U.S. patent application number 10/582720 was filed with the patent office on 2007-07-05 for method of packaging foodstuffs and container packed by said method.
Invention is credited to Kenneth Parry, Shilen Thakrar, Lesley Wood.
Application Number | 20070154600 10/582720 |
Document ID | / |
Family ID | 32011963 |
Filed Date | 2007-07-05 |
United States Patent
Application |
20070154600 |
Kind Code |
A1 |
Parry; Kenneth ; et
al. |
July 5, 2007 |
Method of packaging foodstuffs and container packed by said
method
Abstract
The method involves purging of the oxygen content from within
the interior of a flexible-walled container by flushing it with an
inert gas such as nitrogen. Ideally, the residual oxygen content
should be less that 2%, or most preferably, less than 1%. The
flushing step may be implemented before, during or after
introduction of the foodstuff dependant upon whether the foodstuff
is in solid or liquid form, or a mixture of both. After introducing
the foodstuff and before sealing, the container is inflated with
nitrogen gas and may optionally be subsequently squeezed to remove
a selected volume of nitrogen gas. Where discrete pieces of a
foodstuff have a tendency to agglomerate during packaging,
transport and storage, a higher volume of nitrogen is retained
within the container after sealing to counter this effect and
ensure that the product is more appealing to the consumer.
Inventors: |
Parry; Kenneth; (Essex,
GB) ; Wood; Lesley; (Essex, GB) ; Thakrar;
Shilen; (Essex, GB) |
Correspondence
Address: |
DRINKER BIDDLE & REATH;ATTN: INTELLECTUAL PROPERTY GROUP
ONE LOGAN SQUARE
18TH AND CHERRY STREETS
PHILADELPHIA
PA
19103-6996
US
|
Family ID: |
32011963 |
Appl. No.: |
10/582720 |
Filed: |
February 16, 2005 |
PCT Filed: |
February 16, 2005 |
PCT NO: |
PCT/GB05/00532 |
371 Date: |
June 12, 2006 |
Current U.S.
Class: |
426/118 |
Current CPC
Class: |
B65B 31/042 20130101;
A23B 9/18 20130101; A23L 3/3409 20130101; B65B 25/001 20130101;
B65B 31/04 20130101 |
Class at
Publication: |
426/118 |
International
Class: |
B65D 81/20 20060101
B65D081/20 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 16, 2004 |
GB |
0403365.0 |
Claims
1-25. (canceled)
26. A method of filling a flexible-walled container comprising the
steps of: (i) purging substantially all oxygen from the interior of
the container by introducing an inert gas; (ii) introducing a
foodstuff into the container; (iii) over-inflating the container
with inert gas beyond a desired volume; (iv) subsequently removing
a selected volume of the inert gas from the container to leave a
selected volume remaining in the container; and (v) sealing the
container.
27. A method as claimed in claim 26, wherein the step of
introducing a foodstuff into the container is preceded by deploying
the container from a folded to an unfolded configuration.
28. A method as claimed in claim 27 wherein the step of deploying
the container from a folded to an unfolded configuration is
achieved by means of gas inflation.
29. A method as claimed in claim 26, wherein, if the introduced
foodstuff is substantially entirely solid in state, the step of
purging substantially all oxygen from the interior of the container
is initiated before the step of introducing the solid foodstuff
into the container.
30. A method as claimed in claim 26, wherein, if the introduced
foodstuff is substantially entirely solid in state, the steps of
purging substantially all oxygen from the interior of the container
and introducing the solid foodstuff into the container are
performed concurrently.
31. A method as claimed in claim 26, wherein, if the introduced
foodstuff is substantially entirely liquid in state, the step of
purging substantially all oxygen from the interior of the container
is initiated after the step of introducing the liquid foodstuff
into the container.
32. A method as claimed in claim 26, wherein, the step of
introducing a foodstuff into the container involves the
introduction of a substantially solid foodstuff followed by the
introduction of a substantially liquid foodstuff; and wherein the
step of purging substantially all oxygen from the interior of the
container is ceased after the step of introducing the substantially
solid foodstuff into the container.
33. A method as claimed in claim 29, wherein the container is
inflated by an inert gas after introduction of the substantially
solid foodstuff.
34. A method as claimed in claim 31, wherein the container is
inflated by an inert gas after introduction of the substantially
liquid foodstuff.
35. A method as claimed in claim 33, wherein the inert gas is
introduced into the container by gas introduction means whilst the
flexible wall of the open end of the container is engaged tightly
against the gas introduction means.
36. A method as claimed in claim 35, wherein the gas introduction
means is a nozzle with a substantially flat opening.
37. A method as claimed in claim 26, wherein the selected volume is
removed by mechanical squeezing of the flexible wall of the
container.
38. A method as claimed claim 26, wherein the container is sealed
by means of heat sealing.
39. A method as claimed in claim 26, wherein the volume of inert
gas remaining within the container is selected to reduce
agglomeration of discrete pieces of foodstuff.
40. A method as claimed in claim 26, wherein the foodstuff is
cereal based.
41. A method as claimed in claim 40, wherein the cereal is selected
from the group consisting of rice, couscous, wild rice, barley,
wheat, oats, rye, millet and maize.
42. A method as claimed in claim 26, wherein the flexible-walled
container is a plastics pouch.
43. A method as claimed in claim 26, wherein the inert gas is
selected from the group consisting of nitrogen, carbon dioxide,
helium, argon, neon and xenon.
44. A method as claimed in claim 26, wherein oxygen gas forms less
than 2% of the volume of gas within the container.
45. A method as claimed in claim 26, wherein oxygen gas forms less
than 1% of the volume of gas within the container.
46. A flexible-walled container filled by the method of claim 26.
Description
[0001] The present invention relates to a method of packaging
foodstuffs and particularly, but not exclusively, to a method of
packaging cereal based foodstuffs within flexible-walled
containers.
[0002] Modified Atmosphere Packaging (MAP) of food products in a
variety of pack formats and materials is a longstanding technique
used to reduce the atmospheric air, and in particular, oxygen
content within a sealed pack. By reducing the oxygen content of a
sealed pack, the shelf life of a product can be significantly
increased by delaying the onset of oxidative rancidity,
particularly in products containing oils.
[0003] The availability of gusseted plastics laminate and foil
pouches with appropriate barrier properties has enabled the
development of Pre-Cooked Ambient (PCA) products. Suitable pouches
can (i) withstand conventional full sterilisation retort processes;
(ii) retain very low oxygen and moisture permeability after the
retort process; and (iii) in the case of plastics laminate pouches,
allow foodstuffs to be reheated within their packaging in a
microwave oven. Many foodstuffs such as rice, noodles, pasta,
sauces and pet food containing small quantities of oil currently
use MAP and consequently benefit from ambient shelf lives of 12-18
months or more.
[0004] The MAP process involves filling the pouches with a
foodstuff and flushing the pouches with inert gases (such as
nitrogen and carbon dioxide) to reduce their oxygen content. The
inert gas or gas mixture inhibits proliferation of some
micro-organisms (moulds and bacteria) with no significant chemical
alteration of the product. The pouches are then mechanically
squeezed to remove substantially all of the gas mixture and then
sealed to achieve a residual oxygen content of typically below 2%
and ideally below 1%. After sealing, the pouch is subjected to the
full retort sterilisation process.
[0005] In the packaging of rice, noodles, pasta and related recipe
products (an example of which is egg fried rice containing discrete
pieces of scrambled egg and peas), the purging of gases from within
a pouch during the MAP process results in the compression and
agglomeration of the foodstuff. Using rice as an example,
agglomeration of the separate grains means that the product suffers
in a presentational sense. For example, rice grains often become
broken and therefore unappealing to the consumer.
[0006] According to the present invention there is provided a
method of filling a flexible-walled container comprising the steps
of: [0007] (i) purging substantially all oxygen from the interior
of the container by introducing an inert gas; [0008] (ii)
introducing a foodstuff into the container; and [0009] (iii)
sealing the container.
[0010] Preferably, the step of introducing a foodstuff into the
container is preceded by deploying the container from a folded to
an unfolded configuration.
[0011] Preferably, the step of deploying the container from a
folded to an unfolded configuration is achieved by means of gas
inflation.
[0012] Preferably, if the introduced foodstuff is substantially
entirely solid in state, the step of purging substantially all
oxygen from the interior of the container is initiated before the
step of introducing the solid foodstuff into the container.
[0013] Alternatively, if the introduced foodstuff is substantially
entirely solid in state, the steps of purging substantially all
oxygen from the interior of the container and introducing the solid
foodstuff into the container are performed concurrently.
[0014] Preferably, if the introduced foodstuff is substantially
entirely liquid in state, the step of purging substantially all
oxygen from the interior of the container is initiated after the
step of introducing the liquid foodstuff into the container.
[0015] Preferably, if the step of introducing a foodstuff into the
container involves the introduction of a substantially solid
foodstuff followed by the introduction of a substantially liquid
foodstuff, the step of purging substantially all oxygen from the
interior of the container is ceased after the step of introducing
the substantially solid foodstuff into the container.
[0016] Preferably, the container is inflated by an inert gas after
introduction of the substantially solid foodstuff.
[0017] Alternatively, the container is inflated by an inert gas
after introduction of the substantially liquid foodstuff.
[0018] Preferably, the inert gas is introduced into the container
by gas introduction means whilst the flexible wall of the open end
of the container is engaged tightly against the gas introduction
means.
[0019] Preferably, the gas introduction means is a nozzle with a
substantially flat opening.
[0020] Preferably, the container is inflated to a desired
volume.
[0021] Alternatively, the container is over-inflated beyond a
desired volume.
[0022] Preferably, a selected volume of the inert gas is
subsequently removed from within the container.
[0023] Preferably, the selected volume is removed by mechanical
squeezing of the flexible wall of the container.
[0024] Preferably, the step of sealing the container is performed
whilst the container is at least partially inflated to thereby
retain a selected volume of inert gas therein.
[0025] Preferably, the container is sealed by means of heat
sealing.
[0026] Preferably, the volume of inert gas remaining within the
container is selected to reduce agglomeration of discrete pieces of
foodstuff.
[0027] Preferably, the foodstuff is cereal based.
[0028] Preferably, the cereal is selected from the group consisting
of rice, couscous, wild rice, barley, wheat, oats, rye, millet and
maize.
[0029] Preferably, the flexible-walled container is a plastics
pouch.
[0030] Preferably, the inert gas is selected from the group
consisting of nitrogen, carbon dioxide, helium, argon, neon and
xenon.
[0031] Preferably, oxygen gas forms less than 2% of the volume of
gas within the container.
[0032] Most preferably, oxygen gas forms less than 1% of the volume
of gas within the container.
[0033] According to a second aspect of the present invention there
is provided a flexible-walled container filled by the method of any
of claims 1 to 22.
[0034] Embodiments of the present invention will now be described,
by way of example only, with reference to the following drawings in
which:
[0035] FIG. 1 is a flow diagram showing the various steps in the
packaging method of the present invention; and
[0036] FIG. 2 is a table showing comparative characteristics of
conventional pouches filled using (i) a conventional filling
method; and (ii) the filling method of the present invention.
[0037] FIG. 1 outlines the various production line stages involved
in implementing the method of filling pouches with a foodstuff.
[0038] Step 1: The first stage involves picking up and holding a
gusseted pouch at its top corners in a conventional manner.
Throughout the description, the terms `pouch` and `container` are
interchangeable. At this stage, the gusset at the base of the pouch
is in a folded state such that the whole pouch is in a
substantially flat configuration.
[0039] Step 2: The second stage involves mechanically separating
the walls of the unsealed end of the pouch by introducing a
substantially flat nozzle between the walls of its open end.
Nitrogen gas is then introduced between the walls to increase the
pressure within the pouch and thus deploy the pouch from a
substantially flat, folded configuration to an open unfolded
configuration.
[0040] Step 3: In the case of solid foodstuffs (or a mixture of
solids and liquids), these are introduced into the opened pouch
whilst the flow of nitrogen gas is maintained. This step ensures
that oxygen is flushed from the pouch before being trapped by the
foodstuff.
[0041] Step 4: If the foodstuff is entirely liquid (that is, not
wholly or partially solid) then no gas is introduced concurrently
with the foodstuff.
[0042] Step 5: Once the foodstuff (whether solid or liquid or both)
is introduced into the pouch, a flat nozzle is inserted into its
unsealed end. The walls of the unsealed end are pulled tight
against the nozzle, which then over-inflates the pouch with
nitrogen gas. Once the pouch is inflated, the flat nozzle is
removed from the pouch. It is to be understood that the by
over-inflate, it is meant that the pouch is inflated to a volume
which is greater than the desired volume.
[0043] Step 6: The pouch is squeezed in a controlled manner thus
removing a selected volume of nitrogen gas and reducing the overall
volume of the pouch from its over-inflated level to a desired
volume.
[0044] Alternatively, step 6 can be omitted such that the nitrogen
gas in step 5 is introduced into the pouch in a controlled manner
to inflate it to the desired volume, thus obviating the need for
the subsequent squeezing step. Once the pouch reaches the desired
volume, the unsealed end is heat sealed. The desired volume will
vary depending upon the amount and type of foodstuff being
packaged.
[0045] Step 7: The pouch then undergoes the full retort
sterilisation process wherein pouches are transferred into a
conventional overpressure retort and subjected to a thermal process
(either static or rotational) designed to achieve commercial
sterility appropriate to the nature of the contents (e.g. 6 minutes
at 121.degree. C. for rice products). Retort temperatures must not
exceed those specified by pouch manufacturers (normally 130.degree.
C.).
[0046] Neither, either or both of steps 2 and 3 may be employed in
combination with step 5 to achieve the required level of oxygen in
the sealed pouch which will be dependent on the nature of its
contents. Step 6 controls the final volume of the pouch.
[0047] Depending upon the nature of the pouch contents, either or
both of steps 3 and 4 are employed.
[0048] The aforementioned steps of the filling method introduce the
following important benefits and improvements. In view of the fact
that the pouch is sealed whilst retaining a selected volume of
nitrogen gas, the consumer's perception is that the partially
inflated pouch looks less rigid, less processed and has an overall
enhanced on-shelf appeal.
[0049] Moreover, in the conventional packaging process, pouches are
squeezed to remove substantially all gas to reduce the volume of
the pouches to that of their contents (i.e. vacuum packed).
Accordingly, when emptying conventionally packaged pouches the
contents are often lumpy and unappealing to the consumer. The
consumer is compelled to squeeze the pouch during or subsequent to
emptying its contents in order to break up and separate the
agglomerated foodstuff. Indeed some packs now contain instructions
to squeeze or break-up their contents before heating.
[0050] The partial inflation of the pouch achieved by the method of
the present invention reduces agglomeration of its contents and
promotes conditions wherein the foodstuff retains its original and
familiar characteristics. For example, in the case of rice, the
grains remain light, fluffy and separated. This is not only a
consumer preference but it also results in easier pouring of the
contents of the pouch.
[0051] FIG. 2 demonstrates the increased volume of pouches packaged
using the method of the present invention using the mean volume of
a conventionally packaged pouch as a reference. As discussed
previously, conventionally packaged pouches retain substantially no
gas after they are sealed and their volume is therefore
substantially equal to the volume of their contents.
[0052] The mean volume of pouches (of equal width/height and
containing the same weight/type of foodstuff) filled by the
packaging method of the present invention is, in the present
non-limiting example shown in FIG. 2, at least 11.4% greater than
that of conventionally packaged reference pouches.
[0053] Depending upon the nature of the foodstuff contained within
the partially inflated pouch, the increase in volume over that of
the reference is adapted to be at least 5%.
[0054] Such an increase in volume is beneficial in terms of
reducing the pressure applied to the foodstuff by the walls of the
container. Therefore, the likelihood of agglomeration of, for
example, cereal grains during the retort sterilisation process and
during storage, distribution and use is substantially reduced.
Maintaining separate free flowing cereal grains is a critical
quality parameter making the product more appealing to the consumer
and is absent in foodstuffs made using conventional processes.
[0055] Modifications and improvements may be made without departing
from the scope of the present invention. For example, the flexible
walled container may be made from a non-microwavable foil-based
material or from a material suitable for boil-in-bag cooking.
[0056] Although the inert gas is described above as being nitrogen,
other inert gases such as carbon dioxide, helium, argon, neon and
xenon could be used. Similarly, although the foodstuff has been
described in the foregoing description as rice, the method is
equally suitable for packaging other cereal based foodstuffs. For
example, couscous, wild rice, barley, wheat, oats, rye, millet,
maize etc.
[0057] Moreover, the method of filling the pouches may be performed
either manually or by automated means.
* * * * *