Title:  Sensitive substance encapsulation

United States Patent:  6,251,478

Assignee:  Balchem Corporation (Slate Hill, NY)

Filed:  December 22, 1999

A process for stabilizing a sensitive substance; (a) plating a sensitive substance onto a solid carrier under a controlled atmosphere to reduce loss of the sensitive substance; (b) encapsulating the plated material under controlled atmosphere and airflow to reduce volatilization during the process and stabilize the sensitive substance.

DETAILED DESCRIPTION OF THE INVENTION

A sensitive substance such as a volatile liquid material is first plated onto a solid carrier in a sealed reactor. The reactor is then filled with nirogen, carbon dioxide, or any other suitable gas inert to the sensitive substance to displace any unconditioned air. Then the plated material is encapsulated either in the same vessel in which the plating occurred or in another vessel.

The carrier is placed in a vessel capable of being sealed and supporting mechanical mixing. Preferably the mechanical mixing creates a fluidized bed. The vessel is then sealed and then oxygen is displaced through the introduction of an inert gas. Suitable gases include, but are not limited to, carbon dioxide, nitrogen, and helium. The inert gas also acts as a blanket. The inert gas is selected so that it will not react with the volatile material or the carrier. The carrier material is then agitated.

A liquid material (oxygen sensitive liquid material) is then agitated to ensure a fully homogenized mire. Without exposing the liquid material to air or oxygen, the liquid material is then supplied, e.g. pumped, into the sealed vessel and introduced into the vessel by a nozzle. The nozzle is used to form small droplets that are more easily absorbed onto the carrier material. The time involved in spraying is dependent upon the addition level of the liquid onto the solid and the time required to ensure complete absorption to form a free flowing powder. While the volatile liquid material is being added, the carrier is agitated or nixed to ensure even distribution of the liquid material onto the solid carrier.

A typical volatile liquid material has a boiling point between about 40^oF. and about 250^oF., preferably about 50^o to about 100^oF., and more preferably about 60^o to about 80^oF. Examples of volatile materials also include, but are not limited to, flavors, flavor compounds, aromas, fragrances, vitamins, nutrients (such as omega 3 oils, carotenoids, vitamin A and E), alcohols, acetones, ketones, aldehydes, organic acids, antioxidants, and essential oils. Examples of volatile materials are: lemon oil, spearmint oil, vanilla extract, garlic oil, cinnamon extract and other essential oils derived from botanical origins.

Other sensitive materials include biologically active compounds which include, but are not limited to, Lactobacilli, Bifidobacterium, Enterococci, phytase, amylases, lipases, invertases, transglutaminases, proteases, lipoxygenases and pentosanases.

The carrier may be any porous or semi porous material such as, but not limited to, maltodextrin, dextrins silicon dioxide, starches, gums or hydrocolloids. The carrier is selected based upon its ability to entrap the liquid material. Suitable carriers include, but are not limited to, the following. N-ZORBIT M which is a tapioca maltodextrin derived from tapioca and K-4484 which is a tapioca dextrin with high solubility, good clarity, and bland flavoring. N-ZORBIT M and K-4484 are products of National Starch and Chemical Company.

The particle size of the carrier is preferably between about 50 microns and about 2,000 microns, preferably between about 100 microns and about 1000 microns, and more preferably between about 200 and about 500 microns. Both the volatile liquid material and solid carrier may be edible.

Loading levels of the liquid onto the solid carrier are between about 1% and about 70% by weight, preferably 5% to 40%, more preferably between about 10% and about 30%, and most preferably between about 15% and about 25%. One skilled in the art would understand the amount of volatile material needed for a particular end product. For example, garlic is very strong and thus would require a lower loading concentration as would cinnamon. Apple juice would likely require a higher concentration.

Prior to adding the liquid material, the carrier may be chilled by, for example, the addition of liquid nitrogen which has a temperature between minus 198^o and minus 208^oC. The liquid material may also be chilled to below about 40^o F., and kept chilled while it is added to the carrier. If desired, the vessel may also have a cooling jacket to cool the vessel during the plating process.

Any suitable mixer vessel, such as a paddle mixer, ribbon blender, or V-blender, may be used in the present invention to plate the solid onto the carrier.

After the volatile liquid material is plated onto a solid carrier to form a plated material, the plated material is encapsulated either in the same vessel in which the plating occurred or in another vessel. In a preferred embodiment, the plated material is removed from the sealed mixer and placed in a reactor designed to encapsulate solid particles. In either case, the encapsulation reactor must be capable of being sealed. The reactor is then filled with nitrogen, carbon dioxide, or any other suitable gas inert to the volatile material to displace any unconditioned air. Preferably, the vessel has means to agitate and heat the contents of the vessel.

Any suitable encapsulant material may be used. Preferably the encapsulating material is a lipid material such as, but not limited to, mono-, di-, and triacylglycerols, waxes, and organic esters derived from animals, vegetables, minerals, and modifications. Examples include glyceryl triesterates such as soybean oil, cotton seed oil, canola oil, tallow and palm kernal oil, and esters of long chain fatty acids, and alcohols, such as carnauba wax, beeswax, bran wax, tallow and palm kernal oil. The lipid material preferably has a melting point between about 60^o and about 200^o F.

Specific encapsulants include, but are not limited to, the following. NATIONAL 46 which is a low viscosity product designed for the encapsulation of citrus flavors, such as orange and lemon, and other delicate flavor oils. CAPSUL which is a modified food starch derived from waxy maize designed for encapsulation of flavors, clouds, vitamins, and spices. N-LOK which is a low viscosity product designed for the encapsulation of flavors, fats, oils, and vitamins. NATIONAL, CAPSUL, and N-LOK are all products of National Starch and Chemical Company.

In a preferred embodiment, the encapsulant material is melted and the liquefied material is then pumped into the encapsulation reactor. The flow rate is dependent upon the type of encapsulation reactor used in the procedure and is well within the skill of the art. The carrier containing volatile material is fluidized in the reactor by methods known to those who are skilled in the art such as by forcing an inert gas upward through a bed of particles so that the particles undergo a continuous circular, tumbling action. As the particles are fluidized, the liquefied material is sprayed onto the fluidized particles.

The final percentage of encapsulant (coating) in the resulting encapsulated particles is between about 10 to about 90%, preferably about 20 to about 80% and more preferably between about 30 and about 50% by weight.

Claim 1 of 20 Claims

What is claimed is:

1. A method of encapsulating a sensitive material comprising:

plating the sensitive material onto a solid carrier, in an atmosphere inert to the sensitive material, to form a plated material; and

encapsulating the plated material.

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