PRESERVATIVE-FREE FREEZED-DRIED FOODS AND METHODS OF MAKING THE SAME

Abstract

The present invention relates to novel freeze-dried confection compositions, and methods for making the same. There is a long-felt need for nutritious snacks that are preserved for long periods without preservatives and having acceptable flavor. The freeze-dried confections of the present invention comprise are composed of freeze-dried raw fruits and vegetables and other natural ingredients with no preservatives, and prepared in such a way that they can be preserved at room temperature for many years.

Claims

1. A method of providing a preserved food product with no added preservative chemicals comprising the steps of: a. providing a pureed food ingredient free from preservative chemicals; b. admixing a non-oxidizing gas with the pureed food ingredient; c. thermally processing the pureed food ingredient; and d. freeze drying the food ingredient.

2. The method of claim 1 wherein the food ingredient is present in an amount of greater than 95% wt/wt of the product.

3. The method of claim 1, wherein the food product comprises at least one fresh fruit or vegetable.

4. The method of claim 1, wherein the food product includes a baked food mixture free from preservative chemicals.

5. The method of claim 1, wherein the non-oxidizing gas comprises nitrogen gas.

6. The method of claim 1, wherein the pureed food ingredient is shaped into a pre-determined shape.

7. The method of claim 6, wherein the pureed food ingredient is poured in to a mold prior to the step of thermally processing the blend.

8. The method of claim 6, wherein the pre-determined shape has a volume of less than about five cubic inches.

9. The method of claim 1, further comprising mixing plant extract into said pureed food ingredient, wherein said emulsifier is added into said pureed food ingredient at a concentration of 0.01% wt/wt to about 5% wt/wt of the pureed food ingredient.

10. The method of claim 9, further comprising mixing at least one emulsifier into said pureed food ingredient, wherein said emulsifier is added into said pureed food ingredient at a concentration of 0.001% wt/wt to about 1% wt/wt of the pureed food ingredient.

11. The method of claim 1, further comprising displacing air from said pureed food ingredient.

12. The method of claim 1, further comprising displacing O.sub.2 from said pureed food ingredient.

13. The method of claim 1, further comprising pouring said pureed food ingredient into a mold having a volume of less than about 4 cubic inches.

14. The method of claim 1, further comprising pulverizing the freeze-dried pureed food ingredient.

15. The method of claim 14, further comprising said freeze-dried food ingredient into a mold having a volume of less than about 1 cubic inch.

16. A shelf stable freeze-dried food product comprising at least 90% wt/wt fresh fruit or vegetable ingredient that is free from preservative chemicals and that comprises is substantially water-free and oxygen-free.

17. The product of claim 16, wherein the food ingredient is present in an amount of greater than 95% wt/wt of the product.

18. The product of claim 16, further comprising a non-oxidizing gas.

19. The product of claim 16, wherein the non-oxidizing gas is nitrogen gas.

20. The product of claim 16, wherein the pureed food ingredient is shaped into a pre-determined shape.

21. The product of claim 20, wherein the fresh fruit is pureed food ingredient is pureed and poured in to a mold to form said pre-determined shape.

22. The product of claim 16, wherein the pre-determined shape has a volume of less than about five cubic inches.

23. The product of claim 16, further comprising mixing plant extract into said pureed food ingredient, wherein said emulsifier is added into said pureed food ingredient at a concentration of 0.01% wt/wt to about 5% wt/wt of the pureed food ingredient.

24. The product of claim 16, further comprising mixing at least one emulsifier into said pureed food ingredient, wherein said emulsifier is added into said pureed food ingredient at a concentration of 0.001% wt/wt to about 1% wt/wt of the pureed food ingredient.

25. The product of claim 20, wherein said pre-determined shape is formed by pulverizing a freeze-dried food ingredient into a fine powder, and placed in a press.

26. The product of claim 25, wherein said pre-determined shape has a volume of less than about 1 cubic inch.

27. A shelf stable freeze-dried food product comprising a food product free from preservative chemicals and that comprises is substantially water-free and oxygen-free.

28. The product of claim 27, wherein the food ingredient is present in an amount of greater than 95% wt/wt of the product.

29. The product of claim 28, wherein the food ingredient comprises at least one fresh fruit or vegetable.

30. The product of claim 28, wherein the food ingredient consists of at least one type of fresh fruit or vegetable.

31. The product of claim 28, wherein the food ingredient includes a baked food mixture free from preservative chemicals.

32. The product of claim 27, further comprising a non-oxidizing gas.

33. The product of claim 27, wherein the non-oxidizing gas is nitrogen gas.

34. The product of claim 27, wherein the pureed food ingredient is shaped into a pre-determined shape.

35. The product of claim 34, wherein the fresh fruit is pureed food ingredient is pureed and poured in to a mold to form said pre-determined shape.

36. The product of claim 27, wherein the pre-determined shape has a volume of less than about five cubic inches.

37. The product of claim 27, further comprising an emulsifier.

38. The product of claim 37, wherein said emulsifier is present in a concentration of 0.001% wt/wt to about 1% wt/wt of the freeze-dried product.

39. The product of claim 34, wherein said pre-determined shape is formed by pulverizing a freeze-dried food ingredient into a fine powder, and placed in a press.

40. The product of claim 27, wherein said pre-determined shape has a volume of less than about 1 cubic inch.

41. A freeze-dried product comprising a blend selected from the group consisting of fruit, vegetable, dairy, protein, grain and combinations thereof in an amount of greater than about 95% of the freeze-dried product, said freeze-dried product being substantially free from water and oxygen gas.

42. The product of claim 41, wherein the blend is present in an amount of greater than 95% wt/wt of the product.

43. The product of claim 42, wherein the food ingredient comprises at least one fresh fruit or vegetable.

44. The product of claim 42, wherein the food ingredient consists of at least one type of fresh fruit or vegetable.

45. The product of claim 42, wherein the food ingredient includes a baked food mixture free from preservative chemicals.

46. The product of claim 41, further comprising a non-oxidizing gas.

47. The product of claim 41, wherein the non-oxidizing gas is nitrogen gas.

48. The product of claim 41, wherein the pureed food ingredient is shaped into a pre-determined shape.

49. The product of claim 48, wherein the fresh fruit is pureed food ingredient is pureed and poured in to a mold to form said pre-determined shape.

50. The product of claim 41, wherein the pre-determined shape has a volume of less than about five cubic inches.

51. The product of claim 41, further comprising mixing plant extract into said pureed food ingredient, wherein said emulsifier is added into said pureed food ingredient at a concentration of 0.01% wt/wt to about 5% wt/wt of the pureed food ingredient.

52. The product of claim 41, further comprising mixing at least one emulsifier into said pureed food ingredient, wherein said emulsifier is added into said pureed food ingredient at a concentration of 0.001% wt/wt to about 1% wt/wt of the pureed food ingredient.

53. The product of claim 48, wherein said pre-determined shape is formed by pulverizing a freeze-dried food ingredient into a fine powder, and placed in a press.

54. The product of claim 41, wherein said pre-determined shape has a volume of less than about ¼ cubic inches.

55. A method of providing a preserved food product with no added preservative chemicals comprising the steps of: a. creating a blended food product comprising greater than 95% wt/wt of a pureed food ingredient free from preservative chemicals; b. admixing a non-oxidizing gas with the pureed food ingredient to displace O.sub.2 from the blended food product; c. placing the blended food product in a mold having a pre-determined shape; d. thermally processing the pureed food ingredient; and e. freeze drying the food ingredient.

56. The method of claim 55, wherein the pureed food product comprises at least one fresh fruit or vegetable.

57. The method of claim 55, wherein the pureed food product includes a baked food mixture free from preservative chemicals.

58. The method of claim 55, wherein the non-oxidizing gas comprises nitrogen gas.

59. The method of claim 55, wherein the pre-determined shape has a volume of less than about five cubic inches.

60. The method of claim 55, further comprising mixing plant extract into said pureed food ingredient, wherein said emulsifier is added into said pureed food ingredient at a concentration of 0.01% wt/wt to about 5% wt/wt of the pureed food ingredient.

61. The method of claim 55, further comprising mixing at least one emulsifier into said pureed food ingredient, wherein said emulsifier is added into said pureed food ingredient at a concentration of 0.001% wt/wt to about 1% wt/wt of the pureed food ingredient.

62. The method of claim 55, further comprising pulverizing the freeze-dried pureed food ingredient.

63. The method of claim 62, further comprising said freeze-dried food ingredient into a mold having a volume of less than about 1 cubic inch.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0030] FIG. 1A shows a flow chart of a process for processing a food starting material into a freeze-dried product according to a method of the present invention.

[0031] FIG. 1B shows a flow chart of a process for processing a freeze-dried food product to yield a compress snack or candy according to a method of the present invention.

[0032] FIG. 2 shows an freeze-drying apparatus according to an embodiment of the present invention.

DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

[0033] Reference will now be made in detail to certain embodiments of the invention, examples of which are illustrated in the accompanying drawings. While the invention will be described in reference to these embodiments, it will be understood that they are not intended to limit the invention. Conversely, the invention is intended to cover alternatives, modifications, and equivalents that are included within the scope of the invention as defined by the claims. In the following disclosure, specific details are given as a way to provide a thorough understanding of the invention. However, it will be apparent to one skilled in the art that the present invention may be practiced without these specific details. Referring to the drawings, wherein like reference characters designate like or corresponding parts throughout the several views, and referring particularly to FIGS. 1-2, it is seen that the present invention includes various embodiments of freeze-dried food products and methods of making the same.

[0034] As shown in FIG. 1, the present invention includes a method of preparing a freeze-dried product that may comprise the steps of (1) providing a puree or other mixture of fresh fruit, fresh vegetable, and/or other foods, (2) adding a plant extract and/or an emulsifier and blending the mixture (3) admixing a non-oxidizing gas with the blend to reduce the density of the composition and displace O.sub.2 and other air components, (4) applying a pre-determined shape to food product prior to thermally processing the mixture, (5) thermally processing (e.g., freezing) the mixture, (6) applying a primary freeze-drying process, and (7) applying a secondary freeze-drying process. This process removes water, liquids, and oxidants from the from the freeze-dried food that eliminates chemical, biochemical, and microbiological processes that would otherwise breakdown and spoil the food. The freeze-drying process allows for preservation of the novel snack foods without preservatives.

[0035] A starting material 101 containing fresh fruit and/or vegetable content, or other food material (e.g., ice creams and baked goods) with no added preservative chemicals may be used for composing the freeze-dried food product. The starting material may be blended or pureed in an electric blender to provide a uniform consistency to the starting material. In step 2, the starting material may be mixed with one or more natural plant extracts 102 free from added preservative chemicals. The one or more plant extracts may be ingestible and may have medicinal and/or nutritional value when ingested. The plant extracts may include one or more of citrus extracts (e.g., lemon oil, orange oil, grape fruit oil, etc.), sesame oil, cinnamon oil, clove oil, geranium oil, lemongrass oil, mint oil, spearmint oil, wintergreen oil, rosemary oil, anise oil, fennel oil, ginger oil, chamomile oil, coriander oil, cumin oil, dill oil, parsley oil, basil oil, eucalyptus oil, jasmine oil, yarrow oil, ginger oil, bergamot oil, oregano oil, lavender oil, pepper oil, rose oil, tea tree oil, tea seed oil, turmeric oil, thyme oil, garlic oil, peppermint oil, onion oil, and cannabidiol oil, and others plant extracts having analgesic, medicinal and/or nutritional properties. The one or more plant extracts may be present in an amount of from about 0.001% wt/wt to about 20% wt/wt, preferably from about 0.01% wt/wt to about 10% wt/wt, of the food product composition.

[0036] Step 2 may also include the addition of one or more emulsifiers 103 to the mixture, which may reduce the surface tension at the air-liquid interface, therefore allowing for stable dispersion of non-oxidizing gas and the one or more plant extracts within the viscous liquid matrix of the pureed starting material. Thus, the emulsifier aids in the infusion of non-oxidizing gas into and the displacement of air into the puree, as the gas is able to more readily cross the penetrate or escape the puree due to the reduced surface tension. The emulsifier also aids in the miscibility and even dispersion of hydrophobic compounds in the one or more plant extracts throughout the puree. The one or more emulsifiers 103 may include lecithin, mono- and diglycerides fatty acids and their esters with acetic, citric, lactic, and mono- and diacetyl tartaric or tartaric acids, distilled monoglycerides, polyglycerol fatty acid esters; polyoxyethylene sorbitan fatty acid esters (polysorbates); propylene glycol fatty acid esters; sorbitan fatty acid esters; stearoyl-2-lactylate salts; sugar esters; ammonium phosphatide, fatty acid salts, glycerol esters of wood resin, quillaia extract, and thermally oxidized soybean oil interacted with mono- and diglycerides of fatty acids are other approved emulsifiers. The one or more emulsifiers 103 may be present in an amount of from about 0.001% wt/wt to about 1% wt/wt, preferably from about 0.01% wt/wt to about 0.5% wt/wt, of the composition.

[0037] In step 3, the mixture may be treated with a non-oxidizing gas prior to the freezing stage in order to displace the air, and particularly the gaseous oxygen therein to prevent oxidation of the food product. This step may be performed in pressure chamber 104 with the mixture of the puree, plant extract, and/or emulsifier placed in the pressure chamber 104, and nitrogen gas may be pumped into the pressurized chamber 104, thereby displacing the air (including O.sub.2). The displaced air may be released from the pressurized chamber via a valve. A sufficient amount of N.sub.2 gas may be pumped into the chamber 104 to infuse the puree and displace substantially all of the air in the puree (e.g., in a range of about 80% to about 99% of the air volume present in the puree). The blender chamber may include a hose attachment for passing N.sub.2 gas pumped from a reservoir 105. The chamber 104 may also include a one-way valve to allow the air to be vented from the blender chamber.

[0038] In step 4, the pureed mixture may be molded into pre-determined shapes. The puree may be molded into a geometric body of a regular shape, for example, in particular, spherical caps, spheroidal caps, rectangular prisms, pyramids, as well as irregular shapes and whimsical shapes, such as those in the form of animals, plants and parts of plants, such as leaves etc. by a mold structure 106. In step 5, the mold structure may then be placed in a thermal treatment unit 107, which may be a conventional freezer, a blast freezer, or other thermal treatment unit. The rate at which a material is frozen during the thermal processing is dependent on the type of material. Higher water content of pureed fruits and vegetables correlates with a higher freezing rate. Fruits and vegetable purees may have a moisture content in a range of about 80% wt/wt to about 95% wt/wt. Such materials may be best frozen at a relative low temperature in order to yield a higher number of small ice crystals, which facilitates sublimation of the ice during the drying process. The freezing temperature for such fruit and vegetable purees may be in the range of about −50° C. to about −20° C. (or any value or range of values therein).

[0039] In step 6, the thermally processed mixture may undergo a primary freeze-drying process, in which the ice sublimation occurs. The thermally-processed, molded mixture may be placed in a freeze-drying apparatus 108 (a more detailed depiction of a freeze-drying apparatus is provided in FIG. 2). The thermally-processed, molded mixture may be placed on shelves 108a, from which heat may be transferred from the shelf to the surface of the frozen composition and heating the frozen water. Heating elements 108b may warm the shelf, which may then transfer the thermal energy to the mixture thereon. The pressure, vapor pressure, and applied heat parameters during the freeze-drying process are pre-determined to accomplish successful freeze-drying. The supplied heat may be fluctuated depending on the heating method: for contact heating using a heating shelf arrangement, the shelf temperature determines heat transfer. The temperature of the condenser surface should be from about 10° C. to about 20° C., depending on the type of freeze-dried material. The pressure within the chamber may be in a range of about 0.001 atm to about 0.01 atm. Sublimed steam may be removed from the freeze-drying chamber by applied vacuum. The vapor extracted from the food product may be removed from the drying chamber by means of condenser plates or coils of condenser chamber wherein the vapor can be re-solidified or frozen.

[0040] In step 7, a secondary drying step (a post-drying step) may be conducted under a reduced pressure to remove unfrozen water and/or other liquids that cannot be removed by sublimation. This step may be performed to remove the water present in the freeze-dried material that did not form ice during the freezing process, and instead is bound to the solid material (matrix) of the freeze-dried substance. During the second drying step, the freeze-dried food product may go through a second freeze-drying process in the freeze-drying apparatus 108 to desorb absorbed water (water attached to the dry material that did no freeze) by evaporation and desorption of the formed steam from the solid matrix of the freeze-dried product, convective transport through pores in the material, gas diffusion of the steam, and diffusion of water out of the matrix and dry material. During this phase the shelf temperature is further increased up to a maximum of about 20° C. to about 40° C. to heat the product, while the pressure inside the drying chamber is lowered to below about 0.0001 atm to about 0.001 atm. At the end of secondary drying phase, the product may be sufficiently dried with residual moisture content typically of about 1% to about 3% wt/wt.

[0041] In some embodiments, the methods of the present invention may include additional steps to create a compressed-form confection from the freeze-dried food product. As shown in FIG. 1B, the method of the present invention may include the additional steps 8 and 9: powderizing the freeze-dried product and pressing the powderized food product into a compressed form. The powderization and compression may provide uniform texture and/or to allow for quick dissolution of the freeze-dried food product when ingested. In step 8, the freeze-dried food product 110 can be powderized using a grinder or mill 150 to break down the food product 110 into a fine powder. In some embodiments, this may be performed in a low-oxygen environment, under N.sub.2 gas provided by a reservoir 155 to prevent the additional of oxygen species into the freeze-dried material. The powderized food product may have a particle diameter of about 50 μm to about 250 μm (e.g., about 100 μm to about 200 μm, or any range or value therein).

[0042] In step 9, the powderized food product may then be placed into a mechanical press 160 to form compact bite-sized snack/candies 115 of uniform size and density to allow for the product to be easily packaged into various packaging types, including small pouches, candy trays and tins, plastic tubes, candy and roll packaging. The press 160 may form a bite-sized snack or candy 115 by pressing action of two sets of punches (upper punches 161 and lower punches 162) and a die 165. In a first step, a lower punch 162 may be raised into a cavity in the die 165 creating a cavity into which the powderized food product is fed through the feeding delivery system 164. The depth of the lower punch 162 may be set to apply a pre-determined size and volume of the snack or candy 115. An upper punch 161 may be brought into contact with the powder and compress the powderized food product to fuse the powderized food product together into a hard snack or candy 115. After compression, the lower punch 162 may be raised to remove the snack or candy 115. The upper punches 161 may be on a track, belt, or chain 161a and may be inferiorly actuated by compression rollers 166a and 166b. The lower punches 162 may be on a track, belt, or chain 162a and may be inferiorly actuated by compression rollers 167a and 167b. The pressing process may provide a consistently sized and shaped confection product.

[0043] The freeze dryer apparatus 200 may have a drying chamber 201, an external condenser 202, and a vacuum pump system 203 for reducing pressure in the chamber. The vacuum pump system may be operable to reduce the pressure in the drying chamber 201 during the primary and secondary freeze-drying processes (e.g., to a pressure of about 0.0001 atm or greater). Sublimation begins at the outer surface of the specimen and recedes towards the center of the specimen as drying advances. The sublimation of frozen water and/or other liquids creates dried regions with porous structure, comprising a network of pores and gaps for the vapor escape. As ice molecules change to a vapor state, they are carried away from the specimen by lower pressure in the drying chamber. The condenser 201 collects the moisture removed from the food product mixture warmed to a relatively higher temperature by the radiant heat sources 108b and the shelves 108a in the low-pressure freeze-drying environment. The refrigerated condenser has a lower local temperature and presents substantially lower vapor pressure than in the drying chamber, which causes a migration of the vapor from the drying chamber to the condenser 202 region.

CONCLUSION/SUMMARY

[0044] The present invention provides novel freeze-dried food products (e.g., confections) and methods of making the same. It is to be understood that variations, modifications, and permutations of embodiments of the present invention, and uses thereof, may be made without departing from the scope of the invention. It is also to be understood that the present invention is not limited by the specific embodiments, descriptions, or illustrations or combinations of either components or steps disclosed herein. The embodiments were chosen and described in order to best explain the principles of the invention and its practical application, to thereby enable others skilled in the art to best utilize the invention and various embodiments with various modifications as are suited to the particular use contemplated. Although reference has been made to the accompanying figures, it is to be appreciated that these figures are exemplary and are not meant to limit the scope of the invention. It is intended that the scope of the invention be defined by the claims appended hereto and their equivalents.