GB2297472A - Preparing sauces - Google Patents

Abstract

A hot process for sauces has a first temperature level T1 of 48-58{C for addition of starch which has been homogenised with water. An anchor agitator, propeller agitator and diagonally opposite baffle provide effective mixing and even temperature and comminuted vegetable distribution in a cooking vessel having a steam jacket. Additional monitoring for temperature levels T2 and T3 is carried out for steam control where T2 is 75-88{C and T3 is a further 4-12{C higher than T2 and consistency tests provide an indication of when product may be pumped to a holding tank.

Description

"A production process for sauces" The invention relates to a process for the production of sauces, and more particularly to a hot process whereby the sauce is heated to a sufficient temperature to achieve sterility. Sauces which are produced by such a process typically include tomato ketchup, bolognese sauce, ethnic, ready-made and pasta sauces generally.

In such hot processes, it is important to achieve a sufficiently high temperature so that there is guaranteed sterility of the product. However, control of the process becomes complex when raw materials used include comminuted food products such as mushrooms as the fabric and taste of such materials may become diminished through excessive heat. A still further problem can arise in that thickening materials such as starch may break down to have a very low viscosity.

Accordingly, the invention is directed towards providing a production process which ensures sterility of the product, while at the same time maintaining taste and structure of constituent materials within the sauce and consistency of the sauce. Another object is to provide a process which allows quick change-over between batches.

According to the invention, there is provided a hot process for sauce production, the process comprising the steps of: weighing raw material solids; setting a water meter and controlling delivery of a pre-set quantity of water to a cooking vessel, the water meter setting being adjusted to allow for off-line mixing of starch; activating an anchor agitator having agitator members conforming to the base of the mixing vessel and also a propeller agitator mounted at an angle to the vertical at one side of the vessel; gradually opening a steam valve to allow injection of steam to a steam jacket surrounding at least a portion of the internal skin of the mixing vessel to heat the product in the vessel; mixing starch with water off-line to provide an homogenous mix; monitoring temperature of the water and before a first temperature level is detected adding the waterlstarch mixture, said first temperature level being in the range of 480C-58"C; adding additional raw materials and subsequently monitoring temperature of the product in the vessel to determine when it reaches a second, higher temperature level in the range of 75 C to 880C; when the second temperature level is reached, shutting off steam injection to the steam jacket and leaving the previously-injected steam in the jacket; monitoring temperature of the product to determine when it reaches a third temperature level which is in the range of 4"C-120C higher than the second temperature level; when the product reaches the third temperature level, taking samples and analysing the samples to determine if the product has a desired correct consistency; and when the product has the correct consistency and the third temperature level has been reached, pumping the product to a holding tank.

In one embodiment, distribution of particulate matter and distribution of temperature in the product is assisted by use of a vertically-directed baffle.

Preferably, the propeller agitator is mounted at a position diametrically opposite the baffle in the vessel.

In another embodiment, temperature is monitored by reference to a thermometer mounted on the baffle.

In a still further embodiment, steam is injected at a pressure in the range of 7 to 8 bar.

Preferably, the process comprises the further step of scraping the bottom of the mixing vessel by use of scrapers hinged to the anchor agitator.

The invention will be more clearly understood from the following description of some embodiments thereof, given by way of example only with reference to the accompanying drawings in which: Fig 1 is a flow chart of a production process of the invention; Fig 2 is a diagrammatic side view of a cooking vessel used in the process; Fig 3 is a plan view of the vessel of Fig 2.

Referring to the drawings, there is illustrated a hot process 1 of the invention for the production of sauces.

The process is described as "hot" because the product requires a cooking stage and in some cases is maintained hot right through to packing.

In step 10 of the process, various constituent raw material solids are weighed such as sugar, salt, spices, or vegetables such a comminuted mushrooms.

In step 11, water delivery to a cooking vessel such as that illustrated in Figs 2 and 3 is controlled. The cooking vessel shown in Figs 2 and 3 is indicated by the numeral 30 and comprises an inner skin 31 of generally cylindrical shape at the top and having a domed bottom.

There is also a layer of insulation 32 around the domed portion of the inner skin 31, and this forms a steam jacket 33 which extends around the domed part of the vessel 30. There is a steam inlet 34 and a steam outlet 35 through the insulation 32. Further, there is an air vent 36 at a high level in the steam jacket 33. A top cover for the vessel 30 has a water inlet 37. The bottom of the vessel 30 has a product outlet 38 connected to a pump. The vessel 30 further comprises a motor assembly 39 driving a central vertical shaft 40 which is in turn connected to an anchor agitator 41. The anchor agitator 41 extends around the full depth of the domed part of the vessel. In addition, there is a propeller agitator 42 mounted at an angle to the vertical at one side of the shaft 40.To further assist in agitation of the product, there is a baffle 43, the configuration of which is best shown in plan in Fig 3. The baffle 43 is on the side of the shaft 40 diametrically opposite the propeller agitator 42. A thermometer 44 having a readout 45 is secured to the baffle 43.

As shown in particular in Fig 3, there is a set of support legs 47 for the vessel 30 and an opening 48 for the propeller agitator 42.

The product outlet 38 is connected to a holding tank mounted at a high level to provide a gravity feed to a bottling system.

Control of the water delivery in step 11 is achieved by setting a desired quantity of water for the batch, an amount of water required for mixture of starch being deducted from this quantity.

In step 12, both the anchor agitator 41 and the propeller agitator 42 are activated to agitate the water. There is then a gradual opening of the steam valve connected to the steam inlet 34 in step 13 for injection of steam into the steam jacket 33 at a pressure of between 7 and 8 bar.

This causes the water to be gradually heated and while this is happening, starch is mixed off-line with the desired quantity of water. In this embodiment, a quantity of 10-15 kilograms of starch is mixed with 25 litres of water for a total product batch of 500 litres. This has been found suitable for providing an homogenous mix.

During off-line mixture of the starch, temperature of the water in the vessel 30 is monitored as indicated by the step 15 until a first temperature level T1 is reached. In this embodiment, the desired temperature level T1 is 50"C, however it has been found that any value within the range 480C to 58"C is suitable. It has been found that at these temperatures the starch does not break down to a low viscosity and is therefore suitable to act as a thickening agent for the product with a long shelf life. It has also been found that the arrangement of the thermometer 44 being mounted on the baffle 43 provides a particularly accurate reading of temperature within the vessel 30.

Further, impingement of the product on the baffle at the particular position helps to distribute the materials consistently throughout the product.

Just before the temperature T1 is reached, the pre-mixed starch is added in step 17 and then in step 18 various raw materials are added. The agitators may be switched off for addition of vegetables. These include sugar, comminuted vegetables such as mushrooms, spices, comminuted meat and other appropriate raw materials for the sauce being produced. Each material is added in turn as indicated by the steps 18 and 19 and as indicated by the step 20 there is on-going monitoring of the temperature within the vessel 30. At this stage, the product is cooking and it is very important to determine accurately when the product reaches a second temperature level, T2. The value of the temperature T2 depends on the product being produced. For all products it is in excess of 70"C to ensure that the product is cooked.However, above this temperature there is a range of different desirable levels for T2 such as 80"C for tomato ketchup or 850C for pasta sauce. In general, it is in the range 75"C to 880C. Immediately when the temperature level T2 is reached, the steam is shut off in step 22, with the outlet being closed so that the steam within the jacket 33 remains in place. It has been found that by doing this the temperature slowly rises from the level T2 to the desired third temperature level T3. This is the temperature at which the product is comprehensively cooked.

Again, the thermometer display 45 is monitored until a temperature level T3 is reached as indicated by the numerals 23 and 24. The temperature level T3 may be 95 0C for pasta sauce, or 850C for tomato ketchup. In general, T3 is in the range of 40C to 120C higher than T2. When this temperature is reached, samples may be removed for texture analysis to ensure that consistency of the product is correct. This is an important step as it provides the signal as to when the product may be dispensed to the holding tank. It takes only some minutes for this stage to be reached, however, it is not possible to determine this stage by simply monitoring time while the product is approximately at the temperature level T3. It is important to check that the texture is correct by testing samples.

Provided the temperature and the quality is correct, in step 25 the product is pumped to a holding tank which is mounted at a high level so that there is a pressure head for a filling station of a bottling plant.

After the batch has been emptied from the vessel 30, scrapers 50 which are hinged to the external surface of the anchor agitator 41 are operated to ensure that the bottom of the tank is completely free of remaining particles such as mushroom pieces.

At the filling station, the product is injected at a temperature just slightly lower than T3 and the jar or can is immediately sealed to ensure sterility of the product.

Once the sauce is pumped to the holding tank and the scrapers 50 have operated, water for the next batch may be pumped in. This begins a new process, possibly for a different sauce. It will be appreciated that the invention allows production of small batches and quick batch change-overs.

It has been found that by monitoring the production process according to the three temperature levels there is very close control and a high quality product is achieved.

It has also been found that the arrangement of agitators is particularly efficient at agitation of this type of product, particularly where there is a comminuted raw material such as a vegetable in suspension. The arrangement of the baffle 43 is particularly effective at providing for even distribution of temperature and solids and the temperature reading taken from this particular position is accurate. It has also been found that by injection of the steam in the manner described temperature can be controlled very well to provide a consistent good quality product having the correct viscosity and texture in particular.

The invention is not limited to the embodiments hereinbefore described. For example, the starch may be added at an earlier time, the important point being that it is not added at a higher temperature than T1. Further, it is envisaged that for some sauces an homoginiser of the shearing or colloid-mill type may be used in addition to the agitators.

Claims (8)

1. A hot process for sauce production, the process comprising the steps of: weighing raw material solids; setting a water meter and controlling delivery of a pre-set quantity of water to a cooking vessel, the water meter setting being adjusted to allow for off-line mixing of starch; activating an anchor agitator having agitator members conforming to the base of the mixing vessel and also a propeller agitator mounted at an angle to the vertical at one side of the vessel; gradually opening a steam valve to allow injection of steam to a steam jacket surrounding at least a portion of the internal skin of the mixing vessel to heat the product in the vessel; mixing starch with water off-line to provide an homogenous mix;; monitoring temperature of the water and before a first temperature level is detected adding the water/starch mixture, said first temperature level being in the range of 48"C- 580C; adding additional raw materials and subsequently monitoring temperature of the product in the vessel to determine when it reaches a second, higher temperature level in the range of 750C to 880C; when the second temperature level is reached, shutting off steam injection to the steam jacket and leaving the previously-injected steam in the jacket; monitoring temperature of the product to determine when it reaches a third temperature level which is in the range of 40C-120C higher than the second temperature level;; when the product reaches the third temperature level, taking samples and analysing the samples to determine if the product has a desired correct consistency; and when the product has the correct consistency and the third temperature level has been reached, pumping the product to a holding tank.

2. A process as claimed in claim 1 wherein distribution of particulate matter and distribution of temperature in the product is assisted by use of a vertically-directed baffle.

3. A process as claimed in claim 2, wherein the propeller agitator is mounted at a position diametrically opposite the baffle in the vessel.

4. A process as claimed claims 2 or 3, wherein temperature is monitored by reference to a thermometer mounted on the baffle.

5. A process as claimed in any preceding claim, wherein steam is injected at a pressure in the range of 7 to 8 bar.

6. A process as claimed in any preceding claim comprising the further step of scraping the bottom of the mixing vessel by use of scrapers hinged to the anchor agitator.

7. A process substantially as hereinbefore described, with reference to and as illustrated in the accompanying drawings.

8. A sauce whenever produced by a process as claimed in any preceding claim.