AU3504699A - Process to prepare a packaged food product - Google Patents

Description

AUSTRALIA

PATENTS ACT 1990

ORIGINAL

COMPLETE SPECIFICATION 0*

S

STANDARD PATENT TITLE OF INVENTION *0

S

0000 9005 9009 PROCESS TO PREPARE A PACKAGED FOOD PRODUCT Name and Address of Applicant: UNILEVER PLC of Unilever House, Blackfriars, London EC4P 4BQ, England The following statement is a full description of this invention, including the best method of performing it known to me:- F3210 (C) -1- Process to prepare a packaged food product Technical Field of the Invention The invention relates to a process for the packaging of a food product in a flexible sachet, in particular, to confectionery products which are to be frozen in the sachet.

The invention also relates to a flexible sachet containing a food product produced by the process and to an apparatus for 10 carrying out this method.

oO.o Background of the Invention S" The packaging of food products in flexible sachets (or pouches as they may be called) is well-known. Examples Sinclude frozen foods such as ice-creams and ice-lollies and non-frozen foods such as nuts, crisps etc.

For example US 5,361,560 discloses the packaging of coffee and a flavoring in a flexible sachet and GB 1,102,485 discloses the packaging of meat products in a flexible casing. Also US 5,259,168 and EP 237113 disclose methods and apparatus for packaging articles in a plastic wrapper.

Flexible sachets have many advantages. For example they can be formed around the food product to package many types of food products. Also they can be prepared as the food product is ready to be packaged to allow the product to be produced and wrapped in almost a single operation. The sachets are also, typically, inexpensive and attractive to the consumer who may view the product through its' packaging (when made of transparent material) F3210(C) 2 The term sachet herein also encompasses packagings sometimes referred to in the art as 'pouches'. The term 'sachet' herein is intended to encompass food packaging which is flexible and may be formed around the food product.

Cardboard boxes are not however included in the term 'sachets' as now described and claimed. The sachet protects the food product during storage by providing a sealed covering which must be opened to provide access to the product inside.

A problem frequently encountered in the filling and/or storage of food products packaged in sachets is product expansion. This can occur when the product filled into the sachet is water-based and expands when frozen (such as water ices, etc.) or if the product expands upon non-frozen storage due to warming. The expansion may cause one or more undesirable effects including rupturing or straining of the sachet, leaking from the sachet seals and/or 'squashing' of contents of the sachet to produce a less visually e* 20 appealing product. Any of the aforementioned effects may make the packaged food product less attractive to the consumer, and more importantly, reduce its shelf- or storage-life.

Another problem often encountered is that the product can only be intermittently dosed into the sachet (especially if the food product is in a non-solid form when filled). This reduces the number of sachets that can be filled in a given time.

The present invention seeks to address the above technical problems.

F3210 (C) -3- Accordingly, the present invention provides a process for the packaging of a food product as given in Claim 1.

The present invention also provides a flexible sachet containing a food product packaged by the process of the present invention and an apparatus for the filling and production of a flexible sachet containing a food product.

The present invention provides several advantages. One is the avoidance of the 'over-expanding' of filled packages so that expansion problems during filling and/or storage are *0entirely or largely avoided. Another advantage associated with a particular embodiment is the ability to fill the sachets 'continuously', rather than intermittently which provides increased sachet-filling capacity whilst avoiding the over expansion problems.

Detailed Description The process of the present invention comprises several steps which will each be described in turn. However, if desired, two or more steps may be carried out simultaneously.

F3210 (C) -4- Step (i) At least one stream of an extrudable edible material is introduced into a flexible tube of the sachet material.

At least one stream of the extrudable edible material is in a slush form or a gel form when introduced into the tube.

It is preferred if the tube is moving when the filling occurs, especially preferred is that the tube is continuously moving when filling occurs.

o By gel is meant a high viscosity liquid recognised in the art as a gel. Examples include edible jellies. However the gel need not be 'set' to a solid but it must have a high viscosity.

Where two or more streams of extrudable edible material are introduced into the flexible tube it is preferred that these streams remain as distinct streams in the packaged food product, especially optically distinct co-continuous streams.

The 'slush' form of the edible material stream contains a mixture of ice and liquid water. Preferably the slush contains 10-60% by weight more preferably 15-55%, e.g. of ice based upon the weight of the respective stream at the temperature at which filling occurs. In some products it is preferred if the slush contains 25-45% ice when filling.

It is also possible to have at least one stream introduced in a slush form and at least one stream introduced in a gel form. This is advantageous for frozen products which are a F3210 (C) 5 mixture of a water ice/gel components. Here the temperature at which each stream is extruded would be appropriate to that stream.

Alternatively, or additionally, all streams may be in either a slush or a gel form when introduced.

The food product is preferably 'continuously' filled into the tube of sachet material, it is not extruded as a 'unit dose'. 'Continuously' as referred to herein means that the filling is extruded in a substantially constant, uninterrupted manner, and not in a series of 'unit doses'.

Obviously references to 'continuous' do not include when the packaging process is not in use.

S"In a particularly preferred embodiment the stream(s) are introduced continuously and the flexible tube moves continuously.

Typically the streams are introduced by an extrusion nozzle, or similar means, of a food product producing apparatus.

Any suitable means can be used to extrude the food product.

Although extrusion of the stream(s) can occur in many ways where two or more streams are introduced co-extrusion is preferred, especially where simultaneous and continuous.

However where a multitude of streams used, one or more stream(s) may be filled intermittently i.e. a particular colour stream can be switched on/off.

Preferably the flexible tube has at least one seal when filling occurs, e.g. a 'fin' seal along the longitudinal F3210 (C) -6length of the tube. However the sachet may be filled as a 'folded' tube and the seals produced afterwards The tube does not need to be completely filled in step (i) The flexible tube preferably moves continuously in step(i) and more preferably continuously throughout the packaging process. In other words when the tube is moving during filling it preferably does not move in a stepwise manner approximating to the length of each sachet) o In a particularly preferred embodiment the filling occurs continuously, the flexible tube moves continuously during filling, and the edible material stream or one or more component streams, preferably two or more, are in a slush form when filled into the moving flexible tube.

As stated above the flexible tube in step may be sealed along its' length before or during filling. The flexible 20 tube may, however, be in an 'unsealed' state during filling i.e. the tube is simply formed by folding the sachet material.

The flexible tube is preferably formed automatically from an open piece of the sachet material in a 'one-pass' sachet forming-filling-sealing arrangement. However a semi-sealed pre-formed sachet may also be used for filling e.g. having a pre-formed longitudinal or 'fin' seal.

It is preferred if the flexible tube in step is formed immediately prior to, or during step preferably by sealing, eg continuously, a moving length of the flexible sachet material along adjacent edges lying in the direction F3210 (C) -7of movement of the material. To make adjacent edges the two longitudinal or outer edges of the sachet material may be brought together by folding it into a tube shape. The longitudinal edges are then sealed, as the sachet material passes through the packaging apparatus. Generally the sachet material moves along a packaging machine going from an initial unsealed flat state, to an unsealed tube state, to a sealed tube state.

10 The filling occurs at a temperature suitable to the food product being packaged; this may be above or below 0°C 9e** according to the food product in question. For instance for products where one or more streams is/are in the 'slush' *state the temperature is typically below freezing e.g. -1C to preferably -1.50C to -4.5oC, such as -2°C to -4°C.

Other products e.g. gels may be extruded at temperatures above 0C, such as, ambient temperature.

The number of streams that may be used is not limited, but oooo would typically be around 2-10, e.g. 2-6. Each component may be known as a food product in its' own right e.g .:oeoi separate streams of ice-cream and jelly.

Step (ii) In the second step the diameter of the product in the filled flexible tube is restricted by passing it through a diameter-restricting means either during or immediately after step (i) For 'immediately after', the restriction occurs directly after (co)extrusion e.g. the 'diameter-restricting means' F3210 (C) -8abutts the extrusion means e.g. nozzle. For 'during', if the 'diameter-restricting means' fits at least partially, onto, or over, the extrusion means.

Any suitable diameter-restricting means may be used.

Preferably said means is either a pipe having an equal or larger diameter than the (total) diameter of the extruded streams and having a smaller diameter than the flexible tube, or, it is a shaped roller. The roller is shaped and positioned such that it provides the desired diameter restricting effect.

o o oo Alternatively the diameter-restricting means may be an 'louter' means used around the flexible tube of sachet material to prevent excess pressure overfilling the tube. eg a pipe fitted around the flexible tube. The pipe in the S. preceding paragraph may be used in addition to the 'outer' means to provide a double pipe restricting-means 9. arrangement.

Steps and (ii) may be in practice simultaneous, or, step r may proceed step (ii) Step (iii) Once the flexible tube has been filled with the stream(s) at least one further seal is made in the sachet.

Pressure is applied across the filled tube from step (ii) to produce a sealing area. The pressure may be applied across the width of the tube perpendicular to the sides of the tube, or, slightly offset to the perpendicular and is usually applied in an orientation other than with, or F3210 (C) 9 opposite to, the direction of movement of the flexible tube.

The sealing area is substantially, preferably totally, free of the product. The pressure may be applied by e.g. via a bar or roller or, simply by the action of bringing the parts of the flexible tube together to form a sealing area which is then sealed. Preferably pressure is applied positively to produce a good seal eg by a bar or roller.

The sealing area is sealed by any suitable means to produce a leading sealed edge. Sealing methods include heat and/or .pressure treatments, e.g. crimping, or less preferably ~adhesive applied to the edges to be sealed. If pressure is oo.. not applied to produce sealing area a lower quality seal is produced.

The leading edge is usually cut by suitable means.

Step (iv) ce• To produce the flexible sachet the following edge of the sachet is sealed. The sealing steps of step (iii) are repeated. Step (iv) results in either a single sachet being formed, or, a plurality of sachets joined together in a 'string' There may be more than three seals in the sachet depending upon the complexity of the sachet shape. However the sachet will generally have a seal at each end and along its' length.

Usually both the leading and following sealed edges are cut, to form an individual sachet. Alternatively a plurality of F3210 (C) 10 sachets joined together may be produced by cutting the first leading seal and the ultimate following seal.

Products Any suitable food products or components may be used in the sachet provided they can be extruded without suffering appreciable loss of quality, stability, appearance etc..

o 1 0 The food product filled into the flexible tube may be a preformed food product e.g. a single water ice composition.

o Alternatively two or more streams of food product components may be extruded, preferably co-extruded, to form the food product in the sachet, e.g. where the food product is a 15 'striped' (water ice) product with one component stream producing one stripe and another component stream(s) producing another stripe(s).

Preferably the food product is a confectionery product. It 20 is especially preferred that where two or more streams of

S

components are extruded these remain as discrete 'streams' in the final packaged food product. Optically distinct streams, especially co-continuous streams, are preferred e.g. strips, zig-zags, weave patterns etc.

Colourings or differences in transparency or texture may be used to make the streams optically distinct.

Alternatively the streams may be different in terms of flavour complimentary flavours such as strawberries and cream etc.). In this case the streams are not necessarily optically distinct.

F3210 (C) 11 It is preferred if the packaged food product is frozen to produce a frozen food product, such as, a frozen confectionery product e.g. water ices, granitas, ice-creams, sorbets, sherbet, frozen yoghurts, ice milk and frozen custards, creams, frozen fruit purees, milk based desserts and mixtures thereof.

Preferably the level of solids in the frozen confection sugar, fat, flavouring, milk solids etc.) is more than 1. 0 4 wt%, preferably more than 10 wt%, more preferred from to 70 wt%.

Sachet Material The sachet may be made of any suitable food grade packaging material e.g. paper, waxed paper, plastic etc. Preferably transparent plastic material is used. Very good results can be obtained by using e.g. plastics such as low density polyethylene and oriented polypropylene.

The sachet may conveniently be made of one or more sheets of flexible material which are sealed to form the sachet e.g.

by sealing them together at the edges to form a sachet or one sheet(s) may be folded and then sealed at the edges to form a sachet. However the single length of material being folded as described above is preferred.

In a preferred embodiment of the invention the sachet is rectangular or is sausage-shaped. The sachet may consist of a tube of flexible material which is sealed along two sides, whereby the seals are perpendicular with respect to each other so the resulting sachet has a tetrahedral shape.

F3210 (C) 12 Preferably the sachet has an internal volume of 5-5000 ml, more preferred 10-200 ml, most preferred 20-100 ml. Very preferred is a rectangular filled sachet wherein the length of the sachet is at least 2 times the diameter. This form allows optimum rapid freezing, and easy removal of the product from the sachet.

Apparatus 1 0 The apparatus used to carry out the process of the invention has a sachet filling means and sachet sealing means and a *food product diameter-restricting means in contact with, or adjacent to, the filling means and prior to the sealing means. Typically the filling means is an extrusion nozzle.

S 15 Typically the sealing means is a set of rollers or bar or combination thereof.

A suitable apparatus for carrying out the invention is a modified flow-wrap apparatus, modified so that the diameter- 20 restricting means is placed in contact with, or adjacent to the sachet filling means eg extrusion nozzle. The filling of the sachet preferably happens continuously. Typically to form a flexible tube and the wheels to pull the material through the apparatus and a means to heat and press the film together are provided.

The diameter restricting means is preferably an insulated pipe with a diameter is referred to herein above. As the process of the invention may be used in combination with any suitable food product packaging apparatus only the parts of the apparatus relevant to the claimed process are shown in the figures.

F3210 (C) 13 An example of the apparatus used to carry out the process of the invention will now be given to illustrate, but not limit, the invention referring to the accompanying diagramatic drawing in which figures 1 and 2 show a side cross section of a device which may be used.

Figure 1 shows an extrusion nozzle through which the food product is extruded and passes into the food- .oo.

product diameter restricting means pipe and emerges into 10 a flexible tube formed by the flexible sachet material (6) A sealing area is produced by the action of the rollers being forced together and a seal produced. The seal is then cut by the bringing together of cutting blades to produce the sachet.

S Figure 2 is a modification of Figure 1 where the pipe is shown outside the flexible tube The sealing rollers and the cutting blades are not shown in Figure 2 but could also be present.

F3210(C) 14 Examples The present invention will be further illustrated by the following non-limiting examples. Further examples within the scope of the present invention will be apparent to the person skilled in the art.

Example 1 A single stream water ice packaged product 10 A sucrose aqueous solution was prepared by mixing: a 15 a o Sucrose Citric Acid Locust Bean Gum Carageenan Gum Flavourings Colourings Water by weight 18.0 0.2 0.25 0.02 0.45 0.0035 81.0765 The sucrose solution was cooled in a freezer unit to between 0 C to -3.5 °C to produce a water ice 'slush' composition from where it was fed continuously into a sachet filling apparatus (a flow wrap apparatus).

A sealed flexible tube was continuously formed by the flow wrap apparatus, immediately prior to a filling step, by folding a length of clear plastic sachet material so that the outer edges were brought into contact and a 'fin' seal produced along the length of the material and sealed by heat and driven rollers to produce the moving flexible tube. The flexible tube moved over an extrusion nozzle of the apparatus and then over an insulated pipe attached thereto F3210 (C) 15 so the tube formed a covering over the extruded product in the insulated pipe and the pipe.

A stream of the water ice composition was continuously extruded at a temperature of -2.7 0 C through the nozzle into the insulated pipe fitted thereto. The extruded stream moved down the pipe and emerged out into the moving sealed flexible tube. The level of ice as the stream was extruded was between 30 and 45% by weight of the stream.

The extruded product, immediately after extrusion, had a diameter of approximately 25mm. The insulated pipe had an internal diameter of 25mm. The diameter of the stream was restricted by the insulated pipe diameter during filling of S 15 the flexible tube through the pipe.

The insulated pipe was very effective in stopping ice and condensation forming on the outside of it during the filling of the sachet.

The filled flexible tube was moved, by a pulling mechanism, away from the insulated pipe towards a sachet sealing area.

The tube was sealed at the forward edge by applying pressure from two rotating eccentric bars heated to about 1800C across the filled tube to force the product away from the sealing area and at the same time forming the front sealed sachet end.

The sachet end-seal was formed in the same way to form a filled sachet containing a water ice 'slush'.

F3210 (C) 16 The seals were cut to provide individual sachets which were frozen to produce a packaged frozen confectionery water ice product.

The frozen product exhibited good physical properties during frozen storage, retained the sachet integrity and did not exhibit unacceptable expansion.

Example 2 A double stream water ice packaged product The basic formulation and process in example 1 was repeated S' but in two formulation batches contrasting colours and flavours were used to manufacture a product having two distinct layers in terms of colour and flavour. Each batch was a component stream of the product.

The different batches were cooled in separate freezers and a stream of each batch was pumped continuously to a sachet filling apparatus (again a flow wrap apparatus). Each 20 stream was fed into a rotary nozzle and the steams coextruded simultaneously and continuously. The level of ice in the slush during extrusion was as for Example i.

An individual sachet containing a "striped appearance" water ice product was obtained without appreciable mixing of the stripes. The sachets were frozen to produce a packaged frozen stripped appearance water ice product.

The frozen product exhibited good physical properties during frozen storage, retained sachet integrity and did not exhibit unacceptable expansion.

F3210 (C) 17 Example 3 a single stream ice cream packaged product An ice cream mixture having the following composition was prepared.

by weight Skimmed milk powder 5.75 Skimmed milk replacer 1.00 Whey powder 2.50 10 Sugar 13.50 Glucose syrup 2.50 Coconut oil 9.90 Stabiliser/emulsifier mix 0.27 Water, flavouring colouring balance 0 O (Flavouring and colouring were added at appropriate levels).

The ice cream mixture was prepared in a conventional manner and filled into the sachets as a 'slush' as according to the process in Example 1. The amount of ice in the ice cream 20 mixture when it was extruded was between 30 to 45% by weight.

Individual sachets were frozen to produce a packaged frozen ice cream product.

The frozen product exhibited good physical properties during frozen storage, retained sachet integrity and did not exhibit unacceptable expansion.

F3210 (C) 18 Example 4 A gel filled packaged food product A gel filled package was produced with the following filling composition: by weight a a Carageenan/Locust bean gum mixture Citric acid Strawberry puree and flavour Colour Sugar Water 0.6 20.12 0.0025 23.0 balance It exhibited the same storage properties as for the other examples.

Comparative Example Example 2 was repeated, but, without the (insulating), diameter restricting pipe.

Without the use of the insulating pipe to restrict the diameter of the products upon storage, they expanded within the sachets to an unacceptable extent. The sachet integrity was not maintained. The insulating pipe used to restrict the diameter of the product during filing allows a packaged frozen product to be obtained that does not destroy the integrity of the package upon storage.

Claims (16)

1. A process for packaging a food product in a flexible sachet comprising the steps; i) introducing at least one stream of extrudable edible material into a flexible tube of sachet material, S.. 10 9@ 15 S S S ii) restricting the diameter of the edible material in the tube by passing the material through a diameter restricting means either during or immediately after step Ci), iii) applying pressure across the tube to produce a se'aling area, which is substantially free of the edible material, and sealing to produce a leading sealed edge, iv) repeating step (iii) to produce a following sealed edge to form the flexible sachet, wherein at least one stream of extrudable edible material is in a slush form or a gel form when introduced into the tube.

2. A process according to Claim 1 wherein the flexible tube moves continuously and/or the edible product is introduced continuously during step (i)

3. A process according to either Claim 1 or 2 wherein two or more streams of extrudable edible material are introduced into the flexible tube and remain as discrete streams in the packaged food product, preferably optically distinct co- continuous streams. F3210(C) 20

4. A process according to any one of the preceding claims wherein said slush contains 10 to 60% by weight of ice based upon the weight of the respective stream when introduced. A process according to any one of the preceding claims wherein at least one stream is in a slush form, and, at least one stream is in a gel form when introduced.

6. A process according to any one of the preceding claims wherein all streams are in a slush form.

7. A process according to any one of the preceding claims S 15 wherein at least two streams are introduced into the flexible tube by co-extrusion.

8. A process according to any one of the preceding claims wherein the flexible tube in step is formed immediately 20 prior to, or during, step by continuously sealing a moving length of sachet material along adjacent edges lying in the direction of movement of the material.

9. A process according to any one of the preceding claims wherein said diameter restricting means is either a pipe having an equal or larger diameter than that of the total diameter of the extruded streams and a smaller diameter than said flexible tube, or, is a shaped roller.

10. A process according to any one of the preceding claims wherein the leading and/or following sealed edge is cut to form an individual sachet or a plurality of sachets joined together. F32 10 (C) -21

11. A process according to any one of the preceding claims wherein said packaged food product end is frozen after step (iv) to produce a frozen product.

12. A process according to any preceding claim wherein the food product is a confectionery product.

13. A flexible sachet containing a food product packaged by a10 the process of any one of the preceding claims.

14. A flexible sachet according to Claim 13 wherein the cofood or product is a foe confectionery product selected from water ice, granita, ice cream, sorbet, frozen yoghurt, frozen fruit puree or mixture thereof.

16. Apparatus for the filling and production of a flexible sachet containing a food product, the apparatus having a sachet filling means and sachet sealing means, and a food product diameter restricting means in contact with, or adjacent to, the filling means and prior to the sealing means.

17. Apparatus according to Claim 16 wherein the food product diameter restricting means is a tube or shaped rollers in contact with, or adjacent to, the sachet filling means.

18. Apparatus according to either Claim 16 or 17 which is a flow-wrap apparatus. DATED Signe r a d on behalf, UNILEVER PLC by s't rali imited B. F. JONES, pany Se retary