DE202004021080U1 - Industrial production of peeled fruit or vegetable, especially potatoes, with long shelf life, by cooking with steam under elevated pressure then cooling under reduced pressure in reaction vessel - Google Patents

Abstract

Industrial production of preserved, peeled fruit or vegetables involves placing the peeled produce (10) and an exact, calculated amount of water (11) in a reaction vessel (1), such that the produce does not contact liquid water, tightly closing the lid (3), supplying energy to heat the water, so that steam pressure increases to a maximum value limited by a valve, after a specific boiling time discharging water via an outlet valve (14) in the vessel base, so that reduced pressure is created, thus evaporating bound water in, and rapidly cooling, the produce; and after cooling opening the lid and transferring the produce to an aseptic packaging station. An independent claim is included for corresponding apparatus, consisting of a reaction vessel (1), a tightly closable lid (3), a base (2), a heating coil (8) above the base within the vessel, a supporting grid (9) above the heating coil and excess pressure and reduced pressure valves (6, 7) for the vessel.

Description

The The invention relates to a device for industrial production from peeled Potatoes or similar fruit and vegetables with extended shelf life through conservation.

Of the Consumption of table potatoes in Germany is approx. 6 Million tons a year, of which less than freshly peeled potatoes and a much smaller portion than pre-cooked potatoes. These Potatoes are used in kitchen equipment processed, the short-term strongly fluctuating quantities of ready need boiled potatoes or Need to catch peaks. The costs are very high to compensate for this need. For cost reasons are therefore for a minimum sales so far only freshly peeled potatoes in use.

Of the relatively low sales of potato canned food is exclusively due the too high price of their production. With the traditional technology However, no price reduction is possible. It is expected that the proportion of shelled and pre-cooked potatoes at cheaper Sales prices will continue to rise sharply.

[State of the art]

• 1. In der Praxis werden frisch geschälte Kartoffeln in spezielle hitzeresistente Kunststoffsäcke abgefüllt. In die Säcke wird etwas Wasser gegeben und mittels Vakuumverschluss wird erreicht, dass sich keine Luft in der Verpackung befindet.
• 2. Diese Abpackungen durchlaufen danach eine ständig mit kochendem Wasser gefüllte Rinne. Dort erfolgt die Sterilisierung bei gleichzeitigem Garen. Durch Verdunstung und technologisch bedingten Verlust wird Wasser verbraucht. Durch die Anwendung einer Temperatur von 100°C bei Umgebungsdruck reichen bei einzelnen Kartoffeln reaktionskinetisch 18 Minuten aus, um den optimalen Garzustand zu erreichen. Bei größeren Kartoffelmengen, wie in der Praxis üblich, verschlechtert sich die Wärmeübertragung (Kunststoffsack, ruhendes Wasser in der Verpackung). Dadurch bedingt verlängert sich der Garprozess auf bis zu 40 Minuten und darüber. Die technisch bedingten Wärmeverluste erhöhen sich, da die äußeren Schichten länger thermisch behandelt werden als im Kern. Es kommt zu unterschiedlichen Garqualitäten. Diese können nur durch den Einsatz „festkochender" Sorten gering gehalten werden.
• 3. Anschließend werden diese sterilen Abpackungen in fließendem kalten Wasser im Gegenstromverfahren abgekühlt, um ein Nachgaren zu verhindern. Dieser Effekt stellt sich ein, da bei Raumtemperatur die Abkühlung im Kern zu lange dauern würde, was zu einem Qualitätsverlust führt. Das durch den Abkühlprozess erhaltene Warmwasser wird in den Vorfluter gegeben und die enthaltene Abwärme wird nicht genutzt. Eine technische Kühlung des Wassers ist aus Kostengründen bisher nicht üblich.

The previous preservation of potatoes traditionally takes place in three process stages.

• 1. In practice, freshly peeled potatoes are bottled in special heat-resistant plastic bags. Some water is added to the bags and the vacuum seal ensures that there is no air in the packaging.
• 2. These packages then go through a constantly filled with boiling water channel. There the sterilization takes place with simultaneous cooking. Evaporation and technological loss mean that water is consumed. By applying a temperature of 100 ° C at ambient pressure for individual potatoes reaction kinetically sufficient 18 minutes to achieve the optimum state of cooking. For larger amounts of potatoes, as usual in practice, the heat transfer deteriorates (plastic bag, dormant water in the package). As a result, the cooking process is extended to up to 40 minutes and more. The heat losses due to technical reasons increase because the outer layers are thermally treated for longer than in the core. It comes to different cooking qualities. These can be kept low only by the use of "festkochender" varieties.
• 3. Thereafter, these sterile packages are cooled in flowing cold water in countercurrent, to prevent Nachgaren. This effect occurs because at room temperature the cooling in the core would take too long, resulting in a loss of quality. The hot water obtained by the cooling process is added to the receiving water and the waste heat is not used. A technical cooling of the water is not common for cost reasons.

The Potato canned food can economically produced only in large quantities according to these methods, because with this technology, the cost is inversely proportional to Throughput are.

By a missing or insufficient Isolation of all existing systems in use arise Energy losses through evaporation, evaporation and radiation.

The Traditional production of preserved potatoes does not match more the current technological Options.

For the provision the peeled Potatoes become available technologies like peeling machines and packaging machines used.

Known solutions assume that aseptic filling in this area only with unreasonably high effort possible is. Besides, they are the capacities the corresponding plants very high, since there is no automatic process control and therefore the effectiveness only over size Quantities is reached. Thus, the use of such systems is only to a few large producers limited, that too over the necessary big one Paragraph. (That implies a wide distribution radius) The plants were designed and built as the share of energy costs to the Costs negligible was small. Therefore, the specific energy consumption is very high.

It At the moment, there are no plants that are designed for smaller capacities are and have a low specific energy consumption.

OBJECT OF THE INVENTION

task The invention is an apparatus for industrial production of peeled potatoes or similar fruit and vegetables with extended To provide durability in which even smaller quantities are economical can be produced reasonably, reduces energy losses, reduces overall energy consumption as well as quality losses diminished and a longer one Durability allows becomes. Furthermore the equipment use is to be reduced and those incurred in the process control reaction kinetic values are attributed to the process.

The Task is solved with the features of the first protection claim. advantageous Further developments and embodiments are the subject of the dependent claims.

The Device consists of a preferably cylindrical reaction vessel as a base body with a bottom floor and an upper opening.

The Reaction vessel serves for receiving the reaction mixture, for. As potatoes or the like Fruit and vegetables, and water.

The upper opening is closed by a lid. By a suitable pressure-tight closure technology and wall thickness of the reaction vessel is it is possible in the vessel an overpressure and to generate a negative pressure. For pressure equalization and for safety reasons is on the reaction vessel an over- and arranged a vacuum valve.

Of the Soil is flat like a pot, but it can also be conical or arched down accomplished be. In the lower part of the reaction vessel is located above the Floor a heating coil for the energy supply.

The Heating spiral is protected against direct contact by a protective grid protected with the reaction mixture. At the same time, the protective grid is at such a height above the Floor arranged that for a sufficiently high vapor pressure necessary amount of water not with the Reaction in contact comes.

In the height of the protective grid is therefore expediently also the inlet nozzle for the feed of the water.

to Avoidance of energy loss is the total reaction vessel optimally thermally insulated by the choice of material and / or coating.

At the lowest point in the bottom of the reaction vessel is a drain valve for the Cooking water, which is preferably operated remotely. This is the hot water after the cooking process in a arranged below the reaction vessel Cooking water collecting tank derived.

There while the cooking process starch, cell and ingredient ingredients in the cooking water must pass from technological and hygienic reasons The cooking water is filtered before it is also in the well-insulated Cooking water collecting tank flows.

through a pump can then this water via a pipe and / or hose recycled back into the reaction vessel and for another Cooking process can be used. This eliminates the cooling phase for this water and the next process starts with preheated Water. At the same time, the energy required for the next cooking process is reduced.

The Return of the Cooking water is over the inlet nozzle, at the same time if necessary, the fresh water filled will, either for the first filling or to compensate for water losses during the cooking process.

Around the reaction vessel easy to be able to empty this is stored so that it can be swiveled up to 180 °.

With the device according to the invention the following method is realized.

at open Lid will be peeled potatoes or another corresponding good and water filled in the reaction vessel. After that will the lid is placed and the reaction vessel by screwing, locking or similar pressure-tight locked.

It is possible, too, that the lid closes by its own weight, the reaction vessel and thus even fulfilled the function of a pressure relief valve.

Subsequently, will Energy over supplied to the heating element. This is located in the water and guarantees along with a Temperature control a minimum of energy.

By Heating the water, an overpressure is generated in the reaction vessel, whereby the Cooking time only a fraction over traditional methods is. Leading also to a considerable reduction of energy consumption.

To In the cooking process, the cooking water is filtered and in the isolated Cooking water collecting tank drained. This water is for the next Reused cooking process. To speed up this process step can the pressure relief valve remain closed until the cooking water is completely emptied. After that becomes the pressure relief valve open. It quickly adjusts to ambient pressure. Through this fast Pressure drop is already a temperature drop in the reaction vessel.

Then negative pressure is applied in the reaction vessel. By lowering the evaporation temperature and the thus beginning Cool water evaporation the cooked potatoes continue.

The Temperature is lowered so far that no Nachgaren take place can. At the same time the temperature is still so high that during the filling process no contamination possible is.

To Termination of this process is again set to ambient pressure. The lid is opened and the reaction vessel is pivoted. The potatoes are handed over to an aseptic packing station and subsequently packed up.

To the packaging can If necessary, the potatoes can be continued by air, water or technical cooling chilled become.

In continuation of the inventive idea offers a tandem arrangement consisting of two reaction vessels.

The Operation is based on two alternating stages.

step 1 includes filling, Closing as well the cooking and printing phase. It will be completed with the handover of the cooking water.

The Stage 2 involves cooling by means of vacuum and opening. It will be completed with the handover of the treated goods to the packaging station.

In this case could the cooking water collector omitted, because the hot Sewage directly to the next Reaction vessel is supplied.

[Examples]

At Hand of drawings become embodiments closer to the invention explained.

It demonstrate:

1 A device for preserving potatoes,

2 A device for preserving potatoes with two reaction vessels.

The reaction vessel 1 exists according to 1 from a cylindrical, pot-shaped base body with a bottom arranged bottom 2 and an upper, through a lid 3 pressure-resistant closable opening.

The floor 2 is executed in this arrangement hemispherical curved downward.

The lid 3 is by means of a seal 4 and locking clips 5 firmly on the reaction vessel 1 pressed. cover 3 and reaction vessel 1 are chosen in their material and wall thickness so that a necessary for the execution of the process pressure and negative pressure can be generated. For pressure equalization and safety reasons are in the lid 3 an over- 6 and a vacuum valve 7 appropriate.

The floor 2 is curved downwards. Above the ground 2 is a necessary for the energy supply heating coil 8th , She is through a protective grid 9 against direct contact with the reaction mixture 10 , here shown as potatoes, protected.

The protective grid 9 is also at such a height above the ground 2 arranged that one necessary for a sufficiently high vapor pressure, in the lower part of the reaction vessel 1 filled amount of water 11 not with the potatoes 10 comes into contact.

In the height of the protective grid is an inlet nozzle 12 for the supply of water 11 ,

The reaction vessel 1 stands on a cooking water container 13 , which is also designed as well insulated as possible.

At the lowest point of the reaction vessel 1 is a closable drain valve 14 for draining the cooking water 11 arranged. Conveniently, the reaction vessel 1 only via a small opening with the cooking water collecting container 13 connected to the heat losses when separating the reaction vessel 1 from the cooking water container 13 to keep low. The reaction vessel 1 can either have a sealing flange 15 or via a in the cooking water collection container 13 projecting piece of pipe with the cooking water collecting container 13 get connected.

The opening in the cooking water collector 13 after lifting off the reaction vessel 1 can also be designed sealing.

For catching in the cooking water 11 containing starch, cell and ingredient ingredients is between the reaction vessel 1 and the cooking water catcher 13 a filter 16 arranged.

Via a return line 17 is by means of a pump 18 the water 11 back into the reaction vessel 1 recycled.

For emptying, the reaction vessel 1 from the cooking water container 13 lifted, the lid 3 unfolded and the whole vessel 1 around an axle (not shown) pivoted.

About the inlet nozzle 12 will both fresh water 19 (for the first filling and to compensate for cooking losses) as well as the water 11 from the cooking water container 13 filled.

In 2 is a device for preserving potatoes 10 with two reaction vessels 1.1 and 1.2 shown. This tandem system uses two identical reaction vessels 1.1 and 1.2 according to the reaction vessel 1 to 1 ,

While a reaction vessel 1 is in the cooking and pressure phase, the second works in the cooling and vacuum phase. On the cooking water container 13 can be dispensed with in this arrangement, since the hot water 11 directly to the other reaction vessel 1 is supplied.

From the one reaction vessel 1.1 leads from the drain valve 14 one pipeline each 17 to the inlet nozzle 12 of the other reaction vessel 1.2 , The for filtering the cooking water 11 necessary filters 16 is like in 1 directly after the drain valve 14 arranged.

1

reaction vessel

1.1

first Reaction vessel in tandem arrangement

1.2

second Reaction vessel in tandem arrangement

2

ground

3

cover

4

poetry

5

locking clips

6

Pressure relief valve

7

Vacuum valve

8th

heating coil

9

Shelf guide, guard

10

reaction material, potatoes

11

water

12

Water supply, inlet port

13

Cooking water collecting tank

14

drain valve

15

sealing flange

16

filter

17

Return line

18

pump

19

Fresh water supply

Claims (13)

Apparatus for the industrial production of peeled potatoes or similar fruit and vegetables with extended shelf life consisting of - a reaction vessel ( 1 ), - a reaction vessel ( 1 ) tight-fitting lid ( 3 ), - a floor ( 2 ), - one above the ground ( 2 ) within the vessel ( 1 ) arranged heating coil ( 8th ) and - one above the heating coil ( 8th ) arranged support grid ( 9 ), - one on the reaction vessel ( 1 ) arranged over ( 6 ) and vacuum valve ( 7 ) and - one at the lowest point of the soil ( 2 ) arranged drain valve ( 14 ) with downstream filter ( 16 ). Apparatus according to claim 7, characterized in that the over- ( 6 ) and the vacuum valve ( 7 ) in the lid ( 3 ) is arranged. Device according to claim 8, characterized in that the lid ( 3 ) by means of one or more closures ( 5 ) is closed pressure-tight. Device according to claim 7, characterized in that the lid ( 3 ) has a weight corresponding to the maximum allowable pressure. Apparatus according to claim 7, characterized in that the reaction vessel ( 1 ) an inlet nozzle ( 12 ) for water ( 11 ) is arranged. Apparatus according to claim 7, characterized in that the reaction vessel ( 1 ) cylindrical and the bottom ( 2 ) is circular, conical or curved downwards. Apparatus according to claim 7, characterized in that the below the reaction vessel ( 1 ) and the drain valve ( 14 ) a Kochwasserauffangbehälter ( 13 ) is arranged. Apparatus according to claim 7, characterized in that the cooking water collecting container ( 13 ) to the reaction vessel ( 1 ) a line ( 17 ) with a pump ( 18 ) for returning the collected cooking water ( 11 ) is arranged. Apparatus according to claim 7, characterized in that for determining the water losses in the reaction vessel ( 1 ) or in the cooking water collecting container ( 13 ) A level gauge is arranged. Apparatus according to claim 7, characterized in that the reaction vessel ( 1 ) A vacuum pump is arranged. Apparatus according to claim 7, characterized in that the reaction vessel ( 1 ) about a horizontal axis, through the center of gravity of the reaction vessel ( 1 ) is designed pivotally. Device according to claims 7, 13 and 14, characterized in that the reaction vessel ( 1 ), the Kochwasserauffangbehälter ( 13 ) and the return line ( 17 ) is optimally thermally insulated. Apparatus according to claim 7, characterized in that two identical reaction vessels ( 1.1 . 1.2 ) while saving the cooking water collecting container ( 13 ) are interconnected.