The present invention relates to snack food and to a method of manufacturing a plurality of snack food pieces.

There is a general need in the snack food art to provide consumers with new taste experiences associated with snack foods, for example which the consumer may perceive to be fresh and uniquely manufactured for that consumer.

Furthermore, there is a general need in the art to produce snack foods which have enhanced nutritional content, for example including wholegrain cereal ingredients and fruit and/or vegetable ingredients.

The present invention aims at least partially to meet those needs.

The present invention accordingly provides a snack food comprising an expanded cellular starch-based matrix which includes at least one wholegrain cereal component and at least one fruit and/or vegetable component, wherein the fruit and/or vegetable component comprises a pomace.

The present invention further provides a method of manufacturing a plurality of snack food pieces, the method comprising the steps of: i. providing a dough including at least one wholegrain cereal component and a fruit and/or vegetable component, wherein the fruit and/or vegetable component comprises a pomace;

ii. forming the dough into dough pieces;

iii. drying the dough pieces to form pellets; and

iv. cooking the pellets thereby causing the pellets to expand in volume and reduce in density to form snack food pieces comprising an expanded cellular starch- based matrix.

Preferred features of both of these aspects of the present invention are defined in the respective dependent claims.

The preferred embodiments of the present invention can provide a novel way to produce expanded snack food products which have a high fruit and/or vegetable content and with the fruit and/or vegetable component being sustainably sourced from pomace, for example apple and/or pear pomace.

In this specification, the term "pomace" means the solid remains of fruit and/or vegetable after pressing of the fruit to extract the fruit and/or vegetable juice therefrom; the pomace contains the skins, pulp and seeds, and optionally the stems, of the fruit and/or vegetable. The pomace is in the form of a solid pulp containing residual moisture from the fruit and/or vegetable.

Currently, pomace is mostly used commercially as a fodder for animals or as a fertilizer, or as a source of bioactive compounds, such as polyphenols, to be extracted therefrom. The present invention provides a sustainable and higher value use for pomace which can be incorporated into a snack food pellet to provide a snack food with high fruit and/or vegetable content. Even with a high pomace content the pellet can be reliably formed by sheeting a cohesive dough and then cooked, for example by air popping, to form a desirable expanded cellular snack food such as a chip. The snack food can also have high multigrain cereal content, and also high fibre content.

The preferred embodiments of the present invention employ pomace as a raw ingredient for snack food. The pomace is preferably initially thermally pretreated prior to incorporation into dough. The dough comprises at least one wholegrain cereal ingredient, a starch ingredient and water, although no additional water needs to be added because the water may be provided by the pomace and optionally the wholegrain cereal ingredient if that has been precooked, and other optional ingredients such as one or more vegetable oils and one or more flavourings, in particular salt. Therefore the moisture content of the pomace may be sufficient to form the dough without the addition of water to the dough. The dough is mixed to form a cohesive dough which is then sheeted, preferably by a sheeter-extruder. The dough sheet is cut into a plurality of dough sheet pieces. These pieces may have any desired shape and dimensions. The dough sheets are then dried to form pellets, typically to a moisture content of about 12 wt% based on the weight of the pellet.

The pellets are then cooked. During the cooking process the moisture in the pellets forms steam which causes the starch-matrix to expand to form a cellular structure, which is rigid. The cooking may be by air popping or by frying, although other cooking processes known to produce expanded snacks from pellets may be employed. The snack food pellets used in the present invention have a composition providing a propensity to expand when cooked. Furthermore, the physical characteristics, for example the dimensions, of the pellets before and after expansion, are compatible with their use in the selected cooking apparatus, for example an air popping cooking apparatus. The snack food pellets may be provided with other product design features to improve eating quality, for example particular flavourings or texturizing components.

The pellets comprise a starch-based matrix which is expandable when subjected to heat during a cooking process. The starch-based matrix comprises at least one starch, optionally a blend of starches or starch-containing components, which may be derived from a cereal, such as wheat, oats, barley, rice or maize, or a vegetable, optionally potato, or any mixture thereof. Other starch ingredients or sources may be used. The starch-based matrix may optionally various additional constituents such as colouring and/or flavouring components, sugars, raising agents, salts, emulsifiers, fats/oils, humectants, acids, bases, proteins, fibres, dairy ingredients, texture modifiers, acidity regulators or any combination thereof.

The composition of the pellets may incorporate one or more functional components, either within the body of the snack pellet, or applied as a coating to the snack pellet, to impart specific characteristics to the product. The composition may be formulated to improve the expansion characteristics, for example to achieve a higher expansion, providing a lighter texture to the consumer and/or a more consistent expansion. Other components may be added to provide a delivery of flavour, a delivery of colour or other visual effects, or a modification of texture, for example by providing a crunchy outer shell to the expanded piece. As is known in the art, the snack pellet may be formulated to provide a desired moisture content, salt content, starch content, etc.

A single layer pellet is typically provided. This may have any desired two-dimensional shape. The shape may be regular or irregular, and geometric, for example rectangular, or representational, for example representing a leaf or a fruit or vegetable. In one embodiment, the pellets are shaped to be substantially planar, which for the avoidance of doubt includes surfaces having some regular or irregular curvature.

Preferably, the starch-based matrix in the pellets is in the form of a layer which has a thickness of at least 0.5 mm, typically from 0.5 to 4 mm, most typically from 0.6 to 0.8 mm. The snack foods used in the present invention are preferably provided in a consumer acceptable retail format, for example a packaging such as a bag or carton, typically hermetically sealed, which is compatible with a retail sales environment.

Embodiments of the present invention will now be described by way of example only with reference to the accompanying drawings, in which:

Figure 1 schematically illustrates a perspective view of a snack food chip in accordance with an embodiment of the present invention; and

Figure 2 schematically illustrates a process flow of a method for producing a plurality of the snack food chips in accordance with an embodiment of the present invention.

Referring to Figure 1 of the accompanying drawings, a snack food chip 2 is shown. The snack food comprises an expanded cellular starch-based matrix which includes at least one wholegrain cereal component and at least one fruit and/or vegetable component. The fruit and/or vegetable component comprises a pomace.

The wholegrain cereal component is present in an amount of from 2 to 25 wt%, optionally from 5 to 20 wt%, further optionally from 7 to 15wt%, based on the weight of the snack food. Typically, the wholegrain cereal component includes at least one of wholegrain wheat, wholegrain barley, wholegrain maize, wholegrain buckwheat and wholegrain millet or any mixture of two or more thereof. In one particular example, the snack food comprises wholegrain buckwheat in an amount of from 3 to 8 wt%, based on the weight of the snack food, and wholegrain millet in an amount of from 3 to 8 wt%, based on the weight of the snack food.

Preferably, the starch-based matrix further includes a starch derivative or extract, optionally a vegetable or cereal starch derivative or extract, further optionally a potato starch derivative or extract. The starch may be native starch or pregelatinised starch or any mixture thereof. Typically, the starch derivative or extract is present in an amount of from 25 to 70 wt%, optionally from 30 to 60 wt%, further optionally from 35 to 50 wt%, based on the weight of the snack food.

In some embodiments, the pomace is fruit-based. Typically, the pomace includes or is apple pomace, pear pomace, orange pomace, blueberry pomace, raspberry pomace or strawberry pomace or any mixture of two or more thereof. In other embodiments, the pomace is vegetable-based. Typically, the pomace includes or is tomato pomace, beetroot pomace or carrot pomace or any mixture of two or more thereof.

Typically, the pomace is present in an amount of from 25 to 60 wt%, optionally from 35 to 55 wt , further optionally from 35 to 50 wt%, based on the weight of the snack food.

In some embodiments, the snack food is fried and the starch-based matrix further includes at least one vegetable oil, optionally sunflower oil, in an amount of from 15 to 30 wt% based on the weight of the snack food.

In other embodiments, the snack food has been cooked by other than frying, for example by air popping in which the snack food has been produced from dried pellets which have been expended in heated air. However, other non-frying cooking processes known to produce expanded snack foods from dried pellets may alternatively be used. In such non-frying embodiments, typically the starch-based matrix does not comprise any lipid component.

However, the snack food may be topically coated with at least one vegetable oil, for example sunflower oil. The topically coated vegetable oil may be present in an amount of from 1 to 12 wt%, optionally from 2 to 6 wt%, further optionally from 4 to 5 wt%, based on the weight of the snack food. The starch-based matrix may coated with a coating of at least one topical seasoning.

When a topical seasoning is applied, the topically coated vegetable oil may comprise a vehicle for the seasoning. The topical seasoning may include at least one fruit and/or vegetable seasoning, for example fruit and/or vegetable powder. The fruit and/or vegetable seasoning may be comprised of the same fruit and/or vegetable as the pomace, for example at least one of apple or pear seasoning. The topical seasoning may further includes a spice, for example cinnamon.

The starch-based matrix in the snack food typically has a water content to provide a water activity Aw of less than 1.0, optionally less than 0.8, further optionally less than 0.6.

A consumer portion of the snack food chips 2 may be packaged in a polymeric bag, typically having a metal foil layer, which is conventionally used to package snack food chips. The contents may be hermetically sealed within the bag, optionally within a controlled atmosphere, for example a low oxygen atmosphere, such as nitrogen. Referring to Figure 2 of the accompanying drawings, there is shown a process flow for the manufacture of a plurality of snack food chops as shown in Figure 1.

In a first step 10 of the method a dough is provided. The dough includes the at least one wholegrain cereal component the fruit and/or vegetable component which comprises a pomace as described above.

The wholegrain cereal component in the dough is present in an amount of from 5 to 25 wt%, optionally from 10 to 20 wt%, further optionally from 12 to 18 wt%, based on the weight of the dough. The wholegrain cereal component in the dough is present in an amount to provide in the snack food from 2 to 25 wt%, optionally from 5 to 20 wt%, further optionally from 7 to 15 wt%, based on the weight of the snack food, of the at least one wholegrain cereal component. As described above, wherein the wholegrain cereal component may include at least one of wholegrain wheat, wholegrain barley, wholegrain maize, wholegrain buckwheat and wholegrain millet or any mixture of two or more thereof. Typically, the dough comprises wholegrain buckwheat in an amount of from 5 to 10 wt%, based on the weight of the dough, and wholegrain millet in an amount of from 5 to 10 wt%, based on the weight of the dough.

Preferably, the at least one wholegrain cereal component in the dough has been pre-cooked. Typically, the pre-cooked wholegrain cereal component in the dough has a water content of from 40 to 80 wt%, optionally from 50 to 70 wt%, further optionally from 55 to 65 wt%, based on the weight of the at least one wholegrain cereal component.

The wholegrain cereal component in the dough may be present as a ground flour, although some or all of the wholegrain cereal component may be present as particles which are of sufficient dimensions to be visible to the naked eye in the snack food chip.

The dough preferably further includes a starch derivative or extract, optionally a vegetable or cereal starch derivative or extract, further optionally a potato starch derivative or extract. Typically, the starch derivative or extract in the dough is present in an amount to of 15 to 40 wt%, optionally from 20 to 30 wt%, based on the weight of the dough. In some embodiments, the starch derivative or extract in the dough comprises a mixture of from 5 to 15 wt% pregelatinised starch, optionally pregelatinised potato starch, and from 10 to 20 wt% native starch, optionally native potato starch, each amount being based on the weight of the dough. Preferably, the starch derivative or extract in the dough is present in an amount to provide in the snack food from 25 to 70 wt%, optionally from 30 to 60 wt%, further optionally from 35 to 50 wt%, based on the weight of the snack food, of the starch derivative or extract.

As described above, the pomace may be fruit-based and typically includes or is apple pomace, pear pomace, orange pomace, blueberry pomace, raspberry pomace or strawberry pomace or any mixture of two or more thereof. Alternatively, the pomace may be vegetable-based and typically includes or is tomato pomace, beetroot pomace or carrot pomace or any mixture of two or more thereof. Typically, the pomace comprises from 40 to 80 wt% water, optionally from 60 to 80 wt% water, further optionally from 65 to 75 wt% water, based on the weight of the pomace. In some embodiments, the pomace is present in the dough in an amount of from 40 to 80 wt%, optionally from 50 to 70 wt%, further optionally from 55 to 65 wt%, based on the weight of the dough. Accordingly, the pomace may be present in an amount to provide in the snack food from 25 to 60 wt , optionally from 35 to 55 wt%, further optionally from 35 to 50 wt%, based on the weight of the snack food, of the pomace.

The pomace fruit and/or vegetable component has been pre-treated by a heat treatment at a temperature of from 50 to 100 °C for a period of from 5 to 30 minutes, optionally at a temperature of from 60 to 80 °C for a period of from 10 to 20 minutes, further optionally at a temperature of from 65 to 75 °C for a period of from 12 to 18 minutes.

Typically, the dough does not comprise any lipid component.

In a second step 12 the dough is formed into dough pieces. Typically, the dough is sheeted to form a dough sheet which is cut into dough pieces. Preferably, the dough is extruded by an extruder to form the dough sheet. The extruder typically comprises a mixer to form the dough. The resultant dough pieces preferably have a water content of from greater than 15 to up to 30 wt%, optionally from 20 to 30 wt%, further optionally from 25 to 30 wt%, based on the weight of the dough.

Then, in a third step 14 the dough pieces are dried to form pellets, the dough pieces being dried to form pellets having a water content of from 8 to 15 wt%, optionally from 10 to 14 wt%, further optionally about 12 wt%, based on the weight of the pellets.

The pellet is formulated and structured to expand during the cooking process. Typical properties of pellets in accordance with the present invention which are well suited to expansion are (i) a starch composition with a high degree of gelatinisation and (ii) an open pellet structure to allow rapid thermal energy transfer from the pellet surface to the interior of the pellet.

Starch gelatinisation is dependent upon the relative amounts of amorphous and crystalline starch within the starch-based matrix of the pellet. These amounts may be measured using Fourier Transform Infrared Spectroscopy (FTIR), a technique known in the art. A higher proportion of amorphous starch generally corresponds with a generally higher expansion in the cooking conditions.

In some embodiments, the starch-based matrix includes a crystalline fraction and an amorphous fraction, wherein the weight ratio of the crystalline fraction to the amorphous fraction is from 0.15 to 0.67, optionally from 0.17 to 0.60. In some embodiments, the starch-based matrix includes a crystalline fraction and an amorphous fraction, and the amorphous fraction comprises from 50 to 90 wt%, optionally from 60 to 85 wt%, of the combination of the crystalline fraction and an amorphous fraction Such a high amorphous fraction can provide increased expansion of the pellet.

The starch-based matrix may be formulated so as to be adapted to expand by from 50 to 500 % when forming the expanded snack food piece.

The starch matrix can achieve the desired crystalline and amorphous fractions by providing a single starch-containing component or a blend of different starch components. A starch component having a high degree of amorphous starch can be a highly gelatinised starch produced by a preliminary cooking step.

Furthermore, in order to achieve expansion during cooking, it is important that the starch-based matrix in the pellet melts at the cooking temperature in order for the starch to be in the molten state and therefore capable of readily swelling at that temperature. The starch-based matrix in the pellet should have a melting temperature (Tm) which is lower than the temperature reached by the pellet through the cooking process.

Typically, the starch-based matrix has a melting temperature of from 50 to 70 °C, optionally from 50 to 60 °C.

The pellets are typically manufactured using an extruder, as generally known in the art of snack food manufacture. The pellets have a composition to provide a desired colour; flavour; starch; starch-containing ingredient; level of starch gelatinization; internal porosity; open volume; density; moisture content; and shape, or any combination of any two or more thereof. It is known generally how to control these parameters in the manufacture of snack food pellets.

The shape and dimensions of the pellets, together with the composition of the pellets which determines the degree of expansion of the pellet during cooking, primarily determine the shape and dimensions of the expanded snack food pieces produced from the pellets. The pellet may be shaped and dimensioned to provide any desired shape and dimensions to the resultant expanded snack food piece using shape and dimension selection techniques well known to those skilled in the snack food art.

In some embodiments, the pellets are adapted to form an expanded snack food piece having a volume which is from 50 to 500 % larger than the volume of the pellet.

In a fourth step 16 the pellets are cooked thereby causing the pellets to expand in volume and reduce in density to form snack food chips comprising an expanded cellular starch-based matrix.

In one embodiment, the pellets are cooked in heated air in a cooking apparatus comprising a cooking chamber defining a cooking cavity and a mechanism for directing heated air into the cavity. The heated air in the cavity cooks the dough pieces. The air is heated to a temperature of at least 150 °C, optionally from 200 to 350 °C, further optionally from 250 to 350 °C, yet further optionally from 275 to 325 °C. The dough pieces are typically cooked in the heated air for a period of from 3 to 30 seconds, optionally from 5 to 20 seconds, further optionally from 5 to 15 seconds, yet further optionally from 8 to 12 seconds.

It has particularly been found that providing a pellet thickness of from 0.6 to 0.8 mm achieves reliable expansion of the pellet during the air popping process when the pellet has the high pomace concentration employed to produce the snack foods of the invention.

In an alternative embodiment, the pellets are cooked by frying in vegetable oil.

In other embodiments, the pellets may be cooked by baking or microwaving.

After the cooking step, the expanded starch-based matrix has a water content to provide a water activity Aw of less than 1.0, optionally less than 0.8, further optionally less than 0.6. In the cooking method of a preferred embodiment of the present invention, hot air is used to cook and expand the pellet. Air is much less efficient at transferring thermal energy into the pellet interior than hot oil, which is the conventional medium for cooking pellets to form expanded snack food pieces. Consequently, in order to compensate for the reduced energy transfer from the hot air, the pellet is structured so as to be sufficiently thin in section so that the pellet presents a high surface area to allow heat energy to enter the pellet at a high level of thermal efficiency.

Such a structure may be achieved by providing that the smallest pellet dimension is less than a few millimetres. For simple pellet structures, for example sticks or substantially flat two- dimensional structures, the smallest pellet dimension can be determined by a simple measurement of the thinnest dimension. Other pellet structures can comprise a more complex perforated or lattice sheeted structure, often with multiple sheets layered on top of each other. In such cases, the thickness of thinnest strands within the perforated/lattice structure may be determined to constitute the smallest pellet dimension.

Typically, when the pellet, or the expanded snack food piece, is in the form of a three dimensional shape, preferably the pellet is structured to provide a substantially uniform exposure to the air flow throughout the pellet. This can provide a uniform expansion, and avoid the edges being burned or scorched and the middle of the pellet being unexpanded.

Preferably, the pellet shape and dimensions can provide that the heat transfer on outside surfaces, and if present on inside pellet surfaces, is substantially equal, so the expansion of the pellet tube is controlled and regular.

The pellet properties may be determined using reasonable trial and error to be utilisable in a cooking apparatus having a typical range for both the air flow velocity and the cooking temperature for such apparatus.

In a fifth step 18, which is a seasoning step, the snack food is topically coated with a coating of at least one topical seasoning, as described above with respect to the snack food chip of Figure 1.

The present invention will now be described further with reference to the following non- limiting Example.

Example 1 A dough was prepared having the following composition based on a wet mix dough with the wt% values being based on the weight of the wet mix dough: apple pomace 60 wt%, native potato starch 15 wt%, pregelatinised potato starch 10 wt , precooked wholegrain buckwheat 7 wt%, precooked wholegrain millet 7 wt%, salt 1 wt%. There was no added water; the moisture content of the dough was 20 to 30 wt% based on the weight of the dough, with the water content being provided by the pomace and the precooked wholegrain cereal ingredients.

The dough was formed into dough sheet pieces which were then dried to form pellets having a thickness of from 0.6 to 0.8 mm. The pellets had a water content of about 12 wt% based on the weight of the pellets.

The pellets were then air popped in heated air at a temperature of 300 °C for a period of 10 seconds.

The resultant snack food chips had the following composition based on a dry product basis with the wt% values being based on the weight of the final chip: apple pomace 39 wt%, native potato starch 26 wt%, pregelatinised potato starch 20 wt%, wholegrain buckwheat 6 wt , precooked wholegrain millet 6.77 wt%, salt 1.3 wt%. The snack food chip is illustrated in Figure 1.

Therefore in a particularly preferred embodiment of the present invention, in the snack food chip the wholegrain cereal component is present in an amount of from 5 to 20 wt% based on the weight of the snack food; the starch-based matrix includes a vegetable or cereal starch derivative or extract, optionally a potato starch derivative or extract, in an amount of from 35 to 50 wt%, based on the weight of the snack food; the pomace is fruit-based, typically apple and/or pear with a water content of from 60 to 80 % based on the weight of the pomace, and is present in an amount of from 35 to 55 wt% based on the weight of the snack food; the starch- based matrix preferably does not comprise any lipid component; and the snack food has been cooked by air popping of pellets having a thickness of from 0.6 to 0.8 mm and a water content of from 10 to 14 wt% based on the weight of the pellets, the air temperature being from 200 to 350 °C for a cooking period of from 5 to 20 seconds so that in the chip the starch-based matrix has a water activity Aw of less than 0.8. The pellets have been produced from a dough which has a water content of from greater than 15 to 30 wt% based on the weight of the dough, the starch derivative or extract in the dough is present in an amount of from 20 to 30 wt% based on the weight of the dough, the at least one wholegrain cereal component in the dough is present in an amount of from 10 to 20 wt%, based on the weight of the dough, the pomace comprises from 60 to 80 wt water, based on the weight of the pomace, and the pomace is present in the dough in an amount of from 50 to 70 wt%, based on the weight of the dough. Optionally, the at least one wholegrain cereal component in the dough has been pre-cooked and has a water content of from 40 to 80 wt%, based on the weight of the at least one wholegrain cereal component. Optionally, the pomace has been pre-treated by a heat treatment at a temperature of at a temperature of from 60 to 80 °C for a period of from 10 to 20 minutes, further optionally at a temperature of from 65 to 75 °C for a period of from 12 to 18 minutes.

Various other modifications to the present invention will be readily apparent to those skilled in the art.