GB2300344A

GB2300344A - Heat treatment of dairy products

Info

Publication number: GB2300344A
Application number: GB9507681A
Authority: GB
Inventors: Raymond Sidney Pierce
Original assignee: GENICE FOODS Ltd
Current assignee: GENICE FOODS Ltd
Priority date: 1995-04-13
Filing date: 1995-04-13
Publication date: 1996-11-06
Also published as: GB9507681D0

Abstract

In apparatus for and method of treating an edible product such as a dairy product, product is pumped by a pump 3 to treatment vessels 4 and 5 where it is heated by hot water flowing through jackets 8. Treated product then flows to a holding tank 18. An electrical control circuit monitors the temperature of the product by thermostat 24 and controls the heat supplied to the treatment vessels. The product dwell time in the treatment vessels 4 and 5 is at least ten minutes, the temperature of the hot water 102{C and the product temperature in the holding tank 18 in the range 70{C to 74{C preferably 72{C.

Description

APPARATUS AND METHOD FOR THE TREATMENT OF AN EDIBLE PRODUCT The present invention relates to an apparatus and method for the treatment of an edible product. The apparatus and method are particularly, but not exclusively applicable to the treatment of products requiring pasteurisation such as dairy products. Presently known apparatus and methods are aseptic. Aseptic equipment is expensive to obtain and maintain and associated processes are correspondingly time consuming and expensive. An object of embodiments of the invention is to overcome or mitigate these disadvantages.

According to one aspect of the present invention, there is provided apparatus for the treatment of an edible product comprising a treatment vessel, supply means for supplying edible product to the treatment vessel, means for supplying heat to the treatment vessel in order to maintain the temperature of the product within a predetermined temperature range, monitoring means for monitoring the temperature of the treated product and control means for controlling heat supply to ensure that the temperature is maintained within the above mentioned range.

According to another aspect of the present invention, there is provided a method for the treatment of an edible product including the steps of supplying product to a treatment vessel, heating the product to a temperature within a predetermined temperature range, monitoring the temperature of the treated product and controlling the amount of heat supplied to the treatment vessel to ensure that the temperature is maintained within the above mentioned range.

In a preferred embodiment of the invention, the temperature range within which the temperature of the product is maintained is 700 to 740C and the preferred temperature within that range is 720C. The supply means comprises a product container and a variable speed metering pump disposed in the outlet from the container. Advantageously the pump is a gear pump.

The speed of the pump is controlled so that the product dwell time within the treatment vessel is at least ten minutes. The treatment vessel comprises a housing defining a chamber through which product flows. A motor driving a vane within the chamber directs product towards the wall of the housing to enhance heat exchange. The means for supplying heat comprises a jacket surrounding the housing and a hot water supply. Water is fed to the jacket from the supply to heat in the product flowing through the chamber.

The monitoring means comprises a thermostat which measures the temperature of treated product in a holding tank into which product flows from the treatment vessel. The signal from the thermostat is fed back to the control means which controls a water pump pumping water from the hot water supply to the jacket to increase or decrease the heat supplied to the product. The pump speed is increased or decreased respectively to increase or decrease respectively the amount of heat fed to the product. The water supply is contained in a container and is maintained at a temperature of 1020C by means of steam heating. The supply of steam is controlled to maintain the water at this temperature. The temperature is monitored by a thermostat and the signal from the thermostat employed to control the steam supply to maintain the water at the desired temperature.This steam control forms part of the above mentioned control means. The output from the holding tank is fed to a commercial carton filling machine. After filling the vacuum sealing the sealed cartons are inverted so that heat flows to the lids of the cartons.

In order that the invention may be more clearly understood, one embodiment thereof will now be described, by way of example, with reference to the single figure of the accompanying drawing which shows diagrammatically one form of apparatus according to the invention.

Referring to the drawing, the apparatus comprises means I, such as a container, for the supply of raw food product. In this particular example the product is soya based yoghurt, appropriate additives and fruit pieces.

An outlet 2 from the supply means I leads to a variable speed metering pump 3. The metering pump 3 is a gear pump but other types of metering pump could be used. The outlet from the pump is connected to two treatment vessels 4 and 5 connected in series but disposed physically in parallel in order to produce a more compact arrangement. If feasible, these two treatment vessels may be replaced by a single vessel or, if desired, more than two vessels may be employed.

Each treatment vessel 4,5 is generally cylindrical and comprises a housing 6 defining a chamber 7 surrounded by a jacket 8. Two shafts 9 supporting vanes 10 extend into respective chambers 7. Motors II are drivably connected by driving belts 12 to respective shafts 9. In operation, the motors ll rotate the shafts 9 and thereby the vanes 10 to direct product in the chambers 7 against the walls of the chambers in order to enhance the heat transfer from hot water flowing through respective jackets 8. Water is supplied to the jackets 8 from a water reservoir 13 via a water pump 14 and on/off valve 15. The water in the reservoir 13 is steam heated but other form of heating such as electrical heating or gas may be used if desired.

An outlet 17 leads from the second 5 in series of the treatment vessels 4,5 to an open treated product holding tank 18 which in turn supplies a conventional carton filling machine 19 through four outlets 20. Arrows 21 and 22 indicate the flow of empty cartons into the machine and the flow of filled cartons out of the machine. After filling the cartons are vacuum sealed and inverted so that the heat from the product heats up and sterilises the lids of the cartons.

The apparatus includes an electrical control circuit which in operation monitors and controls the process carried out in the apparatus in accordance with the closely defined and adhered to process parameters. This control circuit comprises a thermostat 23 disposed in the hot water reservoir 13 and a thermostat 24 disposed in the holding tank 18. The thermostat 23 is set to maintain a temperature of 1020C, or other appropriate temperature, in the reservoir 13 by controlling the supply of steam automatically from steam supply 25 through steam supply line 26 to reservoir 13. The thermostat 24 is set to maintain a temperature in the holding tank 18 in the range 700 to 740C and preferably 720C, or other appropriate range and temperature. The signal from thermostat 24 is fed via line 27 to a control 28.This control 28 controls via control line 29 the water pump 16 to increase or decrease water flow to the jackets 8 and thereby increase or decrease the flow of heat to the product flowing through the treatment vessels 4 and 5 in order to maintain the product at the correct temperature.

The variable speed pump 3 is set to supply product from means I at a rate such that the dwell time of product in the vessels 4 and 5 is approximately ten minutes. Advantageously the pump 3 is also controlled from control 28 in order to maintain the correct rate or product flow at the correct temperature.

With the above described arrangement, yoghurt, with or without fruit pieces, can be pasteurised and packaged in equipment of much less complexity than hitherto and under much less onerous conditions. Provided the seal on the packaged product is not damaged the product may have a shelf life of several months. The temperature control is important. If the temperature is not high enough, the yoghurt will not be pasteurised. If the temperature is too high the product will be denatured.

It will be appreciated that the above embodiment has been described by way of example only and that many variations are possible without departing from the scope of the invention. For example the controls 25 and 28 may be integrated and controlled by an appropriately controlled microprocessor.

Claims

I. Apparatus for the treatment of an edible product comprising a treatment vessel, supply means for supplying edible product to the treatment vessel, means for supplying heat to the treatment vessel in order to maintain the temperature of the product within a predetermined temperature range, monitoring means for monitoring the temperature of the treated product and control means for controlling heat supply to ensure that the temperature is maintained within the above mentioned range.
2. Apparatus as claimed in claim I, in which the supply means comprises a product container and a variable speed metering pump disposed in the outlet from the container.
3. Apparatus as daimed in claim 2, in which the variable speed metering pump comprises a gear pump.
4. Apparatus as claimed in claim 1, 2 or 3, in which the treatment vessel comprises a housing defining a chamber through which, in operation, product flows.
5. Apparatus as claimed in claim 4, in which a vane is disposed within the chamber and means are provided for driving the vane to direct product towards the wall of the housing.
6. Apparatus as claimed in claim 4 or 5, in which the means for supplying heat comprises a jacket surrounding the housing arranged to receive hot water from a hot water supply.
7. Apparatus as claimed in any preceding claim, in which the monitoring means comprises a thermostat operative to measure temperature of treated product in a holding tank into which product flows in operation from the treatment vessel.
8. Apparatus as claimed in claim 7, in which the control means comprises a water pump the speed of which is varied in dependence upon a signal received from the thermostat to control the amount of heat supplied.
9. Apparatus as claimed in claim 6, in which the control means comprise means for controlling a steam supply for maintaining the temperature of the water from the hot water supply.
10. Apparatus for the treatment of an edible product substantially as hereinbefore described with reference to the accompanying drawing.
II. A method for the treatment of an edible product including the steps of supplying product to a treatment vessel, heating the product to a temperature within a predetermined temperature range, monitoring the temperature of the treated product and controlling the amount of heat supplied to the treatment vessel to ensure that the temperature is maintained within the above mentioned range.
12. A method as claimed in claim II, in which the temperature of the product is maintained in the range 700 to 740C.
13. A method as claimed in claim II or 12, in which the temperature of the product is maintained at 720C.
14. A method as claimed in claim 11, 12 or 13, in which the product flows through a chamber in a treatment vessel and is directed towards the wall of a housing defining the chamber in order to enhance heat exchange.
15. A method as claimed in claim 14, in which the product is heated by supplying hot water to a jacket surrounding the housing to supply heat to the product flowing through the chamber.
16. A method as claimed in any of claims Il to 15, in which the temperature of the treated product is monitored by measuring its temperature in a holding tank into which it flows from the treated vessel.
17. A method as claimed in claim 15, in which the amount of heat supplied is controlled by varying the flow rate of the hot water.
18. A method as claimed in claim 15 or 17, in which the temperature of the hot water is maintained by steam heating.
19. A method as claimed in claim 15, 17 or 18, in which the temperature of the hot water is maintained at 1020C.
20. A method as claimed in any of claims Il to 19, in which the product is pumped to the treatment vessel and the speed of the pump is controlled so that product dwell time within the treatment vessel is at least ten minutes.
21. A method for the treatment of an edible product substantially as hereinbefore described with reference to the accompanying drawing.