Method of encapsulating food or flavor particles using warm water fish gelatin, and capsules produced therefrom

This invention is directed to a method of forming microencapsulated food or flavor capsules as well as the capsules produced by the method. The method includes providing food or flavor particles to be encapsulated, and forming a mixture of a warm water fish gelatin and the food or flavor particles in aqueous media. The method further includes microencapsulating the particles with the gelatin at elevated temperatures by complex coacervation to form the microencapsulated capsules. If desired, the method may further include the step of separating the capsules. In a preferred form, the method is conducted at a temperature of about 33.degree. C. to about 35.degree. C. Preferably, the warm water fish gelatin used in the encapsulation method has a bloom of from about 150 to about 300 bloom, more preferably from about 250 to about 300 bloom. Many different kinds of food or flavor particles may be used, such as for example, vegetable oil, lemon oil, garlic flavor, apple flavor or black pepper. The invention also is directed to the food or flavor capsules produced by the method.

BACKGROUND OF THE INVENTION 
This invention relates to microencapsulation of food or flavor particles, 
and more particularly to microencapsulation of food or flavor particles by 
complex coacervation at elevated temperatures using a warm water fish 
gelatin. 
U.S. Pat. No. 5,035,896 to Apfel et al. teaches water insoluble drugs 
coated by simple coacervation using a low bloom fish gelatin which 
coacervates at ambient temperature, i.e., room temperature of about 
16.degree.-27.degree. C. However, the U.S. Pat. No. '896 patent does not 
disclose the use of fish gelatin in encapsulating other kinds of 
particles. Furthermore, the U.S. Pat. No. '896 coacervation process is 
limited to ambient or room temperature coacervation. 
SUMMARY OF THE INVENTION 
This invention is directed to a method of forming microencapsulated food or 
flavor capsules as well as the capsules produced by the method. The method 
includes providing food or flavor particles to be encapsulated, and 
forming a mixture of a warm water fish gelatin and the food or flavor 
particles in aqueous media. The method further includes microencapsulating 
the particles with the gelatin at elevated temperatures by complex 
coacervation to form the microencapsulated capsules. If desired, the 
method may further include the step of separating the capsules. 
In a preferred form, the method is conducted at a temperature of about 
33.degree. C. to about 35.degree. C. Preferably, the warm water fish 
gelatin used in the encapsulation method has a bloom of from about 150 to 
about 300 bloom, more preferably from about 250 to about 300 bloom. Many 
different kinds of food or flavor particles may be used, such as for 
example, vegetable oil, lemon oil, garlic flavor, apple flavor or black 
pepper. The invention also is directed to the food or flavor capsules 
produced by the method. 
This invention offers several benefits and advantages. For example, the 
method provides a way of encapsulating food or flavor particles using fish 
gelatin instead of other gelatin such as bovine or porcine gelatin. Also, 
the fish gelatin employed is a kosher fish gelatin; therefore, any kosher 
food or flavor particle will remain kosher upon encapsulation. In 
addition, the coacervation method is conducted at elevated temperatures, 
and does not require ambient/room temperature for coacervation.

DETAILED DESCRIPTION OF THE INVENTION 
The invention is directed to a method of forming microencapsulated food or 
flavor capsules, as well as to the capsules produced from the method. The 
method includes providing food or flavor particles to be encapsulated, and 
forming a mixture of a warm water fish gelatin and the food or flavor 
particles in an aqueous media. The method further includes 
microencapsulating the particles with the gelatin at elevated temperatures 
by complex coacervation to form the microencapsulated capsules. 
The warm water fish gelatin used in the method may be any warm water fish 
gelatin. However, in a preferred form of the invention, the fish gelatin 
has a bloom of from about 150 to about 300 bloom, and more preferably, a 
bloom of from about 250 to about 300 bloom. Such high bloom warm water 
fish gelatins are available from Food Industries Testing of Miami, Fla. 
under the product name Gelcine KFX. One of the advantages of using the 
fish gelatin is that it is kosher. Therefore, kosher food or flavor 
particles retain their kosher status upon encapsulation with the fish 
gelatin. 
As stated above, the method further includes microencapsulating the 
particles with the gelatin at elevated temperatures by complex 
coacervation. As used herein, "elevated temperatures" means temperatures 
above ambient or room temperatures, i.e., above 16.degree.-27.degree. C. 
During complex coacervation, a protein coating is formed over the food or 
flavor particles to produce microencapsulated capsules. The protein 
coating may then be cross linked by covalent or ionic bonding with a cross 
linking agent, and if desired, the capsules may be spray dried or 
otherwise dewatered at a suitable temperature for the removal of water. 
By employing the method of this invention, food or flavor particles in 
amounts of up to 95% by weight, typically within the range of about 50% to 
95% by weight, are encapsulated in a protein coating, i.e., at a ratio of 
about 10:1 to about 5:1 of particles to coating. Usually, about 70% to 
about 95% by weight particle encapsulation is achieved. In another feature 
of the invention, a drying aid is added to the coacervated emulsion of 
food or flavor particles before spray drying or dewatering. This drying 
aid has the effect of lubricating these spray dried, or otherwise 
dewatered particles and provides for uniform distribution of the 
particles. 
A variety of food or flavor particles may be encapsulated, such as for 
example, vegetable oil, lemon oil, garlic flavor, apple flavor or black 
pepper. Examples of other flavor oils include flavoring aromatic compounds 
and/or oils, oleoresins and extracts derived from plants, leaves, flowers, 
fruits and so forth, and combinations thereof. Flavor oils include 
cinnamon oil, oil of wintergreen, peppermint oil, bay oil, thyme oil, 
spearmint oil, cassia oil, and the like. Artificial, natural and synthetic 
fruit flavors such as vanilla, and citrus oils including lemon, orange, 
grapefruit, lime, and fruit essences including apple, pear, peach, 
strawberry, cherry, and so forth, may be used. These flavoring oils may be 
used individually or in a mixture as is well known in the art. 
The coating layer, as prepared by complex coacervation comprises colloidal 
materials which must be hydrophilic, gellable and ionizable. Colloidal 
materials may be selected from the group consisting of a warm water fish 
gelatin, alginates, casein, gum arabic, carboxymethylcellulose and the 
like, and mixtures thereof. 
Complex coacervation is practiced usually by first forming a solution of a 
first colloidal material, such as the warm water fish gelatin, in water 
above its gelation temperature. Separately, a second colloidal material, 
such as gum arabic or carboxymethylcellulose for example, is added to 
water to form a clear solution. The two solutions then are mixed, the 
temperature may be reduced, and the flavor oil is mixed into the resulting 
solution at a mixing speed to form the desired emulsion. Complex 
coacervation, or aggregation to uniformly distribute the colloidal 
materials around the food or flavor particles, then is carried out by 
diluting the emulsion with water, or adjusting the pH and allowing an 
elapsed time for the colloid to coat the particles. Then, in order to 
render the gelatin capsules insoluble, it is usually necessary to cross 
link the colloidal coating on the particles, and in a preferred form, 
glutaraldehyde is used to cross link the gelatin coating surrounding the 
particles. Alum also may be used to cross link the coated food or flavor 
particles. 
It is preferred to add a drying aid to the slurry of coated microcapsules 
in aqueous medium prior to spray-drying or dewatering. Silicon dioxide is 
a preferred drying agent having a particle size of less than 400 mesh, but 
the fineness of the drying agent is not critical. The coated flavor 
capsules are now ready for spray-drying and this may be accomplished by 
employing a spray-drying tower fitted with an air atomization nozzle for 
spraying countercurrent to the heated airflow. The coated food or flavor 
capsules are delivered to the spray nozzle by a pump at a suitable rate 
per hour. Atomization may be achieved in a number of ways. For example, 
air atomization, spinning disk or airless atomization may be employed. 
The resulting food or flavored capsules may be prepared in different forms, 
such as a liquid suspension or slurry (typically about 1% to about 40% by 
weight solids), a paste (about 36% to about 60% by weight solids), or a 
dry powder. The slurry form may have advantage in certain applications 
because of the benefits of particle cost savings, easy handling, and 
better particle containment because of reduced particle volatility in the 
water. The aqueous food or flavor capsules may be delivered by a pump at a 
suitable rate per hour in processing to afford easy handling. 
The following examples illustrate the practice of this invention. It will 
be understood, however, that these examples are not intended to limit the 
scope of the invention, which is to be determined by the appended claims 
and their equivalents. 
EXAMPLE 1 
Aqueous Capsules of Flavor Particles and Cross-Linked Warm Water Fish 
Gelatin Coating 
An aqueous suspension of vegetable oil microcapsules was produced according 
to the method of the invention. The warm water fish gelatin 300 bloom 
Gelcine KFX supplied by Food Industry Testing of Miami, Fla. was used to 
form 200 grams of a 10% fish gelatin solution at 33.degree. C. Then 100 
grams of a 4% CMC/ARABIC gum solution was prepared at room temperature. 
The gum and gelatin solutions were combined followed by the addition of 
160 grams of vegetable oil. 600 grams of dilution water at 35.degree. C. 
was added to the emulsion, and the resulting solution was cooled over a 
30-minute period to a temperature of about 25.degree. C. 2.5 grams of a 
50% aqueous solution of gluteraldehyde was added in order to cross link 
the gelatin. The result was an excellent aqueous suspension of 
microcapsules. In addition, a similar batch of capsules were prepared 
using the above steps, but substituting a 250 bloom warm water fish 
gelatin for the 300 bloom gelatin used above. 
Additional aqueous suspensions of microcapsules were prepared using lemon 
oil, garlic flavor or apple flavor instead of the vegetable oil discussed 
above. The method conducted using these particular flavors also resulted 
in an excellent aqueous suspension of microcapsules. 
EXAMPLE 2 
Spray-Dried, Free-Flowing Capsules of Flavor Particles And Cross-Linked 
Warm Water Fish Gelatin Coating 
The aqueous suspensions of lemon oil, garlic flavor and apple flavor 
capsules prepared in Example 1 above were further processed to form dry 
powders of flavor capsules. In order to form the dry powders, silicon 
dioxide was mixed into the slurries or aqueous suspensions to act as a 
drying aid upon spray-drying. The suspensions were then spray-dried using 
the spray-drying technique discussed above. This process resulted in dry, 
free flowing microcapsules.