Claims
- 1. A method for heat-treating and drying food products comprising the steps of:loading the products to be treated into a not tightly closed transport receptacle; charging said transport receptacle into a charging lock chamber, bringing a pressure of the charging lock chamber to a pressure of a treatment chamber; continuously transferring said transport receptacle from said charging lock chamber across said treatment chamber into a discharging lock chamber by means of a main conveyor means, while maintaining the pressure of the treatment chamber at vacuum, and heat-treating said product with microwave radiation in said treatment chamber, adjusting a pressure in the discharging lock chamber to atmospheric pressure, and discharging said not tightly closed transport receptacle from said discharging lock chamber and bringing it to said atmosphere.
- 2. The method as set forth in claim 1, wherein a plurality of transport receptacles is conveyed, one after the other in a continuous line across said main treatment chamber.
- 3. The method as set forth in claim 1, wherein in transferring said transport receptacle into said treatment chamber and/or into said discharging lock chamber a pressure equalization is undertaken.
- 4. The method as set forth in claim 1, wherein in transferring said transport receptacle into said treatment chamber and/or into said discharging lock chamber one connecting door each of said treatment chamber is opened and reclosed.
- 5. The method as set forth in claim 1, wherein said product to be treated is arranged in several layers in said transport receptacle.
- 6. The method as set forth in claim 1, wherein heat-treating of said product is done in two steps, said product being broken up or puffed up by means of microwave radiation in said first step and broken-up product being dried by means of infrared and/or microwave radiation for obtaining a well rehydratable product having an instant character in said second step.
- 7. The method as set forth in claim 1, wherein said heat-treating is performed in said treatment chamber at a reduced atmospheric pressure, preferably in the range 20-100 mbar.
- 8. The method as set forth in claim 1, wherein pre-drying of said product, preferably to a residual moisture content of approx. 40%, is performed in a treatment zone upstream of said treatment chamber, and/or after drying said product, preferably to a residual moisture content of approx. 2 to 6%, is performed in a treatment zone downstream of said treatment chamber.
- 9. A transport receptacle for use in a method as set forth in claim 1, wherein said transport receptacle is configured in the shape of a dish.
- 10. The transport receptacle as set forth in claim 9, the bottom thereof being provided with holes.
- 11. The method defined in claim 1, further comprising the steps of:dividing the products into a plurality of pieces, wherein said products are selected from the group consisting of dried fruits and dried vegetables, heat-treating the pieces in a pre-charging chamber upstream from the charging lock chamber by utilizing at least one micro-wave source so that a cellular break-up and puffing up of said food products occur for obtaining well-hydratable food having an instant character.
- 12. The method defined in claim 11, wherein the step of dividing the food products is selected from the group consisting of shredding, chopping and milling.
- 13. The method defined in claim 12, wherein the food products are milled into a food powder.
- 14. A Method as set forth in claim 1, wherein said food product is heat-treated, in addition to said microwave radiation, with infrared radiation.
- 15. An apparatus for heat-treating and drying food products, comprising:a plurality of not tightly closed transport receptacles for receiving products; a charging lock chamber provided with a first conveyor means for transporting the not tightly closed transport receptacle; pressure means for gradually lowering a pressure in the charging lock chamber to a first pressure below the atmospheric pressure; a treatment chamber provided with a main conveyor for conveying said transport receptacle across the treatment chamber; at least one microwave radiation source for heating said products in the treatment chamber; means for maintaining the first pressure within the treatment chamber; and a discharging lock chamber provided with a second conveyor means for discharging said transport receptacle from said apparatus, the not tightly closed receptacle being continuously conveyed from the charging lock chamber across the treatment chamber and into the discharging lock chamber.
Priority Claims (1)
Number |
Date |
Country |
Kind |
198 04 386 |
Feb 1998 |
DE |
|
PRIOR APPLICATION
This Application is a Continuation Application of Ser. No. 09/244,278 now U.S. Pat. No. 6,297,479 filed Feb. 3, 1999 which claims priority from German Application No. DE 198 04 386.4 filed Feb. 4, 1998.
US Referenced Citations (14)
Foreign Referenced Citations (6)
Number |
Date |
Country |
1604798 |
Nov 1973 |
DE |
295 17 499 U |
Mar 1997 |
DE |
2071833 |
Sep 1981 |
GB |
62-158476 |
Jul 1987 |
JP |
7-255388 |
Oct 1995 |
JP |
11-83327 |
Feb 1999 |
JP |
Continuations (1)
|
Number |
Date |
Country |
Parent |
09/244278 |
Feb 1999 |
US |
Child |
09/911303 |
|
US |