GB2321632A - Two-component packaged food products; closure caps - Google Patents

Abstract

The invention provides a two-component packaged food product comprising: a container (1) having substantially rigid walls (2) and an opening (3) for filling and emptying the container; a first food component (4) filling a first part of the container (1); a second food component (5) different from the first food component (4) filling a second part of the container separate from the first part, but with the second food component directly contacting the first food component; and a closure (7) secured to the opening of the container (1), characterised in that there is substantially no head space inside the container (1) between the container and closure and the first and second food components, whereby mixing of the food components when the container is agitated is reduced. Closure cap (7) has a compressible base portion (10), or an expansion chamber therein (12, Figure 3), to accommodate thermal expansion. Zero head space may be achieved by filling a head space with a semi-solid foam.

Description

TWO-COMPONENT PACKAGED FOOD PRODUCTS The present invention relates to two-component packaged food products and to containers and closures specifically adapted for the manufacture of such packaged food products.

The term "two-component packaged food product" as used herein refers to single packages containing two or more food components that are intended to be kept substantially separate during storage and distribution, and mixed only immediately before consumption. Preferably, the two components are used in different, sequential cooking steps.

A number of two-component packaging formats are known.

For example, it is known to provide thermo-formed plastic trays having two or more recesses for receiving different food products, the trays being sealed by a thermally bonded membrane across the top of the recesses. However,. it. is not practicable to thermoform glass containers into complex shapes of this type.

It is also known to provide packages in which two food products in semi-solid or gel form are packaged separately, but in physical contact in the same space. One example is the packaging of fruit yoghurts in which a carton has a layer of food jelly in the bottom, and a layer of yoghurt is provided on top of the fruit jelly. Another example is the packaging of peanut butter and jelly together in a single jar. Another example is the packaging of a pasta sauce with a layer of chopped olives or the like on top of the sauce in a glass jar, providing an attractive visual appearance. A drawback of such arrangements is that they rely on the gel/semi-solid consistency of at least one of the food products to inhibit mixing of the food products when the package is agitated during distribution.

Unfortunately, heat will liquefy such semi-solid foodstuffs and accordingly it is not possible to heat treat these packaged food products at the temperatures of 900C and above usually used to achieve shelf stability, since such heat treatment liquefies and mixes the components.

It would be especially desirable to provide a twocomponent sauce package, such as a two-component pasta sauce package. Such a package would preferably comprise a waterbased component containing water, tomato paste and other components, packaged together with an oil component, preferably containing chopped vegetables, such as onion or garlic, and/or meat. These components present in the oil component are fried initially to accomplish hightemperature flavour development and browning reactions required for vegetables and/or meat, prior to addition of the water-based component to complete preparation of the sauce.

It would also be especially desirable to provide a twocomponent cook-in sauce product, wherein the first component is a conventional meat or vegetable sauce and the second component is a marinade. In use, the marinade would be applied first to a food product, preferably meat. After the food product had been marinated, it would be mixed with the first sauce component for cooking.

Packaged sauces are generally required to be shelfstable, and thus require heat stabilisation and temperatures of 900C or above. Hitherto, no satisfactory means has existed for producing a shelf-stable two-component packaged liquid food product, such as a pasta sauce, in which at least one and preferably both components is a liquid, and which allows the first and second components to be used in combination for sequential food preparation steps.

Accordingly, it is an object of the present invention to provide such a two-component packaged food product.

It is a further object of the present invention to provide container closure assemblies and container closure caps specifically adapted for the production of such twocomponent packaged food products.

The present invention provides a two-component packaged food product comprising: a container having substantially rigid walls and an opening for filling and emptying the container; a first food component filling a first part of the container; a second food component different from the first food component filling a second part of the container separate from the first part and directly contacting the first food component; and a closure secured to the opening of the container, characterized in that there is substantially zero head space inside the container between the container and closure and the first and second food components, whereby mixing of the first and second food components when the container is agitated is reduced.

Preferably, at least one of the first and second food components is a fluids, more preferably they are both fluids. Preferably, the first food component is an aqueous fluid such as an aqueous tomato sauce, and the second food component is an edible oil-based fluid, such as vegetable oil, preferably containing chopped vegetables such as mushrooms, onions or garlic, and/or chopped meat. This enables the oil and chopped components therein to be stored and distributed raw, and cooked separately at high temperature immediately before use, thereby resulting in a sauce with greatly improved organoleptic properties. In other preferred embodiments, the second food component is a marinade.

Preferably, the container is a glass jar. Preferably, the first food component fills a lower part of a jar and the second food component fills the remaining upper part of the jar with the first and second food components in direct contact across the width of the jar. Preferably, the first and second food components are substantially mutually immiscible (e.g. one is lipid based and the other is water based) to inhibit diffusion or mixing of the two components.

The direct contact between the first and second food components provides an attractive visual appearance to the package, and avoids the expense and potential contamination hazard of providing a physical barrier between the two components.

A potential drawback of providing the first and second food components in direct physical contact in the package is that agitation of the package during distribution could cause physical mixing of the first and second food components prior to use. This potential problem is greatly reduced by substantially eliminating the head space that normally exists between the first and second food components and the walls of the container or the bottom of the closure cap that seals the container. In other words, the first or second food component inside the container substantially entirely fill the container and closure assembly. There is substantially no gas- or -vacuum-filled space between the fluid food contents and the container or closure. In other words, the interior of the container is substantially free of any pocket of gas or vacuum. Preferably, at least 99% of the internal volume of the container and closure assembly is filled by food components, more preferably at least 99.8% of the said volume is so filled, and most preferably at least 99.95% of the said volume is so filled.

The elimination of head space can be achieved by a variety of packaging techniques, in addition to careful control of the filling level of the container. For example, the closure may comprise release valve means to allow air to vent from inside the container during heat stabilization, together with space-filling means to replace the air gap when the food product cools following heat stabilization. The space-filling means preferably comprises a portion of the base portion of the closure cap that can undergo plastic deformation. The space-filling means can also comprise a layer of dry foam in the base of the cap that hydrates and expands in the heat stabilization step. The space-filling means can alternatively or additionally comprise a foam producing agent, such as calcium carbonate in one of the food components, that produces microscopic space-filling bubbles during the heat treatment step. An advantage of all such arrangements that rely on space-filling means inside the container is that, when the container is opened, there is a normal-looking headspace of 2-10 mm between the top of the container and the top of the food products inside. The "normal" headspace makes decanting of the container contents easier, and improves consumer acceptability.

In other preferred embodiments, one or both of the food components contains a dispersed foaming agent, such as calcium carbonate particles that react with acid present in the food components to form bubbles on heating. One or both of the food components also contains a gel forming agent such as pectin. The container is sealed in a conventional way, and then heat treated to stabilize the contents. The heat treatment results in the formation of a semi-solid foam that entirely fills and eliminates the head space of the package.

Preferably, the first and second food components are shelf-stable. That is to say, the first and second food components sealed inside the package are stable on storage at ambient temperature for a period of at least one month, and preferably at least three months. Preferably, the food product has been stabilised by heat treatment after sealing inside the package, preferably by treatment at a temperature of at least 90"C for at least five minutes. More preferably, the first and second food components have been pasteurized inside the package.

The absence of a low density pocket of air or vacuum inside the container makes it considerably less likely that gentle agitation of the container will result in mixing of the first and second food components. This is because the first and second food components themselves have generally similar densities, probably densities within about 10% of one another, so that agitating the container results in relatively weak mixing forces on the first and second components. The tendency of the first and second components to mix can be further reduced by providing one or both components in the form of a gel or paste or viscous liquid at ambient temperature.

In order to allow for thermal expansion of the first and second food components during normal thermal cycling at storage temperatures, and in particular during thermal stabilisation of the package, the two-component packaged food product according to the present invention having the closure secured thereto preferably comprises means to accommodate thermal expansion of the first and second food components. Preferably, this means is provided on the closure. Preferably, the means to accommodate thermal expansion comprises a compressible base portion of the closure. That is to say, the base of the closure facing the interior of the container presents a continuous surface to the food components therein, but can flex outwardly to accommodate expansion of the food components. The compressibility can be provided by a resilient diaphragm, or by a compressible foam body, or by a gas bag inside the base of the closure gap.

In alternative preferred embodiments, the means to accommodate thermal expansion comprises an expansion chamber in the cap, with the expansion chamber communicating with the inside of the container through a small aperture. The expansion chamber initially contains a pocket of gas but can be filled or partially filled by expansion of the food components from inside the container. The small aperture between the inside of the container and the expansion chamber means that the air or vacuum trapped in the expansion chamber does not cause mixing of the first and second food components when the package is agitated.

The present invention also provides a closure cap for use in a two-component packaged food product according to the invention, wherein the closure cap comprises means to accommodate thermal expansion selected from a compressible base portion as hereinbefore described and an expansion chamber in the closure cap as hereinbefore described.

The present invention also provides a container and closure assembly comprising a container and a closure cap in accordance with the invention, wherein the closure cap is adapted to be releasably secured to the container.

Specific embodiments of the present invention will now be described further, by way of example, with reference to the accompanying drawings, in which: Figure 1: shows a longitudinal sectional view through a two-component packaged food product according to the present invention; Figure 2: shows a detailed longitudinal sectional view of the closure cap region of the two-component package of Figure 1; Figure 3: shows a detailed sectional view similar to Figure 2, but through a second embodiment of the twocomponent packaged food product according to the present invention.

Referring to Figure 1, the two-component packaged food product shown in the drawing comprises a container 1, which is a glass jar having substantially rigid walls 2 and an opening 3 for filling and emptying the container. The interior of the container 1 is completely filled by a first food component 4 consisting of aqueous tomato sauce and a second food component 5 consisting of vegetable oil having pieces of onion suspended therein.

Referring to Figure 2, it can be seen that the opening 3 at the top of the container is closed and sealed by a closure cap 7. The closure cap 7 comprises a skirt portion 8 comprising thread portions for engagement with complementary thread portions on the outside of the container neck 3 to secure the cap 7 on the container neck 3 in twist-off fashion.

The closure cap 7 also comprises a base made up of an outer, rigid base portion 9 and an inner, flexible base portion 10. The flexible base portion 10 projects convexly into the interior of the container 1, thereby ensuring that there is substantially zero head space between the top of the oil component 5 inside the container and the inner base portion 10.

Thermal expansion of the contents of the container is accommodated by diaphragm-like outward flexing of the flexible base portion 10 of the closure 7 as shown by the dashed line in Figure 2.

A gas-filled cavity 11 is left between the inner and outer base portions 9,10. The cavity 11 may optionally contain a compressible foam or the like. The cavity 11 is preferably substantially sealed from the contents of the container.

It can thus be seen that this assembly enables a twocomponent food package to be produced with substantially zero head space, whilst enabling thermal expansion of the package contents during heat stabilisation after packing.

Referring to Figure 3, the alternative embodiment of the closure cap comprises a substantially rigid gas-filled expansion chamber 12 in the alternative cap 13, with apertures 14 to enable excess liquid food products from inside the container to expand into the expansion chamber during thermal stabilisation of the packaged two-component food product.

In use, the container and closure as hereinbefore described are filled with the two food components almost to the brim. The cap 7 or 13 is snap-fitted or screw-fitted onto the container neck, and the amount of food components in the container and dimensions of the cap are precisely adapted to fill substantially all of the remaining space inside the container thereby leaving zero head space. The two-component food package having the cap 7,13 sealed thereto is then heat sterilised, stored and distributed.

When the consumer wishes to consume the packaged sauce, it is merely necessary for the consumer to remove the cap, decant the oil and onions into a cooking vessel for high temperature cooking to develop suitable flavours, and then to add the tomato sauce from the bottom of the container.

Example 1 An alternative embodiment, in which zero headspace was achieved by filling the headspace with a semi-solid foam, was prepared as follows: To 1000g of a concentrated pasta sauce (comprising tomato puree, onions, garlic, herbs and 17% added water, at a natural pH of 3.95) were added 5 grams of low DE pectin.

(AMP 285 from SBI Benelux). Calcium carbonate was the raising agent used and dispersed into the mixture at a concentration of 0.35 gram per litre. The rest of the components of the sauce were assembled and a jar comprising 75% pasta sauce in the bottom layer and 25% olive oil and vegetable mix in the upper phase, was filled with a standard headspace of 1.5 cm and the jar was capped. The average fill temperature was 500C.

The sauce was pasteurised at 950C for a P0 of 5. During pasteurisation, CO2 formed by the reaction of the CaCO3 with the acid in the sauce, formed a mousse structure. The headspace in the jar is reduced to less than 3 mm. During cooling the mousse structure is set by the gelification of the pectin in the presence of calcium cations to form a stable structure.

Upon opening of the jar, the slight vacuum established in the jar during the warm filling is reduced and the mousse contracts slightly. This has the effect of settling the product to a headspace of around 1 cm. The reaction of the CaCO3 increases the pH of the sauce from 3.95 to 4.12.

The above embodiments have been described by way of example only. Many other embodiments falling within the scope of the accompanying claims will be apparent to the skilled reader.

Claims (13)

CLAIMS:

1. A two-component packaged food product comprising: a container having substantially rigid walls and an opening for filling and emptying the container; a first food component filling a first part of the container; a second food component different from the first food component filling a second part of the container separate from the first part and directly contacting the first food component; and a closure secured to the opening of the container, characterized in that there is substantially zero head space inside the container between the container and closure and the first and second food components, whereby mixing of the first and second food components when the container is agitated is reduced.

2. A two-component packaged food product according to Claim 1, wherein said first and second food components are both fluids.

3. A two-component packaged food product according to Claim 2, wherein the first food component is an aqueous fluid and the second food component is an edible oil-based fluid.

4. A two-component packaged food product according to Claim 2 or 3, wherein one or both of the fluids contains solid meat or vegetable pieces.

5. A two-component packaged food product according to any preceding claim, wherein the first and second food components are shelf-stable.

6. A two-component packaged food product according to Claim 5, wherein the first and second food components are pasteurized.

7. A two-component packaged food product according to any preceding claim, wherein the container having the closure secured thereto comprises means to accommodate thermal expansion of the first and second food components.

8. A two-component packaged food product according to Claim 7, wherein the means to accommodate thermal expansion comprises a compressible base portion of the closure.

9. A two-component packaged food product according to Claim 7, wherein the means to accommodate thermal expansion comprises an expansion chamber in the closure communicating with the inside of the container.

10. A two-component packaged food product according to any preceding claim, comprising a layer of a stable foam.

11. A closure cap for use in a two-component packaged food product according to Claim 8 or 9, wherein the closure cap comprises means to accommodate thermal expansion selected from a compressible base portion and an expansion chamber in the closure cap.

12. A container and closure assembly comprising a container and a closure cap according to Claim 10 adapted to be secured to the container.

13. A two-component packaged food product or a closure cap or a container and closure assembly substantially as hereinbefore described with reference to the accompanying drawings.