GB2390355A

GB2390355A - Coffee packaging process with nitrogen

Info

Publication number: GB2390355A
Application number: GB0215210A
Authority: GB
Inventors: Patrick Bewley
Original assignee: VALMAS Manufacturing Ltd
Current assignee: VALMAS Manufacturing Ltd
Priority date: 2002-07-01
Filing date: 2002-07-01
Publication date: 2004-01-07
Anticipated expiration: 2022-07-01
Also published as: GB0215210D0; GB2390355B

Abstract

A coffee production process uses a form-fill-seal operation to pack ground coffee with nitrogen. As the coffee is fed into the web of material 15a by the tube 5, nitrogen is also fed in via a second tube 6. The web of material 15a incorporates one-way valves, to allow gasses evolved from the packed coffee to vent. Prior to packing, the ground coffee is retained in holding bins for at least two hours to release excess carbon dioxide. The filled bags formed by the process are rejected if oxygen comprises more than 5.0% of the gas within the bag.

Description

À - 1 "A Coffee Conditioning and Packing Svstem" Introduction

5 The present invention relates to a coffee production process and in particular to that part of the process after the roasting and grinding of the coffee beans.

When coffee beans are ground, they give off a considerable amount of CO,. As the coffee beans lose CO2 and particularly as ground coffee beans lose CO2, their 10 organoleptic properties reduce. It is known, for example, to vacuum pack ground coffee, however, before the ground coffee can be packed, a considerable amount of CO2 has to be released and this reduces the subsequent taste of the coffee.

It is further known to freeze dry coffee, again with reduction of organoleptic properties.

15 The ideal situation is to store the coffee relatively quickly after it is ground and to then allow any CO2 that subsequently generates in the pack to be vented off or in some way removed because if the CO2 is not removed, the pack would eventually burst allowing the ingress of oxygen. Further, it is desirable that the minimum amount of oxygen remain in the bag or pack, after packing, because when the oxygen in a pack 20 is above approximately 8% of the total ambient gas within the pack, the coffee deteriorates relatively rapidly and would generally deteriorate over a short period of months. It is desirable to have a shelf life for ground coffee of at least twelve months before it starts to seriously deteriorate.

25 It is known to evacuate the air from bags and fill with a pressurised inat gas such as carbon dioxide or nitrogen, such as described in GB Patent Specification No.

1070320. It is also known to provide a bag with a oneway valve in its side wall to allow the venting of CO2 during storage. This is described in our Irish Patent Specification No. IE 970556. Unfortunately, with such valves, there is still a

30 considerable amount of oxygen contained in the bag and additionally, the buildup in pressure in the bag requires a very robust bag and a valve capable of a high throughput. The present invention is directed towards overcoming these problems by providing a

-2 better way of grinding and packing coffee after it has been roasted.

Statements of Invention

5 According to the invention, there is provided a coffee production process compising: roasting coffee beans; grinding the coffee beans; delivering ground coffee to a holding bin; retaining the coffee in the holding bin for a preset time of at least two hours to condition the coffee and to vent off carbon dioxide; leading a sheet of gas impermeable heat sealable material incorporating a plurality of longitudinally spacedapart venting valves around a pair of parallel substantially vertical pipes, namely, a coffee charging pipe fed from the holding bin and a gas delivery pipe fed from a nitrogen storage 20 tank, the gas delivery pipe having an outlet below a discharge outlet for the coffee charging pipe; overlapping the exposed side edges of the material to enclose the pipes as the material is drawn down over the pipes; heat sealing the material to form an enclosed tube around the pipes; drawing the tube down below the pipes; 30 transversely sealing the tube to form a bag bottom and the closure of a previously formed bag while separating the two; delivering a predetermined discrete amount of coffee down the enclosed coffee charging pipe;

-3 simultaneously delivering nitrogen, under pressure, through the gas delivery pipe; 5 continuing to draw the bag downwards as it is filled; transversely sealing the bag to Arm the bag closure; cutting the material to separate the bag from the next bag being formed; checking the oxygen concentration in the bag and rejecting the bag if the oxygen comprises more than 5.0% of the gas within the bag; and storing the bag at ambient pressure and temperature while allowing 15 excess carbon dioxide produced by the coffee to be vented off.

Originally, tests were carried out to ascertain the effectiveness of packing the coffee immediately after grinding. However, the problems stated above of obtaining a suitably strong bag and effective valve were encountered. Additionally, in spite of 20 flushing the bag with nitrogen and introducing pressurised nitrogen, there were unacceptable levels of oxygen. Further, the fact that the nitrogen then combined with the CO2 made it even more difficult to provide a suitably strong and effective bag.

Then surprisingly, retaining the coffee in the holding bin, initially tried to solve the 25 problems of material strength and valve capacity also considerably reduced the oxygen levels in the packed coffee and further solved the other problems of materials and valve capacity.

In one embodiment of the invention, the process comprises holding the coffee in the 30 holding bin for less than eight hours and ideally for approximately four hours.

Preferably, the nitrogen is delivered into the bag at a pressure of between 0.4 and 0.6 bar.

-4 ln one method of carrying out the invention, the concentration of oxygen in the bags is measured after sealing and if the oxygen concentration of the gas within the bag is greater than 3.0%, the bag is rejected.

5 Ideally, the bags are further held for 24 hours loosely arranged to allow for further vending of carbon dioxide prior to subsequent packing in boxes for distribution.

One process according to the invention comprises 10 delivering a predetermined volume of coffee into an open mouthed container having a discharge outlet, the container fomming one of a plurality of containers mounted around the periphery of a turntable mounted above a discharge hopper feeding the coffee charging pipe; 15 moving the turntable in discrete increments to move the container below a discharge outlet of the holding bin to a discharge position above the discharge hopper; implying one or more containers into the discharge hopper to form the 20 desired quantity of coffee to be packed in one bag; and then moving the turntable until the container is below the discharge outlet of the holding bin.

25 Detailed Description of the Invention

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 side view of a packing for the ground coffee beans, after roasting, Fig. 1(a) is an enlargement of the circled portion of Fig. 1,

- 5 Fig. 2 is a perspective view of portion of the apparatus illustrated in Fig. 1, Fig. 3 is another perspective view of portion of the apparatus of Fig. 1, substantially similar to that of Fig. 2, and Fig. 4 is a perspective view of another construction of apparatus according to the invention.

Referring to the drawings, and initially to Figs. 1 to 3 thereof, there is provided a coffee 10 production process. The first two steps of the cofee production process are not illustrated in the drawings and do not require any further description as they have

been described in our copending UK Patent Application No. 0210012.1. The description of the roasting and grinding of the coffee beans, as described in this

specification, are included here by way of reference.

Referring to the drawings and initially to Fig. 1, there is illustrated packing machinery, identified generally by the reference numeral 1, comprising a discharge pipe 2 fed from a holding bin (not shown) into a batching hopper 3 having a batching discharge 4 (not illustrated in detail) feeding a coffee charging pipe 5 mounted parallel to which is 20 a gas delivery pipe 6 fed from a pressurized nitrogen storage tank 7. The coffee charging pipe 5 has a discharge outlet 8 and the gas delivery pipe 6 has an outlet 9 below the discharge outlet 8 for the coffee charging pipe 5. The coffee charging pipe 5 and the gas delivery pipe 6 are illustrated partly by interrupted lines.

25 The packing machinery 1 further comprises a reel support 10 mounting a reel 11 of material, identified by the reference numeral 15. The material 15 is a suitable thermosealing gas impermeable packing material that can be heat sealed. The material contains, longitudinally spaced-apart between its side edges, venting valves such as the valve manufactured under the trademark THE DANISCO INTEGRATED 30 VALVE SYSTEM. The integrated valve has three layers, an external layer which is in contact with the atmosphere, and an internal layer which has contact with the interior of the bag. Intermediate the external and internal layers, is a "channels and positioned within this channel. is the intemmediate unlaminated layer. Each of the layers has a number of perforations all of which are offset in relation to each other. The channel.

-6 contains silicone oil. The valve is made by leaving an approximately 10 to 15mm wide rechannels between the top film layer and the internal film layer. The "channel" is filled with silicone oil acting as a flexible bond between the top film layer and the internal film layer. When the pressure inside the pack rises compared to the atmosphere, the 5 overpressure is released through a perforation in the internal film layer into the channel" were it will separate the two film layers. The gas will follow the channel to the offset perforations in the top layer and disappear out to the atmosphere. When the internal overpressure is equalized, the top film layer will adhere to the internal film layer by means of the silicone oil, thus preventing atmospheric air from entering the 10 pack. The valve will open at an internal overpressure of approximately 20 mbar and ideally operate within a range of between 8 to 15 mbar depending on the type of laminate used. As the valve only opens at an internal pressure exceeding the atmospheric pressure, it works only as a one way valve.

15 The packing machinery 1 comprises a plurality of rollers 17 for leading the material 15 through a printing head 20, then to a guide chute 25 tFig. 2) which gradually raises the sheet of material down over and around the coffee charging pipe 5 and the gas delivery pipe 6. Mounted adjacent the coffee charging pipe 5 and the gas delivery pipe 6 is a heat sealer 30 movable back and forth in the diection of the arrows A by a 20 cantilevered actuator 31. Mounted below the outlet 9 of the gas delivery pipe 6 and the discharge outlet 8 of the coffee charging pipe 5 is a further heat sealing and cutting mechanism, indicated generally by the reference numeral 35. The heat sealing and cutting mechanism is a standard conventional heat sealer and heat cutting device. Below the combined heat sealing and cutting device 35 is mounted a 25 take-off conveyor 36.

A pair of driving conveyors, indicated generally by he reference numeral 40 and illustrated more clearly in Fig. 3, are provided. The driving conveyors 40 comprise belts 41 mounted between rollers 42, one of which is a driven roller. The driving 30 conveyors 40 are mounted on either side of the coffee chargng pipe 5 and the gas delivery pipe 6 to contact material and to pull the material 15 down beyond the end of the coffee discharge pipe 5 and the gas delivery pipe 6. It will be appreciated that, in operation, when coffee is delivered into the bags forrnedin the material, the weight will be sufficient to continue to drag the material down beyond the coffee charging pipe 5

and the gas delivery pipe 6.

In operation, material 15 is pulled off the reel 11 and when it passes the printing head 20, it is date printed or any other relevant indicia are printed thereon. The material 15 5 then progresses over further rollers 17 to the guide chute 25 where the edges of the material 15 are raised upwardly and guided around between the driving conveyors 40 where the material is pulled downwards around the coffee charging pipe 5 and the gas delivery pipe 6. When a certain amount of the material has been drawn downwards, the edges of the material which will have overlapped are then heat 10 sealed by the heat sealer 30. The heat sealer 30 is pushed inwards and outwards in the direction of the arrows A, against the side of the material as it is pulled downwards, thus heat sealing the material 15 into a tube which is identified in the drawings by the reference numeral 15(a). Futher progression of the tube downwards brings it to the heat sealing and cutting mechanism 35 where the material is heat 15 sealed. This transverse seal across the tube 15(a) eventually forms the bottom of a bag 15(b). At that stage, a predetermined discreet amount of coffee is delivered down the enclosed coffee charging pipe 5 into the bottom of the sealed tube 15(a). Also simultaneously, nitrogen at between 0.4 and 0.6 bar, is delivered down beyond into the tube 15(a). Generally, the nitrogen is delivered at approximately 0.5 bar. As the 20 tube 15(a) is dragged downwards, it passes the heat sealing and cutting mechanism 35 where it is now again heat sealed to form the top of the bag 15(b) or closure of the bag 15(b). Therefore, effectively what is happened here is that both the bottom of the next bag and the closure of the previous bag are formed each time by the heating sealing and cutting mechanism 35. They are also separated. Thus, bags 15(b) are 25 delivered to the conveyor 36. When the bags 15(b) aredelivered out the conveyor 36, they are usually stored loosely for some considerable time, either in cardboard boxes or the like, before they are eventually packed and sent for subsequent storage or delivery to customers.

30 Prior to packing the coffee beans, generally the ground coffee is delivered to a holding bin where it is retained in the holding bin for a preset Ume to condition the Coffee and to vend off carbon dioxide. Generally this is for at least two hours and less than eight hours and preferably of the order of four hours. Further, as the coffee is packed, a representative sample, statistically resolved, of bags 15(b), are removed and tested

-8 for oxygen content. Where the percentage of the oxygen is greater than 5% of the gas within the bag, linen the bag is rejected. Ideally, in many instances, the bag is rejected when the oxygen content is greater than 3%. Usually, after packing, the bags are held for about two hours loosely and up to twenty-four hours prior to packing in 5 any relatively tight container because a considerable amount of CO2 continues to be vented off.

In the embodiment described above, it will be appreciated that it is presumed that the correct amount of coffee is delivered into each bag.

Fig. 4 shows one metering device, indicated generally by the reference numeral 50, comprising a plurality of containers 51 each having an open mouth 62 and a discharge valve outlet (not illustrated) at 53, which is mounted around the periphery of a turntable 54 which is in turn mounted above a discharge hopper 55 feeding the 15 coffee charging pipe 5. In this embodiment, parts similar to those described with reference to the previous drawings, are identified by the same reference numerals.

Each container 51 has the same volumetric size, thusthe requisite batch size can be chosen as a multiple of numbers of containers. A suitable discharge pipe (not shown), from the holding bin, will fill each container 51 as it is indexed by the turntable beneath 20 it.

Further, there is provided a discharging station which is a mechanism which opens one or more of the containers 51 as they are indexed around the turntable 54 to provide, at the start position, the requisite numbers of container amounts of coffee into 25 the discharge hopper 55. This will provide the requisite amount of coffee.

It will be appreciated that with the present invention, by packing the ground coffee in what is effectively a nitrogen atmosphere, the amount of oxygen remaining in the packaging will be greatly reduced. Indeed, it has been found, in practice, that the 30 residual oxygen is of the order. of 1.7 to 2.7% of the total ambient gas within the container. This has been found to give extended shelf life. Further, the use of nitrogen greatly enhances the storage capabilities.

Further, because a venting valve is used, there is an additional advantage in the

-9 - marketng of the coffee which should not be overlooked, in that when the coffee is stored on shelves, particularly when it is newly arrived on shelves, there is a considerable amount of CO2 gas vented and the smell of fresh coffee is therefore vented off by the bags which encourages the consumer to purchase the coffee.

5 Generally, the valves are chosen so as to allow a certain amount of pressure to build up within the bag, but not too much, as it is essential not to cause the bag to burst.

The advantages of using the valve are that one can pack the coffee much earlier than heretofore and one can use a lighter packaging material than heretofore because there is relatively little possibility of the bag bursting.

It will also be noted that in the present invention, the gas delivery pipe is held well below the discharge outlet for the coffee, thus since the gas delivery pipe is operating continuously, as the bag is formed and prior b any coffee having been discharged therein, the gas is being delivered into the tube of material to force the ambient air out 15 of the tube. Thus, before any coffee is delivered into the tube, the atmosphere within the tube or open mouthed bag is nitrogen rich and oxygen deficient. It is effectively packaging within a nitrogen atmosphere, without all the problems inherent thereto.

It has been found important not to pack the bags too tightly initially but td allow them 20 vent for some time, at least 24 hours If they are packed too tightly, inevitably bags will burst as the pressure builds up within the bags and either the container in which they are in will not let them expand sufficiently prior to venting or the container may itself hold the vented gases causing further difficulties.

25 In the specification the terms Comprise, comprises, comprised and comprising" or any

variation thereof and the terms Uinclude, includes, included and including" or any variation thereof are considered to be totally interchangeable and they should all be afforded the widest possible interpretation and vice versa.

30 The invention is not limited to the embodiment hereinbefore described, but may be varied in both construction and detail within the scope of the appended claims.

Claims

- 1o- CLAIMS

1. A coffee production process comprising.

5 roasting coffee beans; grinding the coffee beans; delivering ground coffee to a holding bin; retaining the coffee in the holding bin for a preset time of at least two hours to condition the coffee and to vent off carbon dioxide; leading a sheet of gas impermeable heat sealable material incorporating a 15 plurality of longitudinally spaced-apart venting valves around a pair of parallel substantially vertical pipes, namely, a coffee charging pipe fat from the holding bin and a gas delivery pipe fed from a nitrogen storage tank, the gas delivery pipe having an outlet below a discharge outlet for the coffee charging pipe; overlapping the exposed side edges of the material to enclose the pipes as the material is drawn down over the pipes; heat sealing the material to form an enclosed tube around the pipes; drawing the tube down below the pipes; transversely sealing the tube to form a bag bottom and the closure of a previously fommed bag while separating the two; delivering a predetermined discrete amount of coffee down the enclosed coffee charging pipe; simultaneously delivering nitrogen, under pressure, through the gas

-11 delivery pipe; continuing to draw the bag downwards as it is filed; 5 transversely sealing the bag to fomm the bag closure; cutting the material to separate the bag from the next bag being formed; checking the oxygen concentration in the bag and rejecting the bag if the 10 oxygen comprises more than 5.0% of the gaswithin the bag; and storing the bag at ambient pressure and temperature while allowing excess carbon dioxide produced by the coffee to be vented off.

15

2. A process as claimed in claim 1, comprising holding the coffee in the holding bin for less than eight hours.

3. A process as claimed in claim 1, comprising holding the coffee in the holding bin for approximately four hours.

4. A process as claimed in any preceding claim, in which the nitrogen is delivered into the bag at a pressure of between 0.4 andO.6 bar.

5. A process as claimed in any preceding claim, in which the concentration of 25 oxygen in the bags is measured after sealing and if the oxygen concentration of the gas within the bag is greater than 3.0%, the bag is rejected.

6. A process as claimed in any preceding claim, in which the bags are further held - for 24 hours loosely arranged to allow for further venting of carbon dioxide prior 30 to subsequent padding in boxes for distribution.

7. A process as claimed in any preceding claim, comprising delivering the predetermined amounts of coffee by carrying out the steps of.

- 12 delivering a predetermined volume of coffee into an open mouthed container having a discharge outlet, the container romping one of a plurality of containers mounted around the periphery of a turntable mounted above a discharge hopper feeding the coffee charging pipe; moving the turntable in discrete increments to move the container below a discharge outlet of the holding bin to a discharge position above the discharge hopper; 10 implying one or more containers into the discharge hopper to form the desired quantity of coffee to be packed in one bag; and then moving the turntable until the container is below the discharge outlet of the holding bin.

8. A process substantially as described herein with reference to and as illustrated in the accompanying drawings.

9. Coffee produced in accordance with the process of any preceding claim.