Abstract: A process for making a shelf-stable food, not requiring preservatives or refrigeration and in a form that is convenient for use as a snack food. A block of tofu or wheat gluten is first frozen so as to cause the formation of ice crystals that form cavities within the block. The frozen block is then thawed, cut into smaller pieces and drained of excess water. The thawed pieces are dried in a microwave-vacuum dehydrator to produce a crunchy food product.

Abstract: A method and apparatus for pasteurizing and drying cannabis plant materials using a microwave-vacuum chamber. The pasteurizing and drying are carried out with no use of ionizing radiation and with rapid drying. Pasteurization is done at a temperature and for a time period that are sufficient to reduce microorganisms to an acceptably low level, while not significantly reducing the psychoactive compounds in the material. In the process, the pressure inside a vacuum chamber is reduced to a first pressure less than atmospheric. The material is maintained in the vacuum chamber at the first pressure at a pasteurizing temperature while irradiating the material with microwave radiation. The pressure is then reduced to a second pressure lower than the first pressure and the material is maintained in the vacuum chamber at the second pressure for a time period at a dehydrating temperature lower than the pasteurizing temperature while irradiating the material with microwave radiation.

Abstract: An apparatus and method for dehydrating biological materials, such as vaccines and microorganism cultures, in which the materials are dehydrated in an evacuated container which is in a microwave waveguide that is open to the atmosphere. The apparatus comprises means for freezing the container of biological material, a microwave generator, a waveguide, means for introducing the container into the waveguide, means for applying a vacuum to the container and means for removing the dehydrated material from the waveguide. In the method of the invention, the container of biological material is put in a microwave waveguide open to the atmosphere, a vacuum is applied to the container, the material is frozen and is radiated to dehydrate it. The dehydrated material is then removed from the waveguide.

Abstract: An apparatus and method for microwave vacuum-drying of organic materials such as food products. The dehydration apparatus (10) has a vacuum chamber (12) with a loading module (14) at one end and a discharge module (22) at the other. The vacuum chamber has access doors (80) spaced between the input end (16) and the discharge end (24) which provide operator and maintenance access. Microwave generators (86) are mounted on each access door and arranged to radiate through a microwave chamber and microwave-transparent window on the access door into the vacuum chamber. The waveguides on a respective access door are oriented to minimize microwave interference between the magnetrons on that door. A conveyor (60) in the vacuum chamber moves the organic material (96) on trays (18) through the vacuum chamber.

Abstract: An apparatus and method for microwave vacuum-drying of organic materials, such as food products. The apparatus has a microwave vacuum chamber 20, a loading module 36 to load containers 38 of the organic material into the vacuum chamber, a rotatable cylindrical cage 64 in the vacuum chamber for rotating the containers, a piston 114 for moving the rotating containers through the vacuum chamber, and means for unloading the containers of dehydrated material from the vacuum chamber. The apparatus may include an equilibration chamber 150 for cooling the dehydrated material under reduced pressure, and a transfer module 42 to transfer the containers from the vacuum chamber to the equilibration chamber. The apparatus has a microwave transparent window 54 for transmission of radiation into the vacuum chamber, and a gas jet 58, 60, 62 for blowing a stream of gas, such as air or nitrogen, into the vacuum chamber adjacent to the window.

Abstract: An apparatus 20 for microwave vacuum-drying organic materials such as foods and bioactives has a plurality of microwave generators 50 actuated so as to cause interference between their respective microwave streams and evenly distribute the microwave energy across the vacuum chamber 34. The microwave-transparent window 36 in the chamber is arranged so the organic material to be dried is moved across it on a conveyor belt 60 and the microwave energy passing into the chamber 34 immediately encounters the organic materials, thus attenuating the energy and reducing arcing.

Abstract: An apparatus 20 for microwave vacuum-drying organic materials such as foods and bioactives has a plurality of microwave generators 50 actuated so as to cause interference between their respective microwave streams and evenly distribute the microwave energy across the vacuum chamber 34. The microwave-transparent window 36 in the chamber is arranged so the organic material to be dried is moved across it on a conveyor belt 60 and the microwave energy passing into the chamber 34 immediately encounters the organic materials, thus attenuating the energy and reducing arcing.

Abstract: An apparatus 20 for microwave vacuum-drying organic materials such as foods and bioactives has a plurality of microwave generators 50 actuated so as to cause interference between their respective microwave streams and evenly distribute the microwave energy across the vacuum chamber 34. The microwave-transparent window 36 in the chamber is arranged so the organic material to be dried is moved across it on a conveyor belt 60 and the microwave energy passing into the chamber 34 immediately encounters the organic materials, thus attenuating the energy and reducing arcing.

Abstract: An apparatus 20 for microwave vacuum-drying organic materials such as foods and bioactives has a plurality of microwave generators 50 actuated so as to cause interference between their respective microwave streams and evenly distribute the microwave energy across the vacuum chamber 34. The microwave-transparent window 36 in the chamber is arranged so the organic material to be dried is moved across it on a conveyor belt 60 and the microwave energy passing into the chamber 34 immediately encounters the organic materials, thus attenuating the energy and reducing arcing.

Abstract: An apparatus (20) for dehydrating organic material in batches has a processing unit (22) having a microwave-vacuum chamber (34), an input module (28) and an output module (30), with a conveyor (54) for moving the material through the chamber on a microwave-transparent window. A material reservoir (68) is arranged to receive the material exiting the output module. A conveyor (78) external to the vacuum chamber conveys material that exits the reservoir to the input module. The vacuum chamber (34), reservoir (68) and external conveyor (78) are in fluid communication to operate at a common, reduced pressure. The organic material passes through the vacuum chamber multiple times to equilibrate and dry to the desired degree.

Abstract: An apparatus and method for microwave vacuum-drying of organic materials such as food products. The dehydration apparatus (20) has a vacuum chamber (24) with an input module (28) at one end and a discharge module (32) at the other. The vacuum chamber has access doors (80) spaced between the input end (30) and the discharge end (34) which provide operator and maintenance access. Microwave generators (86) are mounted on each access door and arranged to radiate through a microwave chamber and microwave-transparent window on the access door into the vacuum chamber. A pair of rollers (60) in the vacuum chamber rotates the container of organic material (112) about a horizontal axis, and a chain drive (64) pulls the containers along the rollers through the vacuum chamber.

Abstract: An apparatus and method for microwave vacuum-drying of organic materials such as food products. The dehydration apparatus (20) has a vacuum chamber (24) with an input module (28) at one end and a discharge module (32) at the other. The vacuum chamber has access doors (80) spaced between the input end (30) and the discharge end (34) which provide operator and maintenance access. Microwave generators (86) are mounted on each access door and arranged to radiate through a microwave chamber and microwave-transparent window on the access door into the vacuum chamber. A pair of rollers (60) in the vacuum chamber rotates the container of organic material (112) about a horizontal axis, and a chain drive (64) pulls the containers along the rollers through the vacuum chamber.

Abstract: A method for producing foams containing biological materials is described. A solid or semi-solid paste is formed by combining biologically active material with a protecting agent in an aqueous solvent. The paste formed is allowed to set, and may optionally then be apportioned into the desired shape. The paste may be frozen to allow formation of ice crystals to act as porogens. Subsequently, the paste is exposed to travelling wave radiant energy under vacuum (t-REV) for drying. This causes the solvent to boil off, leaving dried material containing the biologically active material, the protecting agent, and a relatively low water content. Biologically active materials which can be used include cells, microbial cultures, live attenuated microbes, probiotics, yeasts, enzymes, vaccines, proteins, and any heat-sensitive biological material. By directing energy via a travelling wave through a sample, good control of temperature and process conditions can be achieved.

Abstract: A method for producing foams, such as sponges, from hydrocolloids is described. A solid or semi-solid gel is formed by dissolving polymeric material in an aqueous solvent. The gel formed is allowed to set, and may optionally then be cut into the desired shape. The gel may be frozen to allow formation of ice crystals to act as porogens. Subsequently, the gel is exposed to a radiant energy field for drying under vacuum. This causes the solvent to boil and the foam or sponge is formed. Medicinally active ingredients may be included in the process, so that the sponge or foam formed contains the active ingredient dispersed within the structure. The method described provides an alternative to the conventional methods of particulate leaching or freeze drying.

Abstract: An apparatus for dehydrating a liquid sample of biological material has a microwave waveguide that is open to the atmosphere. It has a microwave generator, means for introducing a container of the material into the waveguide, means for evacuating the container, means for rotating the container and means for removing the container from the waveguide. It can include means for moving the container through the waveguide and for sealing it. In a dehydration method, a container of the liquid sample is put into the open waveguide, evacuated, rotated at high speed and microwaved. The container of dehydrated material is then removed from the waveguide. The apparatus and method are particularly suitable for dehydrating vaccines.

Abstract: An apparatus 20 for microwave vacuum-drying organic materials such as foods and bioactives has a plurality of microwave generators 50 actuated so as to cause interference between their respective microwave streams and evenly distribute the microwave energy across the vacuum chamber 34. The microwave-transparent window 36 in the chamber is arranged so the organic material to be dried is moved across it on a conveyor belt 60 and the microwave energy passing into the chamber 34 immediately encounters the organic materials, thus attenuating the energy and reducing arcing.

Abstract: An apparatus and method for microwave vacuum-drying of temperature-sensitive biological materials on a continuous flow-through basis, in which the materials are frozen, ground to frozen particles, dehydrated to a powder, and the powder collected. The apparatus (10) has a microwave generator (12) and waveguide (14), a freezing chamber (46) with a grinder (52), a rotatable dehydration chamber (18) in or adjacent to the waveguide, and a powder collector (82) to receive the powdered biological material. The apparatus operates under reduced pressure provided by a vacuum system (92) coupled to the powder collector (82).

Abstract: An apparatus for dehydrating a liquid sample of biological material has a microwave waveguide that is open to the atmosphere. It has a microwave generator, means for introducing a container of the material into the waveguide, means for evacuating the container, means for rotating the container and means for removing the container from the waveguide. It can include means for moving the container through the waveguide and for sealing it. In a dehydration method, a container of the liquid sample is put into the open waveguide, evacuated, rotated at high speed and microwaved. The container of dehydrated material is then removed from the waveguide. The apparatus and method are particularly suitable for dehydrating vaccines.

Abstract: An apparatus and method for microwave vacuum-drying of organic materials, such as food products. The apparatus has a microwave vacuum chamber 20, a loading module 36 to load containers 38 of the organic material into the vacuum chamber, a rotatable cylindrical cage 64 in the vacuum chamber for rotating the containers, a piston 114 for moving the rotating containers through the vacuum chamber, and means for unloading the containers of dehydrated material from the vacuum chamber. The apparatus may include an equilibration chamber 150 for cooling the dehydrated material under reduced pressure, and a transfer module 42 to transfer the containers from the vacuum chamber to the equilibration chamber. The apparatus has a microwave transparent window 54 for transmission of radiation into the vacuum chamber, and a gas jet 58, 60, 62 for blowing a stream of gas, such as air or nitrogen, into the vacuum chamber adjacent to the window.