GB2120076A

GB2120076A - Cooling sterilised products

Info

Publication number: GB2120076A
Application number: GB08214603A
Authority: GB
Inventors: John Kenneth Taylor
Original assignee: Individual
Current assignee: Individual
Priority date: 1982-05-19
Filing date: 1982-05-19
Publication date: 1983-11-30
Also published as: GB2120076B

Abstract

A product, such as food, is sterilised by heating in vessel 10, transferred by suction into evacuated vessel 16, using pump 24, by spraying it from line 14 which degasses the product. The product falls into water 18 and is further cooled by vacuum evaporation. After cooling, sterile air is admitted via line 28 to restore pressure before discharging the cooled product via 34. <IMAGE>

Description

SPECIFICATION Cooling of heated products The invention relates to cooling of heated products and is particularly but not exclusively suitable for the cooling of hot cooked foodstuffs or pharmaceuticals.

It is often necessary, after a product such as a foodstuff or pharmaceutical has been heated during cooking or processing that it must be cooled before it can be subjected to further processing. For example in the preparation of pies itis necessary to produce a heated sterilized filling which requires cooling before depositing onto pastry, otherwise the pastry will be degraded.

It has hitherto been the practice to cool such products by conventional vacuum evaporation techniques in the cooking vessel or heat-treatment vessel.

There are a number of disadvantages to this method, one being that the cooking vessel can only be utilised for its proper purpose of cooking for part, typically less than half ofthetime available,and airwhich is entrained in the cooking product expands underthe vacuum evaporation causing the whole productto expand within the cooking vessel and cause denaturing ofthe product. In orderto obviate this, then either the vacuum has to be applied at a very low rate to inhibit the expansion and allowthe entrained airto escape slowly or air has to be admitted to the vessel to depress the expanding volume of product possibly leading to contamination, under conditions which are typically ideal for the rapid growth of bacteria.

The invention provides therefore a method of treating a hot product comprising the steps of transferring the product, whilst still hot from the heating vessel by suction into a second vessel, the product being discharged into the second vessel under reduced pressure to at least partially degass the foodstuffand/or partially cool the foodstuff, and then further cooling the foodstuff by vacuum evaporation.

Preferablywateris added to the second vessel to replace water lost from the product during heating, transfer or cooling. The water is preferably introduced to the second vessel before the product is added, the product initially introduced into the vessel falling into the water so that the water acts as a cushion to inhibit pysical damage to the texture ofthe product as it arrives in the second vessel.

Afterthevacuum evaporative cooling the second vessel is preferably restored to ambient pressure by introducing sterile air, preferably airfiltered using a microbiological filter.

By meansofthe invention, once the heated product hasbeentransferred into thesecond vessel, the heating vessel can be used once again for its proper purpose i.e. heating the product so reducing down time.Thussavingscan be made in respectofthe energy which is wasted in repeatedly heating and cooling the heating vessel. The addition of water in the secondvessel increases the overall yield of product and counteractsthe drying ofthe product during processing.

An embodiment ofthe invention will now be described byway of example and with reference to the accompanying drawing the single figure of which is a schematic diagram illustrating the method of the invention.

The apparatus shown in the drawing comprises a cooking vessel 10 in which a foodstuff is brought into a hot sterile cooked condition, the foodstuff having a proportion of non-condensable material introduced by virtue of the cooking process, such as entrained air.

Atransfer line 12 having a valve 14 connects the cooking vessel 10 to a second vessel 16 in the bottom ofwhich is placed a quantity of sterile water 18. The pressure of the interior of the second vessel can be reduced by means of a vacuum line 20 leading via a valve 22 to a vacuum pump 24. The pressure in the interior of the second vessel can be returned from low pressure to ambient pressure by the introduction of air along an air line 28 via microbiological filter 30, ingress of air being controlled by a valve 32. A valve 34 is provided to allow discharge ofthe cooled product on return ofthe internal pressure ofthe second vessel to ambient pressure.

The apparatus is operated asfollows: A quantity of sterile water 18 is added to the second vessel 16.

Heated foodstuff, after cooking has been completed in the cooking vessel 10, is transferred by suction to the second vessel by opening valves 14 and 22 with valves 32 and 34 closed and allowing the vacuum pump 24to reduce the pressure in the vessels so drawing the foodstuff from the cooking vessel 10 into the top ofthe second vessel 16. As the foodstuff is discharged by spraying it from the line 14 it is largely degassed by virtue of the factthat a large surface area ofthe foodstuff is subjected to the vacuum. The foodstufffalls into the water 18, and when transfer of allthefoodstufffromthe cooking vessel to the second vessel is complete the valve 14 is closed and the foodstuff and water mixture is subjected to additional cooling by vacuum evaporation.When the temperature of the foodstuff has been sufficiently reduced the valve 22 is closed and the valve 32 opened two allow sterile air along the air line 28 to restore pressure within the second vessel to ambient. The cooled product is discharged through the valve 32.

Various modifications may be made within the scope of the invention for instance the transfer line may be of any suitable material and may be flexible.

The cooking vessel and second vessel may be made from any appropriate material typically stainless steel and the source of sterile air may be supplied by means other than through a microbiological filter. The vacuum pump may be of any appropriate type.

Whilst endeavouring in the foregoing specification to draw attention to those features ofthe invention believed to be of particular importance is should be understood that the applicant claims protection in respect of any patentable feature or combination of features hereinbefore referred to whether or nor particular emphasis has been placed thereon.

CLAIMS (Filed on 26/4/83) The drawing originally filed was informal and the print here reproduced is taken from a later filed formal copy.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Cooling of heated products The invention relates to cooling of heated products and is particularly but not exclusively suitable for the cooling of hot cooked foodstuffs or pharmaceuticals. It is often necessary, after a product such as a foodstuff or pharmaceutical has been heated during cooking or processing that it must be cooled before it can be subjected to further processing. For example in the preparation of pies itis necessary to produce a heated sterilized filling which requires cooling before depositing onto pastry, otherwise the pastry will be degraded. It has hitherto been the practice to cool such products by conventional vacuum evaporation techniques in the cooking vessel or heat-treatment vessel. There are a number of disadvantages to this method, one being that the cooking vessel can only be utilised for its proper purpose of cooking for part, typically less than half ofthetime available,and airwhich is entrained in the cooking product expands underthe vacuum evaporation causing the whole productto expand within the cooking vessel and cause denaturing ofthe product. In orderto obviate this, then either the vacuum has to be applied at a very low rate to inhibit the expansion and allowthe entrained airto escape slowly or air has to be admitted to the vessel to depress the expanding volume of product possibly leading to contamination, under conditions which are typically ideal for the rapid growth of bacteria. The invention provides therefore a method of treating a hot product comprising the steps of transferring the product, whilst still hot from the heating vessel by suction into a second vessel, the product being discharged into the second vessel under reduced pressure to at least partially degass the foodstuffand/or partially cool the foodstuff, and then further cooling the foodstuff by vacuum evaporation. Preferablywateris added to the second vessel to replace water lost from the product during heating, transfer or cooling. The water is preferably introduced to the second vessel before the product is added, the product initially introduced into the vessel falling into the water so that the water acts as a cushion to inhibit pysical damage to the texture ofthe product as it arrives in the second vessel. Afterthevacuum evaporative cooling the second vessel is preferably restored to ambient pressure by introducing sterile air, preferably airfiltered using a microbiological filter. By meansofthe invention, once the heated product hasbeentransferred into thesecond vessel, the heating vessel can be used once again for its proper purpose i.e. heating the product so reducing down time.Thussavingscan be made in respectofthe energy which is wasted in repeatedly heating and cooling the heating vessel. The addition of water in the secondvessel increases the overall yield of product and counteractsthe drying ofthe product during processing. An embodiment ofthe invention will now be described byway of example and with reference to the accompanying drawing the single figure of which is a schematic diagram illustrating the method of the invention. The apparatus shown in the drawing comprises a cooking vessel 10 in which a foodstuff is brought into a hot sterile cooked condition, the foodstuff having a proportion of non-condensable material introduced by virtue of the cooking process, such as entrained air. Atransfer line 12 having a valve 14 connects the cooking vessel 10 to a second vessel 16 in the bottom ofwhich is placed a quantity of sterile water 18. The pressure of the interior of the second vessel can be reduced by means of a vacuum line 20 leading via a valve 22 to a vacuum pump 24. The pressure in the interior of the second vessel can be returned from low pressure to ambient pressure by the introduction of air along an air line 28 via microbiological filter 30, ingress of air being controlled by a valve 32. A valve 34 is provided to allow discharge ofthe cooled product on return ofthe internal pressure ofthe second vessel to ambient pressure. The apparatus is operated asfollows: A quantity of sterile water 18 is added to the second vessel 16. Heated foodstuff, after cooking has been completed in the cooking vessel 10, is transferred by suction to the second vessel by opening valves 14 and 22 with valves 32 and 34 closed and allowing the vacuum pump 24to reduce the pressure in the vessels so drawing the foodstuff from the cooking vessel 10 into the top ofthe second vessel 16. As the foodstuff is discharged by spraying it from the line 14 it is largely degassed by virtue of the factthat a large surface area ofthe foodstuff is subjected to the vacuum. The foodstufffalls into the water 18, and when transfer of allthefoodstufffromthe cooking vessel to the second vessel is complete the valve 14 is closed and the foodstuff and water mixture is subjected to additional cooling by vacuum evaporation.When the temperature of the foodstuff has been sufficiently reduced the valve 22 is closed and the valve 32 opened two allow sterile air along the air line 28 to restore pressure within the second vessel to ambient. The cooled product is discharged through the valve 32. Various modifications may be made within the scope of the invention for instance the transfer line may be of any suitable material and may be flexible. The cooking vessel and second vessel may be made from any appropriate material typically stainless steel and the source of sterile air may be supplied by means other than through a microbiological filter. The vacuum pump may be of any appropriate type. Whilst endeavouring in the foregoing specification to draw attention to those features ofthe invention believed to be of particular importance is should be understood that the applicant claims protection in respect of any patentable feature or combination of features hereinbefore referred to whether or nor particular emphasis has been placed thereon. CLAIMS (Filed on 26/4/83) The drawing originally filed was informal and the print here reproduced is taken from a later filed formal copy.

1. A method of treating a hotproductcomprising the steps oftransferring the product, whilst still hot from a heating vessel by suction into a second vessel, the product being discharged intothesecondvessel under reduced pressure to at least partially degassthe foodstuff and/or partially cool the foodstuff, and then furthercoolingthefoodstuffbyvacuum evaporation.

2. A method as claimed in claim 1, in which water is added to the second vessel to replace water lost from the product during heating, transferor cooling.

3. A method as claimed in claim 2, in which the water is introduced to the second vessel before the product is added.

4. Amethod as claimed in any one of claims 1 to 3, in which after the vacuum evaporative cooling the second vessel is restored to ambient pressure by introducing sterile air.

5. A method as claimed in claim 4, in which the air is filtered using a microbiological filter.

6. A method as claimed in any one of the preceding claims in which rotatable paddles are provided in the second vessel to stir mixture therein.

7. A method oftreating a hot product, substantially as hereinbefore described with reference to the accompanying drawing.

8. Any novel subject matter or combination including novel subject matter herein disclosed, whether or notwithin the scope of or relating to the same invention as any ofthe preceding claims.