FR2735748A1 - METHOD AND INSTALLATION OF ASEPTIC PACKAGING OF FRESH FOODSTUFFS IN SOFT OR RIGID PACKAGES - Google Patents

Abstract

The installation involves, after pre-washing, peeling and cutting the vegetables, asepticising them in a first sealed caisson (10,11) by a continuous current of superheated steam for between 1 and 15 minutes. The steam is at a temperature between 105 and 140 deg. and a pressure between 0.5 and 1 bar. The products are then transferred into a second sealed caisson (20,21), containing the steam coming from the first caisson, and directed to the next stage or to a recovery tray. Inside a third caisson (30,32) the products are transferred towards a first sealed chamber (40) and injected with carbonic gas or helium. The products are weighed and a determined weight is placed in flexible or rigid unclosed packages (45). The packages are transferred successively into a second sealed chamber (60). In the second chamber the packages are injected with steam whilst under vacuum. Steam injection is stopped and a mixture of between 40% and 90% nitrogen, between 60% and 10% carbonic gas and between 1% and 10% oxygen is injected and the packages sealed. At exit from the chamber the packages are cooled to about 2 deg.

Description

The present invention relates to a method and an installation of

  aseptic packaging of fresh food products, such as fruit or vegetables and preferably potatoes, in flexible or rigid packages. Methods for packaging food products in flexible packaging

low capacity and put under vacuum.

  However, these processes for packaging food products in vacuum packs have a major drawback which lies in the fact that, to effect the temperature transfer through the package in order to sterilize the product, the bags are introduced into an autoclave and are subjected to a pressure of 4 to 5 bar and a temperature of 125

at 135 degrees C.

  At this pressure, food products

  res, such as potatoes, are subject to significant stresses which cause the peripheral cells of the product to burst, thus releasing the starch

  and facilitating the agglomeration of products between them.

  In the packages thus treated, the products are in the form of a mass that the housewife is obliged to wash to detach the products.

between them.

  In addition, the heat transfer from the outside of the wall of the flexible packaging to the product, causes overcooking of the product located in

contact of the flexible packaging.

  Finally, the duration and intensity of treatment

  generate Maillard reactions that require

  both the systematic use of high-dose additives and

  especially the use of metabisulphite.

  The object of the invention is to avoid the inconveniences

  previously mentioned by proposing a process and a facility for aseptic packaging fresh food products that can keep, under pressure of neutral gas, treated products o all organoleptic qualities are preserved as for example vitamins, minerals and sugars. The subject of the invention is therefore a process for the aseptic packaging of fresh food products, such as for example fruits or vegetables in flexible or rigid packs, characterized in that, after a pre-washing and possibly a peeling and cutting of the products: a desiccation of the products is carried out inside a first seal chamber by a stream of vapor at a temperature of between 105 and 140 ° C. at a pressure of between 0.5 and 1 bar and for 1 to 15 minutes; the products are transferred inside a second watertight box containing steam from the first well to direct these products to the following stages or to a recovery tank, - it is carried out inside a third box the transfer of the products to a first sealed enclosure and is injected into this third box

  and in this first sealed chamber carbon gas

  that, helium or others, is carried in said first sealed chamber weighing or dosing of the products and is deposited a fixed weight of products in the flexible or rigid unclosed packaging, is transferred successively into a second enclosure waterproof flexible or rigid packaging, filled with products, - in this second sealed chamber and for each package, it is carried out under vacuum of said packages with steam injection during the evacuation, stopping the injection of steam, then the under vacuum, a mixture consisting of 40 to 90% nitrogen and 60 to 10% carbon dioxide is injected and the injection is stopped.

  of nitrogen and carbon dioxide, and 1 to 10% of oxy-

  gene and seal the flexible packaging or are sealed rigid packaging - and, at the outlet of said sealed enclosure, is cooled to about 2 C packaging

filled and sealed or crimped.

  According to another characteristic of the invention

  Before the products are sterilized, the products are washed in a water bath heated to a temperature greater than or equal to 60 ° C. for 1 to 5 hours.

  minutes and these products are cooled to a temperature of

  ture between 15 and 20 C for 4 to 10 minutes

according to the size of the products.

  The subject of the invention is also an aseptic packaging plant for fresh food products, for carrying out the process mentioned above, characterized in that it comprises: - means of prewashing and possibly peeling and cutting products, - a sealed member for transporting the products in a first sealed box comprising adjustable means for holding the products in said cooker for a variable time of between 1 and 15 minutes, means for injecting steam at a pressure between 0.5 and 1 bar, means for superheating the steam at a temperature of between 105 and 140 ° C. and means for putting this vapor into continuous circulation; means for transferring the products comprising a second watertight container connected to the first box and containing the steam from said first box, said second box being provided with a conveyor products to a first lock of product recovery, either to a second lock of transfer of products to a transport member of these products, disposed in a box supplied with carbon dioxide, helium or the like, - a first sealed enclosure comprising means for weighing or dosing products and means for depositing a fixed weight of products in flexible or rigid packaging, said enclosure being supplied with carbon dioxide, helium or the like, means for transferring flexible or rigid packaging, filled with products in a second sealed enclosure comprising means for evacuating the packages and for injecting steam during evacuation, means for injecting a mixture consisting of 40 to 90% nitrogen and 60 to 10% carbon dioxide and injection of oxygen in a proportion of between 1 and 10% and means of sealing the flexible packaging or crimping of rigid packaging, and cooling means to approximately

  2 C of said packages filled and sealed or crimped.

  According to other features of the invention,

  the installation comprises, between the means for prewashing and the means of transporting the products to the first box, means for washing the products in a water bath heated to a temperature greater than or equal to 60 ° C. for 1 to 5 minutes and cooling means of said products at a temperature between 15 and 20 C for 4 to 10 minutes, depending on the size of the products, - the sealing member is formed by a metal elevator belt whose lower part is immersed in a bath of cold water, said cold water bath constituting a hydraulic seal for the vapor contained in the first box, - the adjustable means of residence of the products in the first box are formed by a horizontal conveyor with meshes mounted on a mobile support for extracting said conveyor from the first well, - the superheating means of the steam in the first well are formed by a coil fed with high steam pressure disposed below the horizontal conveyor mesh and separated therefrom by a metal plate, - the means for the continuous circulation of the steam in the first box are formed by the

  minus a fan placed near the food

  products in said first box.

  The characteristics and advantages of the invention

  will appear in the course of the description which will

  follow, given solely by way of example and with reference to the single appended figure which schematically represents a packaging installation

  aseptic fresh food products.

  In what follows, the description will be made

  for the aseptic packaging of food products

  potatoes, the process and the plant according to the invention being applicable to other fresh food products and in a manner

  general fruit and vegetable.

  Moreover, in this description, the

  packaging of food products will consist of flexible packaging made of plastic film, complex or aluminized complex film or other, other

  flexible or rigid packaging that can be used.

  After a preparation according to processes commonly used in canning, namely the prewashing, peeling, cutting and trimming of the potatoes, they are washed for a variable duration of 1 to 5 minutes in a water bath heated to a temperature greater than or equal to 60 C. Following this operation, the potatoes are cooled to a temperature between -20 C for 4 to 10 minutes depending on the size of the products.

  Then, the potatoes are transported

  eg by a hydraulic circuit or any other means of supply in the installation according to

  the invention shown in the single figure.

  This installation first comprises a sealed member 1 for transporting the potatoes which are discharged through a conduit 2 into a tray 3 filled with

of cold water.

  This sealing member 1 for transport is constituted by a metal elevator belt 4 arranged

in a box 5.

  This box 5 and the elevator belt 4 are partially immersed in the cold water bath so that it forms a hydraulic seal

  waterproof, as will be seen later.

  Tray 3 has on its back wall a

port 6 too full of water.

  The potatoes are poured through the conduit 2 into the water contained in the tank 3 and are conveyed via the elevator belt 4 in a device generally designated by the reference 10. This apparatus 10 comprises a metal box 11 of orthogonal or circular section closed to

  one end by a metal door 12.

  The box 11 also has at its upper part an opening 13 above which opens the elevator belt 4 to dump the apples

in the box 11.

  The casing 11 comprises: - adjustable means of residence of the potatoes for a variable time of between 1 and 15 minutes, - steam injection means at a pressure between 0.5 and 1 bar, means of overheating steam at a temperature of between 105 and 140 ° C, and means for putting into circulation

continue this steam.

  The adjustable means of stay of the potatoes in the box 11 are formed by a horizontal conveyor 14 with meshes mounted on a movable support, not shown, for the extraction of said conveyor 14 by the

  door 12 of the box 11 for cleaning.

  One end of the conveyor 14 is disposed below the opening 13 while its opposite end is disposed above an opening 15 for the discharge of the potatoes after their passage through

the device 10.

  The steam injection means in the box 11 are formed by a tube 16 whose end opens at the base of the box 11 and below the

conveyor 14.

  The means for overheating the steam injected by the tube 16 into the box 11 are formed by a coil 17 supplied with high pressure steam, for example at 8 bar, to raise the steam to a temperature

between 105 and 140 C.

  The coil 17 is disposed below the conveyor 14 and is separated therefrom by a metal plate 18 so that the steam injected by

  the tube 16 inside the box 11 circulates against

  current in relation to the direction of transport of the apples

land by the conveyor 14.

  In order to accelerate the circulation of the steam in the box 11 and to homogenize the heat exchange between this steam and the potatoes deposited on the conveyor 14, the box 11 is equipped with means for the continuous circulation of this steam. which consist of at least one fan 19 placed inside the box 11 near the opening 13

  spilling potatoes on the conveyor 14.

  The fan 19, driven by a motor 19a disposed outside the casing 11, sucks the steam at the outlet of the conveyor 14 and returns it to the coil 17 thus obtaining a uniformity

  the temperature in the box 11.

  The low pressure steam arrivals through the tube 16 and high pressure in the coil 17 are electronically regulated according to a program

determined.

  The tightness of the box 11 and the transport member 1 is ensured by the water contained in the tank 3 so that the steam injected into the box 11 does not

can not escape.

  The potatoes dumped by the elevator belt 4 into the opening 13 of the box 11 fall on the conveyor 14 and are sanitized by the superheated steam at a temperature between

and 140 C.

  The residence time of the products inside the box 11 is variable depending on the type of products and is generally between 1 and 15 minutes. The treated potatoes are discharged through the outlet orifice 15 into transfer means 20. The transfer means 20 for the potatoes comprise a watertight box 21 connected to the box 11 through the orifice 15 and containing steam from of said box 11. The box 21 is provided with a conveyor

  horizontal 22 disposed below the opening 15.

  This horizontal conveyor 22 is driven in one direction or the other so as to discharge the potatoes either in a first lock 23 for the

  recovery of potatoes in a non-reputable container

  placed in a second lock 26 for the transfer of these potatoes into the next part of the installation. The watertight box 21 is directly subjected to the vapor pressure coming from the box 11. Its sealing with the superheated steam is ensured by

the two locks 23 and 26.

  The first lock 23 comprises two sealed flaps 24 and 25 which open alternately to let the potatoes to the recovery tank. Opening or closing shutters

  24 and 25 is provided by pneumatic cylinders.

  24a and 25a respectively.

  The two pneumatic cylinders 24a and 25a are controlled by a relay, not shown, allowing for example the flap 24 to open to let the potatoes, while the flap 25 is closed. Then after a programmed time, the flap 25 closes to allow, after a moment of waiting, the steam contained between the two flaps 24 and 25 to escape through an extraction duct 21a and the flap 25 opens. for

  let the potatoes pass to the recovery tank.

  The second lock 26 also comprises two watertight shutters, respectively 27 and 28, which open alternately to let the potatoes pass to the next part of the installation, as it is

will see later.

  The opening or closing of the two flaps 27 and 28 is performed by two pneumatic cylinders or

  respectively 27a and 28a.

  The two cylinders 27a and 28a are controlled by a relay, not shown, allowing for example the flap 27 to open to let the potatoes, while the flap 28 is closed. Then after a programmed time, the flap 27 closes to allow, after a moment of waiting, the steam contained between the two flaps 27 and 28 to escape through the extraction duct 21a and the flap 28 opens. to leave

pass the potatoes.

  The potatoes are, at the exit of the lock 26, discharged to a transport member 30 of these potatoes in a first sealed enclosure

40.

  The transport member 30 of the potatoes is constituted by a conveyor lift 31 with meshes,

arranged in a box 32.

  The casing 32 is equipped with a suction plug

  ration 33 of the fluent vapor escaping from the lock

26 and steaming potatoes.

  In addition, the box 32 is provided with a pipe 34 of possible injection of carbon dioxide, helium or other for better conservation of

potatoes.

  These potatoes transported by the elevator conveyor 31 flow into the sealed enclosure 40 which comprises means 41 for weighing or

dosage of said potatoes.

  A supplement of carbon dioxide or other is optionally injected into the sealed enclosure 40 by the

  piping 42 whose excess is sucked by the depres-

prevailing in the caisson 32.

  Thus, the chamber 40 is kept under a controlled atmosphere, which makes it possible to avoid, by this

  backpressure, the return of air and any micro-

  organization. After weighing or dosing, the potatoes fall into the cells of the packages 45 which consist for example of flexible trays formed

by a conditioner 50.

  For this purpose, the packaging machine 50 has a thermoforming station, not shown, which forms the packages 45 from a film reel 46

  barrier complex PP-PA or others.

  The sterilization of the film is ensured during the thermoforming which is carried out at a temperature of the order

1400 C after preheating.

  The packages 45 are therefore filled automatically.

  by the weighing or dosing means 41 which discharge the potatoes as and when

packaging scrolling 45.

  The packages 45 thus filled are transferred

  res by a conveyor belt 47 in a second sealed enclosure 60 in which the packages 45 are sealed by an upper film of the same material as the film forming the bottom of the packages 45 and unrolled from

a coil 61.

  Moreover, in this sealed enclosure 60, before the closure of the packages 45, various operations

  are carried out in order to compensate for any risk of developing

  anaerobic bacteria and in particular the

Clostridium botulinum.

  These operations consist in evacuating the packages 45 placed in the sealed enclosure 60 and injecting steam during the evacuation so as to sanitize the packaging and carry out a supplementary sanitization of safety of the potatoes. After stopping the steam injection and then stopping the evacuation, a mixture consisting of 60 to 90% nitrogen and 40 to 10% carbon dioxide is

  injected into the sealed enclosure 60.

  Preferably, the mixture consists of

  % nitrogen and 10% carbon dioxide.

  After stopping the injection of this mixture into the sealed chamber 60, oxygen is injected into this sealed enclosure 60 in a proportion of

  between 1 and 10% and preferably equal to 1%.

  Then the top film is sealed and at the

  out of the sealed enclosure 60, the solder packing

  is controlled and these packages are coded and a

  Best-before date is printed.

  The packages are then cooled to a

  temperature of the order of 2 C and put in cardboard.

  The method and the installation according to the invention

  can be processed without additives, fresh food products, such as fruits or vegetables with a deadline for use

optimal for at least three weeks.

  In addition, all the organoleptic qualities of the product are preserved as well as for example the

  vitamins, minerals and sugars.

  Moreover, the products thus prepared by the process according to the invention are not in contact with

  juicing water in which they gradually lose

  by dissolution, some of their flavor, their

  aroma and their nutritional principle.

Claims (11)

  1. A process for the aseptic packaging of fresh food products, such as fruit or vegetables, in flexible or rigid packages, characterized in that, after prewashing and possibly peeling and cutting the products: inside a first watertight case (10, 11) a sanitization of the products by a continuous stream of superheated steam at a temperature of between 105 and 140 ° C. at a pressure of between 0.5 and 1 bar for 1 to 15 minutes. minutes, - the products are transferred to   the inside of a second watertight box (20, 21) containing   steam from the first well (10, 11) for directing these products to the next steps or to a collection tank, - the transfer of the products to a third box (30, 32) is effected. a first sealed enclosure (40) and is injected into this third box (30, 32) and in this first sealed chamber (40) carbon dioxide, helium or the like, - is carried in said first sealed chamber (40) weighing or dosing the products and depositing a specific weight of products in the packages (45) flexible or rigid unclosed, - is transferred successively in a second sealed chamber (60) packaging (45) flexible or rigid, filled with products, - in this second sealed enclosure (60) and for each package (45), the packaging (45) is vacuum-evacuated with steam injection during evacuation, the steam injection is stopped and the vacuum is then evacuated. , we inject a mixture composed of 40 to 90% of nitrogen and 60 to 10% of carbon dioxide, the injection of nitrogen and carbon dioxide is stopped and 1 to 10% of oxygen is injected and the flexible packaging is sealed or crimped. the rigid packs, and, at the outlet of said sealed enclosure (60), the filled packages are cooled to around 2 ° C. and sealed or crimped.   2. Method according to claim 1, characterized   in that before washing the products, washing said products in a water bath heated to a temperature greater than or equal to 60 C for 1 to 5 minutes and cooling said products to a temperature of between 15 and 20 C during 4 to   minutes depending on the size of the products.   3. Aseptic packaging system for fresh food products, for the implementation   process according to claims 1 and 2, characterized   in that it comprises: - means for prewashing and possibly peeling and cutting the products, - a sealed member (1) for transporting the products in a first sealed box (10, 11) comprising adjustable means (14). ) of residence of the products in said first box (10, 11) for a variable time of between 1 and 15 minutes, means (16) for injecting steam at a pressure of between 0.5 and 1 bar, means ( 17) superheating of the steam at a temperature between 105 and 140 C and means (19) for the continuous circulation of this steam, - means (20) for transferring the products comprising a second watertight case (21) connected at the first watertight case (10, 11) and containing the vapor coming from said first box (10, 11), said second box (21) being provided with a conveyor (22) of the products either towards a first lock (23) of recovery products, either to a second lock (26) for the transfer of products to a transport member (30) for these products, disposed in a box (32) fed with carbon dioxide, helium or the like, - a first sealed enclosure (40) comprising means (41) for weighing or dosing the products and means for depositing a fixed weight of products in the flexible or rigid packagings (45), said sealed enclosure (40) being supplied with carbon dioxide, helium or the like; means (47) for transferring the flexible packaging or rigid, filled with products in a second sealed enclosure (60) comprising means for evacuating the packages (45) and for injecting steam during the evacuation, means for injecting a mixture consisting of 40 to 90% nitrogen and 60 to 10% carbon dioxide and oxygen injection in a proportion of between 1 and 10% and means for sealing flexible packaging (45) or crimping of rigid packaging, - and cooling means to about   2 C of said packages (45) filled and sealed or crimped.   4. Installation according to claim 3, characterized in that it comprises, between the pre-washing means and the means for transporting the products to the first box (10, 11), means for washing the products in a water bath heated to a temperature greater than or equal to 60 C for 1 to 5 minutes and   means for cooling said products to a temperature of   ture between 15 and 20 C for 4 to 10 minutes according to the size of the products.   5. Installation according to claim 3, characterized in that the sealing member (1) is formed by a conveyor belt (4) metal whose lower part is immersed in a bath of cold water, said water bath cold forming a hydraulic seal   for the steam contained in the first box (10, 11).   6. Installation according to claim 3, characterized in that the adjustable means of residence of the products in the first box (10, 11) are formed by a horizontal conveyor (14) mesh mounted on a movable support for the extraction of said conveyor of first box (11).   7. Installation according to claim 3, characterized in that the superheating means of the steam in the first box (10, 11) are formed by a coil (17) supplied with high pressure steam, arranged below the horizontal conveyor ( 14) Mesh   and separated therefrom by a metal plate (18).   8. Installation according to claim 3, characterized in that the means for the continuous circulation of the steam in the first box (10, 11) are formed by at least one fan (19) disposed near the feed of the products. in said first box (10, 11).   9. Installation according to claim 3, characterized in that each lock (23, 26) is formed of two flaps (24, 25, 27, 28) sealed and pivoting alternately. 10. Installation according to claim 9, characterized in that the opening or closing of each flap (24, 25, 27, 28) is controlled by a jack (24a, 25a, 27a, 28a).   11. Installation according to claim 3, characterized in that the product transport member between the transfer means (20) and the first sealed chamber (40) are formed by a conveyor elevator (31) with mesh.