Encapsulation of sensitive liquid components into a matrix to obtain discrete shelf-stable particles

Abstract

A liquid encapsulant component which contains an active, sensitive encapsulant, such as a live microorganism or an enzyme dissolved or dispersed in a liquid plasticizer is admixed with a plasticizable matrix material. The matrix material is plasticizable by the liquid plasticizer and the encapsulation of the active encapsulant is accomplished at a low temperature and under low shear conditions. The active component is encapsulated and/or embedded in the plasticizable matrix component or material. The liquid content of the liquid encapsulant component provides substantially all or completely all of the liquid plasticizer needed to plasticize the matrix component to obtain a formable, extrudable, cuttable, mixture or dough. Controlled release, discrete, solid particles which contain an encapsulated and/or embedded component such as a heat sensitive or readily oxidizable pharmaceutically, biologically, or nutritionally active component are continuously produced without substantial destruction of the matrix material or encapsulant.

1 . A method for encapsulating or embedding a component in a matrix comprising:
 a. obtaining a formable mixture by admixing ingredients comprising at least one plasticizable matrix material, a liquid encapsulant component, said liquid encapsulant component comprising an encapsulant and a liquid plasticizer, the amount of encapsulant being about 1% by weight to about 85% by weight, based upon the weight of the matrix material, and at least one component for controlling the rate of release of the encapsulant in an amount of about 5% to about 70% by weight, based upon the weight of the matrix material, wherein said plasticizable matrix material is plasticizable by said liquid plasticizer at a temperature which does not substantially destroy said encapsulant, said admixing being under low shear and low temperature conditions to plasticize the plasticizable material at a temperature of less than about 50° C. without substantially destroying the encapsulant to obtain a substantially homogeneous plasticized, viscoelastic, formable mixture, wherein the encapsulant is at least substantially uniformly distributed in the at least one plasticized matrix material,   b. forming said formable mixture into pieces, and   c. drying said pieces,   wherein said at least one plasticized matrix material is plasticized by a plasticizer selected from the group consisting of water, an aqueous-based composition, alcohol, glycerol, sorbitol, polyethylene glycol, polypropylene glycol, silicone, hexanol, pentanol, dimethylsulfoxide (DMSO), hexane, and mixtures thereof, and the amount of said at least one plasticized matrix material is at least about 30% by weight based upon the weight of said dry pieces.   
     
     
         2 . A method as claimed in  claim 1  wherein said liquid encapsulant component provides at least a substantial portion of the liquid plasticizer for forming said plasticized mixture. 
     
     
         3 . A method as claimed in  claim 2  wherein the liquid plasticizer content of said liquid encapsulant component is at least about 50% by weight, based upon the weight of said liquid encapsulant component. 
     
     
         4 . A method as claimed in  claim 2  wherein the liquid plasticizer content of said liquid encapsulant component is sufficient to form a substantially homogenous formable dough upon admixture of said liquid encapsulant component with said plasticizable matrix material. 
     
     
         5 . A method as claimed in  claim 4  wherein the liquid plasticizer content of said formable dough is from about 10% by weight to about 50% by weight, based upon the weight of the formable dough. 
     
     
         6 . A method as claimed in  claim 2  wherein liquid plasticizer in addition to the liquid plasticizer provided by said liquid encapsulant component is admixed with said plasticizable matrix material to obtain said formable mixture, the formable mixture is obtained in an extruder and extruded through a die without substantially expanding the formable mixture, and the extrudate is cut into pieces. 
     
     
         7 . A method as claimed in  claim 2  wherein the formable mixture is extruded to obtain an extrudate, the extrudate is cut into pieces, and the pieces are dried to a shelf-stable moisture content of less than about 10% by weight, based upon the weight of the pieces. 
     
     
         8 . A method as claimed in  claim 2  wherein said admixing to obtain said formable mixture is conducted at a pressure of from about 1 bar to about 100 bar. 
     
     
         9 . A method as claimed in  claim 2  wherein an additional encapsulant, in solid form, is admixed with said plasticizable matrix material. 
     
     
         10 . A method as claimed in  claim 9  wherein said additional encapsulant is coated with a film-forming material prior to admixing with said plasticizable matrix material. 
     
     
         11 . A method as claimed in  claim 2  wherein said formable mixture is obtained by admixing said ingredients in a continuous mixer to obtain a crumbly dough, feeding the crumbly dough to an extruder, and plasticizing the crumbly dough into a continuous, substantially homogeneous plasticized dough in said extruder, extruding the substantially homogeneous dough through an extruder die, and cutting the extrudate into individual pieces. 
     
     
         12 . A method as claimed in  claim 1  wherein said pieces are coated with a film-forming material. 
     
     
         13 . A method as claimed in  claim 2  wherein said plasticizable matrix material comprises either semolina or flour from cookies or crackers, and said liquid plasticizer comprises water. 
     
     
         14 . A method as claimed in  claim 13  wherein said liquid encapsulant component comprises at least one member selected from the group consisting of enzymes, vitamins, micronutrients, and live microorganisms. 
     
     
         15 . A method as claimed in  claim 2  wherein said at least one release-rate controlling component is a hydrophobic component. 
     
     
         16 . A method as claimed in  claim 15  wherein said hydrophobic component is at least one member selected from the group consisting of fats, oils, waxes, fatty acids, emulsifiers, polyolefins, polyurethanes, polyvinylchloride, paraffins, polyvinyl acetates, and modified starches. 
     
     
         17 . A method as claimed in  claim 2  wherein said at least one release-rate controlling component is a high water binding capacity component. 
     
     
         18 . A method as claimed in  claim 10  wherein said high water binding capacity component is selected from the group consisting of proteins, and hydrocolloids. 
     
     
         19 . A method as claimed in  claim 2  wherein the amount of said at least one release-rate controlling agent is from about 5% by weight to about 50% by weight, based upon the weight of said plasticizable matrix material. 
     
     
         20 . A method as claimed in  claim 13  wherein the semolina or cookie flour or cracker flour content of said pieces is at least about 40% by weight, based upon the weight of said dry pieces. 
     
     
         21 - 29 . (canceled) 
     
     
         30 . A method for encapsulating or embedding a component in a matrix comprising:
 a. obtaining a formable mixture by admixing ingredients comprising at least one plasticizable matrix material comprising a a plasticizable biopolymer, a liquid plasticizer, an encapsulant in an amount of about 1% by weight to about 85% by weight, based upon the weight of the matrix material, and an additional component selected from the group consisting of at least substantially non-gelatinized starch, carbohydrates which have a lower molecular weight than starches, fiber, cellulose, or hemi-cellulose for controlling the rate of release of the encapsulant, wherein said plasticizable matrix material is plasticizable by said liquid plasticizer at a temperature which does not substantially destroy said encapsulant, said admixing being under low shear and low temperature conditions to plasticize the plasticizable material at a temperature of less than about 50° C. without substantially destroying the encapsulant to obtain a substantially homogeneous plasticized, viscoelastic, formable mixture, wherein the encapsulant is at least substantially uniformly distributed in the at least one plasticized matrix material,   b. forming said formable mixture into pieces, and   c. drying said pieces,   wherein said at least one plasticized matrix material is plasticized by a plasticizer selected from the group consisting of water, an aqueous-based composition, alcohol, glycerol, sorbitol, polyethylene glycol, polypropylene glycol, silicone, hexanol, pentanol, dimethylsulfoxide (DMSO), hexane, and mixtures thereof, and the amount of said at least one plasticized matrix material is at least about 30% by weight based upon the weight of said dry pieces.   
     
     
         31 . A method as claimed in  claim 30  wherein said at least one additional component increases the penetrability or porosity of the matrix to permit quicker release of the encapsulant from the matrix. 
     
     
         32 . A method as claimed in  claim 30  wherein said at least one additional component comprises a sugar or a starch hydrolyzate. 
     
     
         33 . A method as claimed in  claim 30  wherein said at least one additional component comprises an at least substantially ungelatinized starch. 
     
     
         34 . A method as claimed in  claim 30  wherein said at least one plasticizable matrix material comprises a durum ingredient. 
     
     
         35 . A method as claimed in  claim 30  wherein a liquid encapsulant component which contains an active, sensitive encapsulant dissolved or dispersed in a liquid plasticizer is admixed with said at least one plasticizable matrix material. 
     
     
         36 . (canceled) 
     
     
         37 . A method as claimed in  claim 30  wherein an encapsulant in solid form is admixed with said plasticizable matrix material. 
     
     
         38 . A method as claimed in  claim 30  wherein said encapsulant is coated with a film-forming material prior to admixing with said plasticizable matrix material. 
     
     
         39 . A method as claimed in  claim 30  wherein said encapsulant comprises at least one member selected from the group consisting of enzymes, vitamins, micronutrients, and live microorganisms. 
     
     
         40 . A method as claimed in  claim 30  wherein an oil or fat is admixed with said plasticizable matrix material for controlling the rate of release of said encapsulant from the matrix. 
     
     
         41 . A method for encapsulating or embedding a component in a matrix comprising:
 a. obtaining a formable mixture by admixing ingredients comprising at least one plasticizable matrix material comprising a plasticizable biopolymer, a liquid plasticizer, an encapsulant in an amount of about 1% by weight to about 85% by weight, based upon the weight of the matrix material, a matrix component which is substantially non-plasticizable at temperatures lower than the decomposition temperature of the encapsulant, and at least one component for controlling the rate of release of the encapsulant, wherein said plasticizable matrix material is plasticizable by said liquid plasticizer at a temperature which does not substantially destroy said encapsulant, said admixing being under low shear and low temperature conditions to plasticize the plasticizable material at a temperature of less than about 50° C. without substantially destroying the encapsulant to obtain a substantially homogeneous plasticized, viscoelastic, formable mixture, wherein the encapsulant is at least substantially uniformly distributed in the at least one plasticized matrix material,   b. forming said formable mixture into pieces, and   c. drying said pieces,   wherein said at least one plasticized matrix material is plasticized by a plasticizer selected from the group consisting of water, an aqueous-based composition, alcohol, glycerol, sorbitol, polyethylene glycol, polypropylene glycol, silicone, hexanol, pentanol, dimethylsulfoxide (DMSO), hexane, and mixtures thereof, and the amount of said at least one plasticized matrix material is at least about 30% by weight based upon the weight of said dry pieces.   
     
     
         42 . A method as claimed in  claim 41  wherein the substantially non-plasticizable matrix component is selected from the group consisting of at least substantially non-gelatinized starch, carbohydrates which have a lower molecular weight than starches, fiber, cellulose, and hemi-cellulose. 
     
     
         43 . A method as claimed in  claim 41  wherein the substantially non-plasticizable matrix component comprises an at least substantially non-gelatinized starch, said plasticizable matrix material comprises semolina, and said at least one component for controlling the rate of release of the encapsulant comprises a fat or oil. 
     
     
         44 . A method as claimed in  claim 41  wherein a liquid encapsulant component which contains said encapsulant dissolved or dispersed in said liquid plasticizer is admixed with said at least one plasticizable matrix material. 
     
     
         45 . A method as claimed in  claim 44  wherein said encapsulant component comprises at least one member selected from the group consisting of enzymes, vitamins, micronutrients, and live microorganisms. 
     
     
         46 - 67 . (canceled) 
     
     
         68 . A method according to  claim 41 , wherein the substantially non-plasticizable matrix component comprises a member selected from the group consisting of an at least substantially non-gelatinized starch, fiber, cellulose and hemi-cellulose. 
     
     
         69 . A method as claimed in  claim 41  wherein the liquid plasticizer content of said formable mixture is from about 10% by weight to about 50% by weight, based upon the weight of the formable mixture. 
     
     
         70 . A method as claimed in  claim 1  wherein the formable mixture is extruded through a die having multiple apertures, at a rate of extrudate per die area of less than about 5 kg/h per mm 2 . 
     
     
         71 . A method as claimed in  claim 70 , wherein the rate of extrudate per die area is less than 3 kg/h per mm 2 . 
     
     
         72 . A method as claimed in  claim 71 , wherein the rate of extrudate per die area is less than about 0.5 kg/h per mm 2 . 
     
     
         73 . A method as claimed in  claim 70 , wherein the diameter of the apertures is from about 0.3 mm to about 5 mm. 
     
     
         74 . A method as claimed in  claim 73 , wherein the diameter of the apertures is from about 0.5 mm to about 1 mm. 
     
     
         75 - 85 . (canceled) 
     
     
         86 . A method as claimed in  claim 1 , wherein said liquid encapsulant component comprises at least one enzyme. 
     
     
         87 . (canceled) 
     
     
         88 . A method as claimed in  claim 1  wherein said plasticizable matrix material which is admixed with said liquid encapsulant component is in solid form. 
     
     
         89 . A method as claimed in  claim 1  wherein said at least one plasticizable matrix material comprises at least one member selected from the group consisting of high gluten content flours, gluten from wheat, durum wheat, and durum semolina. 
     
     
         90 - 91 . (canceled) 
     
     
         92 . A method as claimed in  claim 41 , wherein the substantially non-plasticizable matrix component comprises an at least substantially non-gelatinized starch. 
     
     
         93 . A method as claimed in  claim 41  wherein said at least one plasticizable matrix material comprises at least one member selected from the group consisting of high gluten content flours, gluten from wheat, durum wheat, and durum semolina. 
     
     
         94 . A method as claimed in  claim 41  wherein said at least one component for controlling the rate of release of the encapsulant comprises a protein. 
     
     
         95 . A method as claimed in  claim 41  wherein the pieces obtained by said drying are hardened, solidified, discrete particles and may be ground. 
     
     
         96 - 115 . (canceled) 
     
     
         116 . An encapsulated product comprising a substantially homogeneous mixture of:
 at least one plasticized matrix material comprising a plasticized biopolymer in an amount of at least about 30% by weight, based upon the weight of the encapsulated product, said plasticized biopolymer being plasticized at a temperature of less than about 50° C., and   about 1% by weight to about 85% by weight of an encapsulant, based upon the weight of the matrix material, wherein the encapsulant is at least substantially uniformly distributed in said at least one plasticized matrix material, said encapsulant being at least one member selected from the group consisting of essential unsaturated fatty acids, highly unsaturated fatty acids, omega-3 fatty acids, mid-chain triglycerides, flavorants, detergents, and surface active components.   wherein said at least one plasticized matrix material is plasticized by a plasticizer selected from the group consisting of water, an aqueous-based composition, alcohol, glycerol, sorbitol, polyethylene glycol, polypropylene glycol, silicone, hexanol, pentanol, dimethylsulfoxide (DMSO), hexane, and mixtures thereof, and said encapsulated product is in substantially non-expanded, particulate form.   
     
     
         117 - 118 . (canceled) 
     
     
         119 . An encapsulated product as claimed in  claim 116  wherein said at least one plasticized matrix material comprises at least one member selected from the group consisting of a durum ingredient, a pregelatinized starch, and a modified starch. 
     
     
         120 - 133 . (canceled) 
     
     
         134 . An encapsulated product as claimed in  claim 116  further comprising at least one component for controlling the rate of release of the encapsulant. 
     
     
         135 . An encapsulated product as claimed in  claim 134  wherein said at least one release-rate controlling component is a hydrophobic agent for controlling the rate of release of the encapsulant. 
     
     
         136 . An encapsulated product as claimed in  claim 134  wherein said at least one release-rate controlling component is a high water binding capacity component for controlling the rate of release of the encapsulant. 
     
     
         137 . An encapsulated product as claimed in  claim 134  wherein the amount of said at least one release-rate controlling component is about 5% to about 70% by weight, based upon the weight of the at least one plasticizable matrix material. 
     
     
         138 - 148 . (canceled)