WO2000013988A1

WO2000013988A1 - Packaging for roasted and/or slightly roasted coffee and method for packaging roasted and/or slightly roasted coffee

Info

Publication number: WO2000013988A1
Application number: PCT/EP1999/005945
Authority: WO
Inventors: Hans-Werner Meixner; Ingo Karnitzschky; Stefan BÖS
Original assignee: Pi-Vac Gmbh Verpackungssysteme
Priority date: 1998-09-07
Filing date: 1999-08-13
Publication date: 2000-03-16
Also published as: AU5516199A; DE19840713A1

Abstract

The invention relates to a packaging for roasted and/or slightly roasted coffee, said packaging exhibiting at least in part at least one expandable plastic film. In addition, the inventive packaging is designed in such a way that internal pressure generated by the gas released by the coffee is smaller than a burst pressure of the packaging and/or a closure of said packaging. The invention also relates to a method for conditioning coffee without intermediate storage designed for release of carbon dioxide (CO2). The packaging is sealed immediately after it has been filled with roasted coffee.

Description

Packaging for roasted and / or roasted

Coffee and method for packaging roasted and / or roasted coffee

description

The invention relates to a packaging for roasted and / or roasted coffee in ground or unground form and a method for packaging roasted and / or roasted coffee in ground and / or unground form.

In terms of packaging technology, roasted coffee is characterized by three main properties:

- The roasted coffee emits, caused by the roasting process, carbon dioxide (C0 ₂ ) that comes from packaging either directly in the packaging process in substantial quantities must be withdrawn (vacuum packaging) or must be able to escape through the packaging material.

- The roasted coffee absorbs oxygen (0 ₂ ) from the ambient air, which, with the fats contained in the coffee, leads to malodorous fatty acid derivatives.

- The roasted coffee loses aromas.

According to the state of the art (Bernhard Rothfos "Coffee

- The consumption "- GORDIAN-Max Rieck GmbH, Hamburg, 1984 (ISBN 3-920391-07-1)) for packaging roasted coffee with regard to the above-mentioned main features, either packaging that withstands a certain overpressure without deformation, or Packaging that can let an internal overpressure escape - either through the material (limited gas permeability of the packaging material, e.g. paper packaging, from the inside to the outside) or through a valve that is reliably return-free under all transport, storage and so on conditions (Rothfos op. cit., page 219).

Rothfos (op. Cit.) States that the gas release of the roasted coffee for a long period after roasting makes the quality-preserving packaging of coffee extremely difficult. Above all, it restricts the packaging of unground roasted coffee in gas-tight, low-oxygen packs and requires certain pretreatments for the packaging of ground coffee in such packs. The gas release of roasted coffee is to a certain extent dependent on both the variety and the degree of roasting. Already during roasting, the CO ₂ gas formation creates a considerable overpressure in the coffee bean. This overpressure also loosens the bean structure during roasting, for example. Is measured after roasting the C0 ₂ -Druckent- development in roasted coffee, it is found that when whole beans after 24 hours only about 15% of the still trapped C0 ₂ have resigned in coarsely ground beans but already 60% ground with fine Beans already 80%. Expressed in hours, whole beans released their C0 ₂ after reaching the pressure equilibrium state compared to the external pressure acting on them (meaning the natural external atmosphere) after around 2,580 hours (almost four months), coarsely ground beans after around 1,000 hours, finely ground Beans after about 400 hours (Rothfos op. Cit., Pages 224 and 225).

Because of this basis, various coffee packaging now belongs to the state of the art.

1. Coffee packaging with overpressure

A package that can withstand the resulting overpressure without deformation is known from EP 0 350 128 B1. According to this document, an attempt is made to specify packaging that can withstand a relatively high internal pressure.

This packaging, which belongs to the prior art, has the disadvantage that, on the one hand, the packaging is very complex and expensive to manufacture, since, as already stated, the packaging has to withstand a relatively high internal pressure. In addition, this prior art packaging has the disadvantage that a valve closure is provided, which is also complex to manufacture and costly. The valve closure must be designed so that a very large amount of gas (0.1 to 2 liters) can escape in less than a second within a very short time (EP 0 350 128 B1, page 9, lines 10 to 11). In addition, when the gas escapes, no coffee, in particular coffee powder, must escape from the packaging.

Gas permeable packaging

For the packaging of whole beans, mainly material is used, which consists of greaseproof paper. The barrier properties of this material against gases and aromas are minimal, so that only a relatively short shelf life is achieved. Usually, the goods are therefore re-sorted weekly at retailers and packages that have been in storage for longer periods are discarded. The grinding takes place at the trade or at the customer's home. In any case, the packaging is designed for a short storage period, especially of the ground product.

The packaging for whole beans, which have little or no barrier properties against gases or aromas, have the disadvantage that the coffee beans on the one hand lose volatile flavors very quickly, on the other hand oxygen can reach the coffee beans almost unhindered, so that they oxidize and thus bad taste-intensive fatty acid derivatives arise. As already stated, such packaging is only for very short storage positions, for example of a week usable. The coffee scrap is high here.

Valve packaging

Composite foils are used both for ground coffee and for whole beans with higher durability requirements, but less on the basis of aluminum foils, but mostly on the basis of aluminum-coated polyester or polypropylene foils. An additional valve allows released C0 _{2 to} escape. The valve packaging has the disadvantage that, on the one hand, the packaging is very complex. The valves make the packaging considerably more expensive. In addition, the valves have to be arranged in the packaging, which also makes the manufacturing process more expensive. In addition, the valves must be disposed of after using the packing.

On the other hand, the valve packaging has the disadvantage that volatile aroma substances can also escape through the valves.

Vacuum packaging

In vacuum coffee, composite foils based on aluminum foil are used, which are practically completely sealed. These allow a long minimum shelf life (in Germany, trade currently requires one and a half years). The vacuum packaging has the disadvantage that the packaging process takes a relatively long time. In the case of ground coffee, in which the gas is released relatively quickly and the amount of gas has already been reduced by the grinding, the problem arises that a gas-tight packing is the result of this Gas release inflates, thereby avoiding that the coffee is temporarily stored before being packaged for degassing under the exclusion of oxygen. Another possibility is to release the excess gas from the packaging by providing the packaging with a valve filter that allows gas to escape from the packaging if the internal pressure exceeds a certain level, but at the same time prevents ambient air containing oxygen from entering (Rothfos, loc. Cit , Page 242). As already mentioned, the intermediate storage takes time and a certain space for the intermediate storage during the actual packaging process. In addition, aromas can escape from the coffee. If you do not pay attention to a low-oxygen environment, the coffee also oxidizes, which, as already mentioned, is also disadvantageous.

The technical problem on which the invention is based is to provide a packaging for roasted and / or roasted coffee in ground or unground form which is simple and inexpensive to produce and which, moreover, maintains the aroma of the coffee over long storage times, in which the aromas are largely remain in the coffee and which has a relatively low overpressure during the storage period. In addition, a method for packaging coffee is to be specified. This technical problem is solved by the features of claim 1 and by the features of claim 32.

Characterized in that the packaging according to the invention for the roasted and / or roasted coffee has a packaging sleeve which at least partially consists of at least one ner stretchable plastic film, and which is also designed such that an internal pressure in the packaging caused by gases outgassing the coffee is less than the bursting pressure of the packaging and / or the closure of the packaging, it is possible to make the coffee immediately after Fill the roasting process into the packaging without intermediate storage times or with short storage times for outgassing and close the packaging tightly.

The packaging according to the invention can be used for roasted and / or roasted coffee in ground or unground form. Coffee is often roasted for preservation, transported and finally roasted somewhere. Roasted coffee also releases C0 ₂ , so that the packaging according to the invention is also advantageous for roasted coffee.

The following process steps are carried out to pack the coffee:

1. The coffee is introduced into the packaging according to the invention.

2. The packaging is tightly closed.

3. The coffee degasses in packaging C0 ₂ .

4. Outgassing the C0 ₂ increases the internal pressure in the packaging.

5. The packaging material expands from a predetermined internal pressure. The properties of the plastic film define the predetermined internal pressure at which the packaging material begins to stretch. The internal pressure remains so low during outgassing that the bursting pressure of the packaging is not reached, also not the bursting pressure of the seams and / or the bursting pressure. pressure of the closure (s). There is a significant increase in volume of the packaging; the internal pressure in the packaging does not increase or only increases very slightly.

6. The C0 ₂ - partial pressure in the gas space of the packaging rises so much that the outgassing speed of the coffee is reduced so much that a dynamic equilibrium is established between the further outgassing amount and the diffusion of C0 ₂ through the packaging material to the outside.

7. As a result, there is no further stretching of the packaging material.

Regarding item 5, it must be stated that the packaging according to the invention expands, for example, from an internal pressure of approximately 1.15 bar, so that there is no longer an increase in pressure in the packaging from this internal pressure. This means that the absolute internal pressure remains approximately constant. So you no longer have an increase in pressure, but an increase in volume. It is state of the art to predefine the stretching behavior of a plastic film, for example via the use of the raw material materials and / or the production processes and / or the layer thickness.

According to point 6, the C0 ₂ percentage in the packaging increases. The outgassing in the form of C0 _{2 from} the coffee depends on the initially existing C0 ₂ partial pressure of the environment. With a low C0 ₂ partial pressure in the environment, a larger C0 ₂ portion fumes out than with a high C0 ₂ partial pressure in the surroundings. For example, if the CO ₂ has exceeded approximately 50% of the total gas volume in the packaging and the gas pressure in the packaging is approximately 1.15 bar, the outgassing of the coffee slows down significantly. It turns out, as already mentions a dynamic balance between the further outgassing amount and the diffusion of C0 ₂ through the packaging to the outside.

This point, at which the outgassing slows down considerably, lies in the case of the packaging according to the invention before the point which is normally customary and known in the prior art. This is based on the fact that the prior art relates to measurements in a natural external atmosphere (approx. 1 bar) and a natural atmospheric composition (C0 ₂ content approx. 0.03%). The special combination in the packaging according to the invention of increased gas pressure (approx. 1.15 bar) and significantly increased CO ₂ content in the gas space of the packaging (from approx. 50% CO ₂ ) enables the further slow down of the CO ₂ outgassing of the coffee. The percentage of C0 ₂ at which this effect begins depends on the type of coffee, the degree of roasting and the type of coffee (ground or beans).

The specified values differ depending on the type of coffee.

A major advantage of the invention is that a maximum internal pressure is created in the packaging according to the invention, which is completely harmless. Because the packaging according to the invention expands from a certain internal pressure, for example at an internal pressure of 1.15 bar, the packaging according to the invention is completely harmless.

Another advantage of the packaging according to the invention is that almost all flavorings are retained. The aromas hardly diffuse through the packaging and cannot escape through another opening. Another advantage of the invention is that almost no oxygen can diffuse into the package. For this reason, there is only limited oxidation of the coffee in the packaging according to the invention, since only a limited amount of oxygen is enclosed in the packaging during the packaging process. In order to largely prevent even this slight oxidation, it is possible according to the invention to introduce C0 ₂ into the packaging during the packaging process.

This procedure achieves the C0 ₂ partial pressure earlier, at which the coffee stops its outgassing or at least slows it down considerably. If desired, this can be used as a further advantage.

The packaging according to the invention also has the advantages that the coffee has a very long shelf life, the actual packaging process is simple and the coffee remains fresh and aromatic for a long time. In addition, the tips of the coffee are broken, which means that a mild taste is achieved because the bitter substances are no longer or to a lesser extent present.

If the properties of the stretchable material described so far are supplemented such that it is also elastic, there is a further advantage due to the restoring forces that are now present. The packaging expands due to the C0 ₂ outgassing of the coffee. During this stage, a certain proportion of C0 ₂ diffuses through the plastic film of the packaging according to the invention. In this first stage, more CO _{2 is} emitted than diffuses through the plastic film. In a second stage, the outgassing and the Diffusion in the balance. Outgassing and diffusion are in a dynamic equilibrium. This condition lasts for six to nine months, depending on the type of coffee. In a third stage, the outgassing decreases, so that now more CO ₂ diffuses through the plastic film of the packaging according to the invention than outgasses from the coffee. If the plastic film of the packaging sleeve according to the invention is elastic, the restoring forces now act in such a way that the packaging according to the invention contracts. This ensures that even with decreasing outgassing, the packaging according to the invention makes a good visual and aesthetic impression and the slightly increased internal pressure (1.1 to 1.2 bar) is maintained.

The plastic film from which the packaging according to the invention is formed can be designed according to the invention in one or more layers.

The plastic film advantageously has a gas barrier layer in such a way that the plastic film is at least approximately gas-tight. In the optimal case, it is desirable that no oxygen diffuses from outside to inside, and that no CO ₂ diffuses from inside to outside.

As single-layer, stretchable plastic films, for example, films made of polyethylene can be used which have an expansion behavior such that an internal pressure resulting from outgassing is less than the bursting pressure of the packaging or the closure of the packaging.

The plastic film advantageously has an oxygen permeability of cm*

1 to 50 m ² ■ day ■ bar

on. The oxygen permeability is preferably included

15 to 30 m ² day bar

This value applies to the conditions at 23 ° C and a relative humidity of 75% with a test method that works with pure oxygen.

The carbon dioxide permeability of the film advantageously has a size of

2 to 300 m ² - day • bar

preferably from

cm'

30 to 100 m ² - day - bar

on, at 23 ° C and a relative humidity of 0% with a test method that works with pure C0 ₂ .

However, it is also possible to use plastic films which have a different oxygen permeability and / or a different carbon dioxide permeability.

The gas permeability of the plastic film of the packaging according to the invention is determined by the composition of the Plastic material, defined by the manufacturing method and the layer thickness.

Single-layer elastic plastic films advantageously consist of polyethylene modified with metallocenes. The metallocenes make the film elastic. But it is also possible to use other food-safe elastomers.

Elastic polyethylene materials for producing the packaging according to the invention are known under the name "EXACT" (trade name) from Exxon Chemicals (company name) or "Affinity" (trade name) from Dow Chemicals (company name).

The multilayer plastic films can be produced in several layers and then laminated or laminated or glued.

It is also possible to produce the multilayer films by coextrusion, for example as blown goods (blown film) or as a flat web (cast film).

In the case of multilayer films, at least one layer is designed to be stretchable or elastic. A plastic film is provided as the elastomer, which consists either of polyurethane or modified, preferably modified with metallocenes, polyethylene.

The gas barrier layer, or to a lesser extent gas-permeable layer, is advantageously arranged in the middle between further layers of the multilayer plastic film. The gas barrier layer can consist of polyamides and / or ethylene vinyl alcohol (EVOH) and / or polyvinyl dichloride (PVDC) and / or polyvinyl chloride (PVC). If a multilayer film is used, the film preferably has five layers with the following layer structure:

- First layer (elastic layer): modified PE, preferably modified with metallocenes - layer thickness, for example 65 µm, available from Dow Chemicals

(Company name);

- second layer: adhesive - layer thickness, for example 3 µm to 5 µm;

- third layer: ethylene vinyl alcohol (EVOH) (gas barrier layer) - layer thickness, for example 5 μm to 10 μm;

fourth layer: adhesive - layer thickness, for example 3 µm to 5 µm;

- fifth layer: (elastic layer): modified PE, preferably modified with metallocenes - layer thickness, for example 65 μm, available from Dow Chemicals

(Company name).

According to the invention, the stretchability of the plastic film is at least 10%. The stretchability is advantageously between 80 and 100%. A higher elasticity is quite possible and also useful depending on the application.

According to the invention, the extensibility at which the film is in its elastic range is at least 50%.

The packaging according to the invention is advantageously designed as a bag, for example a tubular bag. The plastic film as a flat web is advantageously processed on a tubular bag machine, for example on a vertical tubular bag machine. The tubular bag machine forms the bags from the plastic film and fills and seals them. The seams of the Bags can be welded thermally or at high frequency. Likewise, the bag can be thermally or high-frequency welded at the bottom edge and at the filling opening. It is also possible to close the bag with a clip. It is also possible to set the packaging and to seal the film.

The packaging sleeve is advantageously printed. It can be colored and / or transparent. It is also possible to include an information carrier in the packaging with information about the type of coffee, the manufacturer, the filling quantity and the like.

According to the method according to the invention, the coffee is arranged in the packaging according to the invention after roasting without intermediate storage for outgassing. This has the advantage that no storage time and no storage spaces are required.

The coffee can therefore be filled directly or almost immediately into the packaging envelope according to the invention, and the packaging can then be tightly closed so that it can be transported on to the distributor without delay.

During the packaging process, a head space can remain in the packaging. However, it is also possible to pack the coffee without or only with a very small head space. The headspace can be up to one sixth of the fill height, for example.

According to the invention, the packaging according to the invention with the filled coffee in an outer packaging can be ordered. The outer packaging can hold one or more bags.

In order to convey information about the type of coffee, the manufacturer, the filling quantity and the like, it is possible to arrange an information carrier in the bag before closing the bag, wherein the information carrier can be designed, for example, as a badge, label or the like.

According to the method according to the invention and with the packaging according to the invention, it is also possible to choose small packaging units. A packaging unit can contain, for example, the amount of ground coffee that is necessary to brew a pot of coffee.

The feature that the packaging sleeve is stretchable in an area, that the internal pressure resulting from the outgassing is less than the bursting pressure of the packaging, is to be understood in such a way that neither the plastic film of the packaging tears nor that seams, in particular weld seams of the packaging, are destroyed . In addition, the internal pressure must be less than a burst pressure of the closure of the packaging.

In other words, the stretching behavior of the plastic film is designed in such a way that the volume of the packaging increases due to the internal pressure and a further substantial increase in the internal pressure is avoided as a result.

According to the invention, the packaging can be designed in such a way that part of the packaging consists of a stretchable and / or or elastic material, and that another part of the packaging consists of a material that is not stretchable or non-elastic, for example a plastic plate or metal plate. It is also possible to combine a stretchy material with an elastic material.

The combination of stretchable, elastic, non-stretchable and non-elastic materials has the advantage that, for example, a base of the packaging (bottom) is made of a non-stretchable and non-elastic material, for example in the manner of a tray packaging. This area of the packaging does not expand when the coffee is outgassed, so that the stability of the packaging remains guaranteed. It is also possible to make a film non-stretchable and a film elastic in a bag made from two films. All advantages according to the invention are realized with this packaging. However, taking advantage of all the advantages, it is possible to save costs, since non-stretchable plastic films may be less expensive than stretchable or elastic films.

The packaging according to the invention is advantageously designed in such a way that the volume increase of the entire packaging due to the expansion of the plastic film after closing is at least 10%. This ensures that the volume of the packaging increases as a result of the strong outgassing of the coffee and that the internal pressure in the packaging does not increase significantly as soon as it expands.

The internal pressure in the packaging is advantageously 1.10 to 1.15 bar and hardly exceeds this value. In Under no circumstances is there a pressure of more than 1.3 bar in the packaging according to the invention, regardless of the storage time.

The volume available for outgassing the coffee in the packaging preferably corresponds to at least 20% of the volume of the coffee packaged in the packaging. It is possible that this volume is present from the outset and / or is generated by the expansion of the plastic.

According to the invention, the percentage increase in volume is greater than the percentage increase in pressure. This means that in the packaging, for example, there is an increase in pressure of 10% from 1 bar to 1.1 bar and an increase in volume of 20 or 30%.

As already stated several times, it is necessary that the internal pressure in the packaging is at least temporarily higher than the pressure of the external atmosphere. This is the only way to stop the outgassing of the coffee.

An example is given below.

A multilayer film is used, which has the following layer structure:

- First layer (elastic layer): PE modified with metallocenes, layer thickness 65 µm, available from Dow Chemicals (company name);

- second layer: adhesive - layer thickness 5 µm;

- third layer: ethylene vinyl alcohol (EVOH) - layer thickness 5 µm; - fourth layer: adhesive - layer thickness 5 µm;

- fifth layer: (elastic layer): PE layer thickness modified with metallocenes, 65 μm, available from Dow Chemicals (company name).

This film is elastically stretchable, at least by 80%. This means that after 80% expansion after the expansion forces cease to exist, this material shows a backward behavior with a predominantly linear force-displacement curve over significantly more than 50% of the recovery range, starting from the point of recovery. The above film is elastic up to 10% of the remaining stretch.

The stretching of the material is triggered from a force on the material of approximately 1 Newton / cm ² .

This means that the material begins to expand from an effective air pressure of approximately 0.1 bar (absolute pressure 1.1 bar). During the further expansion, the overpressure required for this usually rises to 0.15 bar (absolute pressure 1.15 bar) and then remains approximately constant.

One liter of coffee beans is placed in this packaging made of the specified material, which has a volume of one liter. Small gas spaces of around 0.1 liters remain between the beans.

Outgassing the coffee initially increases the amount of gas in the packaging until it completely fills the packaging. By further degassing the coffee, the pressure rises to approximately 1.1 bar. From this gas pressure in the packaging, the further outgassing of the coffee acts in such a way that the plastic material expands and the packaging thus increases its overall volume. Depending on the type of coffee, but with an increase in volume of around 40% and an ongoing pressure of 1.10 to 1.15 bar in total, the coffee slows down its outgassing significantly. The C0 ₂ portion of the total amount of gas is approximately 80%.

A dynamic equilibrium is established between the amount of C0 ₂ that is now outgassing and the C0 ₂ that diffuses through the packaging.

Further details of the invention can be found in the subclaims.

An exemplary embodiment of the invention is shown in the drawing, namely:

1 shows a packaging according to the invention

Front view of coffee beans after packaging, partially broken open;

FIG. 2 shows the packaging according to FIG. 1 with coffee beans after a certain storage time in front view, partially broken open;

3 shows the packaging according to FIG. 1 after a certain storage time in a side view, partially broken open;

Fig. 4 shows a modified embodiment with coffee powder in front view, partially broken away; Fig. 5 portion packs in front view, partially broken away;

6a,

6b,

6c an elastic packaging in view, partially broken open, at different time intervals;

7 shows a packaging with a stretchable and a non-stretchable plastic film in cross section;

Fig. 8 is a multi-layer plastic film in section.

Fig. 1 shows a packaging (1) according to the invention with a plastic film (11) which is filled with coffee beans (2). The packaging (1) is filled with coffee beans (2) in such a way that a head space (22) remains. The coffee beans (2) were filled into the packaging (1) immediately after roasting, and the packaging (1) was thermally sealed immediately after the coffee beans (2) had been filled. It has welds (3).

2 and 3 show the packaging (1) after a longer storage period, for example of two months. The C0 ₂ outgassed from the coffee beans (2) is in the gas space of the packaging (1) and has stretched it. The volume of the packaging (1) has increased as a result of the stretching. For this reason, the head space (22) is enlarged. The layer thickness of the plastic film (11) of the packaging (1) is reduced. 4 is ground coffee (12) in a package

(13) arranged. The packaging (13) is with a clip

(14) tightly closed. The packaging (13) is completely filled with coffee powder. Step C0 ₂ out of the coffee powder

(12) During the storage period, the packaging expands

(13).

5, a package (15) is shown which has a plurality of portion packs (15a, 15b, 15c, 15d). Coffee beans (16) are arranged in the portion packs (15a, 15b, 15c, 15d). Coffee powder can also be arranged in the portion packs (15a, 15b, 15c, 15d).

The portion packs (15a, 15b, 15c, 15d) each contain an amount of coffee beans (16) or coffee powder (not shown) which is required, for example, for brewing a pot of coffee, for example for brewing ten cups of coffee. Perforation lines (17) for separating the packs (15a, 15b, 15c, 15d) are provided between the portion packs (15a, 15b, 15c, 15d).

Fig. 6a shows a package (18) which is completely filled with coffee beans (19). The packaging (18) has a plastic film (20), the plastic film (20) according to FIG. 6a not being stretched.

6b, the packaging (18) has been stored for a certain time. The packaging (18), that is to say the plastic film (20), is now in a stretched state. The outgassing of C0 ₂ from the coffee beans (19) initially increased the amount of gas in the packaging (18) and thereby completely filled the packaging (18). By further degassing the coffee beans (19) increases the gas pressure in the package (18) to a higher value than the pressure of the external atmosphere. As a result, force in the form of pressure is exerted on the inner surface of the packaging (18). When a force is predefined by the stretching behavior of the plastic film (20), the plastic film (20) expands and thus increases the volume of the packaging (18). This prevents a further increase in pressure.

The coffee beans (19) are now arranged in the packaging (18) in such a way that a head space (23) is present. The C0 ₂ emerging from the coffee beans (19) diffuses in part through the plastic film (20). The proportion of outgassing CO ₂ from the coffee beans (19) is greater than the proportion of CO ₂ diffusing through the plastic film (20) into the exterior, so that the plastic film (20) expands at this stage. The plastic film (20) prevents leakage or reduces the escape of aromatic substances. These remain in the interior (21) of the packaging (18). In addition, little or no oxygen escapes from the outside into the interior (21) of the packaging (18), so that the coffee beans (19) can only be oxidized by the proportion of oxygen originally contained in the packaging.

According to Fig. 6c, the amount of degassing CO _{2 of} the coffee beans (19) has dropped sharply. At this stage, more CO ₂ diffuses out of the interior (21) through the plastic film (20) than outgasses from the coffee beans (19). The restoring forces of the elastic packaging (20) cause the packaging (18) to contract and thus compensate for the loss of gas volume. The packaging (18) remains a packaging with a smooth and curved surface due to the elastic restoring forces. The Packaging (18) also looks optically advantageous at this stage.

Fig. 7 shows a package (24) which consists of a non-stretch plastic film (25) and a stretch plastic film (26). Coffee beans (27) are arranged in the packaging (24). The packaging shown in Fig. 7 has expanded due to the C0 ₂ outgassing from the coffee beans (27). Since only the plastic film (26) is designed as an expandable plastic film, only the plastic film (26) has also expanded. The plastic film (25) is still in an unstretched state.

This embodiment can be useful for cost reasons, for example. However, it is also possible to choose such a packaging in order to be able to form stable coffee packaging.

8, a multi-layer plastic film (5) is shown. The plastic film (5) has, as the first layer (6), a polyethylene layer modified with metallocenes. The second layer consists of an adhesive (7). A middle layer (8) is formed as a gas barrier layer, specifically from ethylene vinyl alcohol. Another layer (9) in turn consists of an adhesive. The last layer (10) in turn consists of polyethylene modified with metallocenes. The layers (6 and 10) are designed as elastic layers and have the greatest layer thickness. The layers (7 and 9) are adhesive layers for connecting the elastic layers (6 and 10) to the gas barrier layer (8). Reference numbers

1 package

2 coffee beans

3 welds

5 plastic film

6 polyethylene layer

7 glue

8 gas barrier layer

9 glue

10 PE layer

11 plastic film

12 ground coffee

13 packaging

14 clips

15 packaging

15a to 15d portion packs

16 coffee beans

17 perforation lines

18 packaging

19 coffee beans

20 plastic film

21 interior

22 headroom

23 headroom

24 packaging

25 plastic film

26 plastic film

27 coffee beans

Claims

claims

1. Packaging for roasted and / or roasted coffee, that is, that the packaging (1, 13, 15, 18, 24) consists at least partially of at least one stretchable plastic film (5, 11, 20); b) that a stretching behavior of the plastic film (5, 11, 20) is designed in such a way that stretching can be achieved by an internal pressure in the tightly sealed packaging (1, 13, 15, 18, 24); c) that the stretching of the plastic film (5, 11, 20) takes place at a gas pressure in the packaging, such that the gas pressure is less than a burst pressure of the packaging (1, 13, 15, 18, 24) and / or a closure of the Packaging is; and d) that the stretching behavior of the plastic film (5, 11, 20) is designed such that in the packaging (1, 13, 15, 18, 24), at least temporarily during the storage period of the coffee (2, 12, 16, 19 ), a higher pressure than an external atmosphere pressure is present.

2. Packaging according to claim 1, characterized in that the packaging (1, 13, 15, 18, 24) consists at least partially of at least one elastic plastic film (6, 10).

3. Packaging according to claim 1, characterized in that a percentage increase in volume of the packaging (1, 13, 15, 18, 24) is greater than a percentage increase in gas pressure in the packaging (1, 13, 15, 18, 24).

4. Packaging according to claim 1 or 2, characterized in that the at least one plastic film is formed in one or more layers.

5. Packaging according to claim 1 or 2, characterized in that the at least one plastic film has a gas barrier layer (8).

6. Packaging according to claim 5, characterized in that the gas barrier layer (8) has a predefined permeability to certain gases.

7. Packaging according to claim 4, characterized in that at least one film layer (8) is designed as a gas barrier layer.

8. Packaging according to claim 5, 6 or 7, characterized in that the gas barrier layer (8) consists of polyamides and / or ethylene vinyl alcohol (EVOH) and / or polyvinyl dichloride (PVDC) and / or polyvinyl chloride (PVC).

9. Packaging according to claim 7, characterized in that the gas barrier layer (8) is arranged between at least two further film layers (6, 10) of the multilayer plastic film.

10. Packaging according to claim 4, characterized in that the single-layer plastic film consists of modified polyethylene (PE).

11. Packaging according to claim 10, characterized in that the single-layer plastic film consists of modified with metallocenes polyethylene (PE).

12. Packaging according to claim 1, characterized in that the plastic film has an oxygen permeability of

exhibits at 23 ° C and a relative humidity of 75%.

13. Packaging according to claim 1, characterized in that the plastic film has a carbon dioxide permeability of

~, "Cm ³ 2 to 300 m ² • day • bar

exhibits at 23 ° C and 0% relative humidity.

14. Packaging according to claim 4, characterized in that the multilayer plastic film consists of several loosely lying film layers.

15. Packaging according to claim 4, characterized in that the multi-layer plastic film consists of a plurality of film layers (6, 8, 10) lying firmly on one another.

16. Packaging according to claim 15, characterized in that the plurality of film layers (6, 8, 10) of the plastic film are laminated together.

17. Packaging according to claim 4, characterized in that the multilayer plastic film is designed as a plastic film produced by co-extrusion.

18. Packaging according to claim 4, characterized in that the multilayer plastic film is designed as a blown film or cast film (flat web) made of plastic film.

19. Packaging according to claim 4, characterized in that at least one film layer (6, 10) is elastic.

20. Packaging according to claim 19, characterized in that the at least one elastic film layer (6, 10) consists of polyurethane (PU) or modified polyethylene (PE).

21. Packaging according to claim 19, characterized in that at least one elastic film layer (6, 10) consists of polyethylene (PE) modified with metallocenes.

22. Packaging according to claim 4, characterized in that the plastic film consists of the following layers:

- First layer (6): polyethylene, modified with

Metallocenes;

- second layer (7) of adhesive;

- third layer (8) ethylene vinyl alcohol (EVOH);

- fourth layer (9) of adhesive; fifth layer (10): polyethylene, modified with

Metallocenes.

23. Packaging according to claim 22, characterized in that the film layers (6, 7, 8, 9, 10) have the following layer thicknesses:

- first layer (6): 20 µm to 120 µm;

- second layer (7): 3 µm to 7 µm; - third layer (8): 5 µm to 30 µm;

- fourth layer (9): 3 µm to 7 µm;

- fifth layer (10): 20 μm to 120 μm.

24. Packaging according to claim 4, characterized in that a polyethylene / polyamide film (PE / PA film) is provided, which has the following structure:

- First layer: PA 6, layer thickness 20 μm to 40 μm;

- Second layer: adhesion promoter, layer thickness 5 μm to

10 µm;

- third layer: modified polyethylene, layer thickness

40 μm to 100 μm.

25. Packaging according to one of the preceding claims, characterized in that "EXACT" (trade name) from Exxon Chemicals (company name) or "Affinity" (trade name) from Dow Chemicals (company name) is provided as the elastic PE material.

26. Packaging according to claim 1, characterized in that the packaging (1, 13, 15, 18, 24) has an extensibility of at least 10%.

27. Packaging according to claim 1, characterized in that the packaging (1, 13, 15, 18, 24) has an extensibility of 80% to 100%.

28. Packaging according to claim 2, characterized in that the packaging (1, 13, 15, 18, 24) has an extensibility in the elastic range of at least 50%.

29. Packaging according to one of the preceding claims, characterized in that the packaging (1, 13, 15, 18, 24) is designed as a bag.

30. Packaging according to one of the preceding claims, characterized in that the packaging is transparent and / or printed and / or colored.

31. Packaging according to one of the preceding claims, characterized in that an information carrier is arranged in and / or on the packaging (1, 13, 15, 18, 24).

32. A method for packaging roasted and / or roasted coffee, in which the coffee is arranged in the packaging after roasting or roasting, characterized in that

that a packaging (1, 13, 15, 18, 24) is used which consists at least partially of at least one stretchable plastic film, the packaging (1, 13, 15, 18, 24) being stretchable in one area, such that that an internal pressure in the packaging (1, 13, 15, 18, 24) caused by gases outgassing the coffee (2, 12, 16, 19) by gases is less than a burst pressure of the packaging and / or a closure of the packaging,

- that the packaging (1, 13, 15, 18, 24) is tightly closed after the coffee has been filled,

the internal pressure in the packaging (1, 13, 15, 18, 24) then increases due to the outgassing of the coffee (2, 12, 16, 19),

- that the packaging expands from an internal pressure which is less than the bursting pressure of the packaging and / or the bursting pressure of the closure, - That the resulting internal pressure in the packaging (1, 13, 15, 18, 24) is at least temporarily higher than the pressure of the external atmosphere.

33. The method according to claim 32, characterized in that the coffee is arranged after roasting and / or roasting substantially without intermediate storage for outgassing in the package.

34. The method according to claim 32, characterized in that a packaging consisting of at least one elastic plastic film (5, 11, 20) is used as the packaging (1, 13, 15, 18, 24).

35. The method according to claim 32, characterized in that the packaging (1, 13, 15, 18, 24) is sealed by welding.

36. The method according to claim 32, characterized in that the packaging (1, 13, 15, 18, 24) is sealed with at least one clip (14) or by binding.

37. The method according to claim 32, characterized in that carbon dioxide during the packaging process

(C0 ₂ ) in the packaging (1, 13, 15, 18, 24) is introduced.

38. The method according to claim 32, characterized in that the packaging of the coffee (2, 12, 16, 19) is carried out with a tubular bag machine.

39. The method according to claim 32, characterized in that during the packaging process there is little or no head space in the packaging over the coffee.

40. The method according to claim 32, characterized in that the packaging (1, 13, 15, 18, 24) is arranged in an outer packaging after closing.

41. The method according to claim 32, characterized in that an information carrier is arranged in the packaging before closing the packaging.

42. The method according to claim 32, characterized in that the packaging is printed or an information carrier is applied.

43. The method according to claim 32, characterized in that portion packs (15a to 15d) are packaged.