Meat + Poultry - January 2004 - 44

based on temperature, the chocolate coating, or the encapsulating material, dissolves in your mouth and releases the cherry filling, the ingredient. For a quick release using agitation, all the consumer has to do is bite into the product, which releases the filling
immediately.

encapsulating material and the temperature at which the process operates. Spray-cooled products tend to use products that have melting points in the range of 45° - 65°C, whereas the materials selected
for spray chilling are in the 32° - 42°C range. Spray-chilled products
form almost perfect spheres, yielding free-flowing powders. Products
that are spray chilled include vitamins, acidulates, ferrous sulfate,
solid flavors and ingredients that are heat sensitive. The selection
Encapsulate options
of the encapsulation material is important when using these techTo produce encapsulated ingredients, manufacturers have the op- niques. The proper mixture of fats allows the ingredient manufacturer
tion of using several different processes. These include spray drying, to control the melting point of the encapsulated ingredient and hence
spray chilling, spray congealing and fluid-bed micro-encapsulation.
its point of release during its use.
Spray drying is perhaps the oldest encapsulation technique.
A third process for manufacturing encapsulated flavors is the fluAmong the materials that are manufactured using the spray drying idized bed process. This process allows processors to control the
process are yeast and soy protein extracts. Spray driers remove wa- thickness of the coatings, the size of the encapsulated granules and
ter from solutions, suspensions or emulsions to produce powders produce custom products for different end users. This technology is
that have moisture contents that approach equilibrium with the dry- often used in manufacturing encapsulated ingredients. The technoling air. There are three techniques used
ogy works best with dense particles that
for creating the fine drops needed for
have good flow characteristics.
Encapsulating attributes
proper spray drying. These are highThe ingredient or material to be enpressure atomization, centrifugation and
capsulated is placed in a chamber where
When selecting an encapsulating
two-fluid atomizing. The latter proceit remains suspended in columns of air.
compound look for:
dure is expensive and used most often
The temperature and humidity of the
for products that are difficult to atomize.
chamber is rigidly controlled to assure
1. Good emulsifying properties
The first step in spray drying is to select
that the finished product has the desired
2. Low cost
the proper encapsulating compound.
characteristics. Once the encapsulated
The encapsulating compound must be
material reaches the target temperature,
3. Low hygroscopic properties
mixed with the ingredient at the proper
the coating material is introduced as an
4. Film formers
levels. The level of solids in the emulsion
atomized spray, the droplets of which are
5. Low viscosity at high solids levels
or dispersion is essential to ensure that
smaller than the flavor or ingredient. The
the desirable properties of the ingrediturbulence of the air keeps the substrate
6. Bland taste release the ingredient
ents are retained. Excessively low-level
suspended and tumbling, and as they
in the food
solids can result in losses. Prior to drymove the coating material deposits on
7. Ingredient protection
ing, the emulsion must be homogenized.
the surface. The materials being coatThis will help to ensure the flavor or the
ed move just like convection currents in
ingredient is retained within the encapa fluid system; they rise toward the top,
sulation materials. The homogenized mixture is then sprayed or move toward the outside of the chamber and drop into the fluidized
thrown using a centrifuge into the drying chamber. Hot air and small bed where the process is repeated until the particles are coated.
droplets combine to dry the product quickly. The dried ingredient is Residence times in the chamber range from two to 12 hours. It is
then collected and packaged. Due to the nature of the spray-drying this feature of the process that allows the manufacturer to control the
process, most products of the process are water soluble. One con- amount of coating materials that is deposited on the surface. The
cern that manufacturers have with this technology is the potential for fluidized bed system has an advantage in that processors can use
clumping, which can adversely affect how the ingredient performs.
a wide range of coating materials. The process is not as limiting as
Other processes that are used to produce encapsulated ingredi- spray drying.
ents are spray chilling and cooling. These two processes resemble
There are a number of other systems that may be used for encapspray drying during the initial steps. The ingredient manufacturer sulation, but their applications are more limited and some are simply
must select an encapsulating material, mix and homogenize ingredi- not appropriate for food systems. These include extrusion, lyophilizaent or flavor and the encapsulation material and then spray the mix- tion, centrifugal suspension separation, co-crystallization and interture into a chamber. The difference in the process is that in these facial polymerization. It is also possible to create an ingredient using
processes the goal is not to remove water to form the ingredient, but a combination of processes. Spray drying could be used to create a
to harden the encapsulating materials around the ingredient or flavor. product that has a hydrophilic or water-loving coating. This product
The encapsulating materials are not water, but fat soluble and are could then be processed in a fluidized bed system to coat it with a
typically fats, oils or derivatives.
fatty or lipophilic coating.
The difference between the two processes is the selection of the
44

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JANUARY 2004

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Meat + Poultry - January 2004

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