODS AND MATERIALS:
Methods
Spray
drying
Spray
cooling/
chilling
Fluidized
bed
Spinning
disc
co-
extrusion
Co-
acervation
RESS/
SAS
Inclusion
en-
capsulation
Methods
Encapsulated
Materials
Encapsulation Material Attributes Equipment
Spray drying
encapsulation
Flavor oils Liposomes
Protection against degradation/
oxidation
Spray dryer
Spray cooling/
chilling
Salts, textural ingredients, enzymes,
flavors
Liposomes and monoglycerides Stability improvement and delay release Spray cooler
Fluidized bed
Polysaccharides, proteins, emulsifiers,
fats, complex formulations, ascorbic acid,
acidulants
Alginates Protection and longer shelf life
Spinning disc
co-extrusion
Polysaccharides, proteins, emulsifiers, fats Alginates Protection and longer shelf life
Modified double fluid nozzle
on spray towers
Co-acervation
Flavor oils, fish oils nutrients, vitamins,
preservatives, enzymes
Gelatin/gum acacia system. gliadin, heparin/gelatin,
carrageenan, chitosan, soy protein, polyvinyl alcohol,
gelatin/carboxymethyl-cellulose, starch, – lactoglobulin /gum
acacia, and guar/dextran
5. REFERENCES:
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stability of nattokinase using - polyglutamic acid as a coating material for microencapsulation.
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