WO1995011599A1

WO1995011599A1 - Snack product comprising a dough envelope and a filling based on crumbs, fat and starch

Info

Publication number: WO1995011599A1
Application number: PCT/GB1994/002376
Authority: WO
Inventors: Dave Nigel Clark; John Henry Leslie
Original assignee: United Biscuits (Uk) Limited
Priority date: 1993-10-29
Filing date: 1994-10-28
Publication date: 1995-05-04
Also published as: GB2298120A; GB9322268D0; GB9608495D0; GB2298120B; AU8000194A

Abstract

A baked snack product (1) comprises an envelope (2) and a filling, the filling (4) being the baked product of a mixture comprising a starch-based crumb material, a fat and a binding material, the envelope (2) having a moisture content of not more than 10 % by weight based on the weight of the envelope and the filling (4) having a moisture content of not more than 10 % by weight based on the total weight of the filling. The product may be made by forming a dough sheet, enclosing within an envelope made from the sheet a portion of a mixture of a starch-based crumb material, fat and binding material, and baking the envelope and the enclosed mixture. The baked product has an unusual and interesting texture.

Description

SNACK PRODUCT COMPRISING A DOUGH ENVELOPE AND A FILLING BASED ON CRUMBS, FAT AND STARCH

The present invention relates to snack products, and to methods for their manufacture.

In one type of snack product known previously, a dough material is co-extruded with a cream material to form a product consisting of an outer case and a cream filling. The cream filling typically consists largely of fat and, in the extruded product, has a smooth fatty texture. There is a need for a snack product having two portions of distinctly different textures, but of which a filling portion is of a less smooth, more interesting texture than the cream fillings previously used.

The present invention provides a snack product comprising an envelope of baked dough and a filling enclosed within said envelope, the filling comprising the baked product of a mixture of a starch-based crumb material, a fat and one or more binding materials selected from the group consisting of starches and starch derivatives, the envelope having a moisture content of not more than 10% by weight, based on the total weight of the envelope and the filling having a moisture content of not more than 10% by weight based on the total weight of the filling. It has been found that the presence of a starch-based crumb material in the filling gives the snack product an especially interesting texture. As already mentioned, the moisture contents of the filling and of the envelope do not exceed 10% by weight and, further, the filling is the baked product of a mixture comprising a starch-based crumb material, a fat and a binding material selected from starches and starch derivatives. As a result of the presence of the fat in the filling, which provides lubrication to the mouth on mastication, the product is perceived to have a moist filling but, because the moisture contents of the envelope and the filling are both relatively low, the product has good stability on storage at ambient tempera¬ ture. Further, only relatively small amounts of moisture are able to migrate between the envelope and filling after baking. Thus, even over long storage periods of, say, three months or more, the envelope and the filling can retain their distinct textures. In the case where the fat content of the filling is significantly greater than that of the envelope, the texture, as perceived by the consumer, is especially interesting.

The moisture contents of the envelope and filling are advantageously not more than 7.5%, and preferably not more than 5%, by weight based on the weight of the said envelope and the said filling, respectively. The filling may be the baked product produced on baking a mixture comprising from 20 to 180 parts by weight fat, advantageously at least 80 parts by weight fat, per 100 parts by weight starch-based crumb material. Preferably, the filling is a baked product of a mixture comprising from 80 to 160 parts by weight fat, and more preferably from 90 to 150 parts by weight fat, per 100 parts by weight starch-based crumb material. A satisfactory product may also be obtained if the filling is the baked product of a mixture comprising from 20 to 60 parts by weight fat per 100 parts by weight starch-based crumb material. In practice, the starch- based crumb material may itself contain fat derived from fat used in the manufacture of the crumb material. For example, there may advantageously be used starch-based crumb materials containing up to 15% fat, by weight, based on the total weight of crumb material. That fat, which will be substantially intimately bound within the crumb material, is not to be regarded as fat for the purposes of determining the proportion of fat in the mixture. On the other hand, if the crumb material contains fat which is not intimately bound within the crumb material (for example, where flavoured crumbs are used in wh flavouring has been added to the unflavoured crumb material by applying flavouring in an oil carrier) , it will be appreciated that that oil will constitute fat for the purposes of calculation of the ratio of fat to crumb material. Where flavour is added to the crumb material the flavour content of the flavoured crumb (not including the oil or other carrier) is advantageously less than 20%, more preferably less than 15% by weight of the flavoured crumb.

The starch-based crumb material may be an expanded cooked dough that is based on one or more starch materials. For example, the ingredient mix from which the crumb material is made may contain a starch selected from cereal starches, for example wheat starch, rice starch, corn starch (that is, maize starch) , and potato starch. For example, the ingredient mix may comprise one or more substances selected from wheat flour, potato flakes, potato powder, potato granules, corn flour and rice flour. Expansion of the said mix promotes the formation of pores in the crumb material. It is believed that the presence of a network of pores in the crumb material enhances the ability of the baked mixture to retain fat. The starch-based crumb material may be, for example, breadcrumbs. The term "breadcrumbs" is used herein to mean crumbs that have been made by producing a bread-type dough (that is, a dough comprising a cereal flour, water, and yeast or any other raising agent that may be used in the manufacture of bread) , baking the dough, whereupon expansion occurs, drying the baked dough and reducing it to particles. Advantageously, the starch-based crumb material is a material which has been obtained by extrusion cooking of starch or a starch-containing material. In an extrusion cooking process an ingredient mix containing the starch is heated in the extruder at elevated pressure. On leaving the extruder the extrudate expands because of the decrease in the pressure to which it is subjected.

Preferably, the starch-based crumb material has been obtained by extrusion cooking or baking a mixture of starches, for example, a mixture of two or more starches selected from cereal starches, for example, wheat starch, corn starch, rice starch, and potato starch, and drying and reducing to particles the cooked or baked mixture. The mixture of starches preferably consists predominantly of wheat starch. Starch-based crumb materials produced by extrusion cooking are commercially available and have previously been used, for example, in coatings for fish products and crumb coated snack foods, or in hydrated form as a filler material, for example, in sausages or chicken meat products. Those commercially available crumb materials may be used in the products of the present invention. The crumb material may advantageously be Japanese-style breadcrumbs, which may be flavoured or unflavoured. As indicated above, a flavoured starch-based crumb material may be used. Flavouring components may be added to the unflavoured crumb material, for example, in an oil carrier.

Advantageously, at least 80%, more preferably 90%, by weight of the unflavoured starch-based crumb material consists of particles having a size greater than 150μm, preferably greater than 200μm, especially greater than 250μm. Advantageously, at least 80%, more preferably at least 85%, especially at least 90% by weight of the unflavoured starch-based crumb material consists of particles having a size smaller than 2.4mm, preferably smaller than 2.0mm, especially smaller than 1.7mm.

At least a major proportion, for example at least 80%, or for example at least 85%, by weight of the unflavoured starch-based crumb material may consist of particles having a size in the range of, for example from 0.4 to 2.4mm. In a preferred embodiment, at least 80%, more preferably at least 85%, by weight of the unflavoured starch-based crumb material consists of particles having a size in the range of 150μm to 2mm, preferably 250μm to 1.7mm. It has been found to be particularly advantageous for the crumb material to contain particles of a range of different sizes within the said size ranges. The particle size range of the crumb material may conveniently be determined by the use of sieves (for example, conforming to British Standard No. 410) having apertures of the requisite dimensions. It has been found that when flavouring is added to the crumb material, for example with an oil carrier, the proportion of small particles in the material may increase. That increase occurs at least in part because of the mechanical action of mixing the crumb and flavour composition.

The word "fat" as used herein refers to edible fats and is to be understood as extending to edible oils that are liquid at room temperature. Examples of suitable fats are sunflower oil, hardened palm kernel oil and deodorised coconut fat.

In one aspect of the invention the fat is a fat that is solid at 20°C. In the case of snack products in which the fat is a fat that is solid at 20°C (referred to hereinafter as "a hard fat") there is, after baking, little or no migration of fat from the filling to the envelope on storage at ambient temperatures. Where the fat is a hard fat, it has been found in practice that, once the product has been cooled to room temperature after cooking, in general less than 10%, for example less than 5% fat, by weight based on the total weight of the fat in the filling, migrates from the filling to the envelope during storage at temperatures not exceeding 20°C for a period of 14 weeks. As a result, it is possible to obtain a snack product having a filling that is perceived to be moist in consequence of the presence of fat and an envelope that, in contrast, is perceived to be relatively dry and crisp. A fat that has a slip melting point (also known as "slip point") of from 24 to 37°C, for example 26 to 37°C may be used. As hard fat, there may advantageously be used a blend of two or more fats selected from vegetable oils and hydrogenated vegetable oils. Where one or more vegetable oils other than a hydrogenated vegetable oil are present in the hard fat, it is preferred for one or more hydrogenated vegetable oils to be present, the type of oil and the amount thereof being so selected that the blend has a slip melting point exceeding 20°C. It is possible, however, for one or more (unhydrogenated) vegetable oils to be used alone, the vegetable oils then preferably being so chosen that the blend has a slip melting point exceeding 20°C.

According to another aspect of the invention, a fat having a slip melting point of not more than 20°C may be used. The use of such a fat is advantageous in that the resulting product has good mouthfeel, and is perceived by the consumer to have a more pleasant texture.

Advantageously, the fat has a slip melting point of from 10 to 20"C, for example, about 18°C. Advantageously, the fat is a blend of two or more fats, for example, of two or more fats selected from vegetable oils and hydrogenated vegetable oils, the components of the blend and their relative amounts being so chosen that the slip melting point of the blend is not more than 20°C. Preferably, where the fat has a slip melting point that is not more than 20°C, the fat is so selected, or where the fat is a mixture of two or more fats the components of the mixture are so selected, that a substantial proportion, for example, at least a major proportion of the fat remains solid at 18°C. The fat may be a hardened oil comprising a blend of rapeseed and palm oils. The binding material may be any starch or starch derivative that will bind components of the filling.

The binding material may comprise a pregelatinised starch. Examples of suitable pregelatinised starches are pregelatinised tapioca, pregelatinised potato starch and pregelatinised corn starch. The binding material may comprise a starch derivative, for example maltodextrin. The binding material may comprise a mixture of two or more starches and/or starch derivatives.

Advantageously, an ungelatinised starch is used as the binding material. As the ungelatinised starch there may be used any ungelatinised starch that, under the baking conditions, will gelatinise at least partially, thus giving added coherence to the structure of the filling. Where, as is preferred, the moisture content of the fat-containing mixture is below 20% by weight based on the total weight of said mixture, the starch should not constitute a very large proportion of the mixture, as the degree of gelatinisation that is possible is limited by the amount of available water, and it is preferred for at least a major proportion of the ungelatinised starch in the filling to be gelatinised on baking. Examples of suitable ungelatinised starches are corn starch, wheat starch, potato starch and rice starch. The said starches may be in the form of the pure starch, but are expediently added in the form of a starchy material. For example, corn starch may be added in the form of corn flour. In practice, the mixture may comprise for example from 25 to 220 parts, advantageously 120 to 200 parts, and preferably 150 to 200 parts, by weight ungelatinised starch per 100 parts by weight starch-based crumb material. It is possible, however, to make a satisfactory product comprising, for example, 25 to 55 parts by weight ungelatinised starch per 100 parts by weight starch-based crumb material.

Where the binding material consists wholly of pregelatinised starch or consists of a mixture of pregelatinised starch and ungelatinised starch, it may be desirable to reduce the amount of starch as compared with a recipe in which the binding material consists wholly of ungelatinised starch, the other ingredients present being the same.

The mixture may also comprise other ingredients, for example, one or more edible substances selected from flavour- or texture-enhancing substances, colourings, emulsifiers, and flavourings. It may be desirable for some of those ingredients, for example, flavourings, to be incorporated in the crumb material. The proportion of the mixture constituted by ingredients other than the crumb material (including any fat therein that is not intimately bound within the crumb material) , fat and binding material preferably does not exceed 25%, more preferably 15%, by weight, based on the total weight of the mixture. The mixture may be obtained by mixing the fat, ungelatinised starch and any other ingredients other than the granular crumb material, and combining the fatty mixture so obtained with the crumb material. The fatty mixture may be applied to the crumb material as a coating. Alternatively the mixture may be obtained by directly mixing together all of the ingredients of the mixture.

Advantageously, the filling constitutes from one quarter to two thirds, preferably one third to two thirds of the product, by weight, based on the combined weight of the filling and envelope. The baked envelope may have an average thickness (as measured between an inner surface and an outer surface of the envelope) of not more than 2 mm. The preferred average thickness will depend on the density of the envelope. Where the envelope is of relatively light texture, that is, where there has been substantial expansion of the dough on baking, it is preferred for the average thickness of the envelope to be from 1 to 2 mm. Where the envelope is relatively dense, that is, where there is little or substantially no expansion of the dough on baking, the average thickness of the envelope is preferably less than 1 mm. It will be appreciated that where, as described in more detail below, the envelope is formed by sealing together edges of one or more dough pieces, the sealed edges are to be disregarded for the purposes of determining the average thickness of the envelope.

The invention further provides a method of making a snack product comprising preparing a mixture of a starch- based crumb material, a fat and one or more binding materials selected from the group consisting of starches and starch derivatives; preparing a dough and forming the dough into a sheet; enclosing a portion of the mixture within an envelope made from the sheet of dough; and baking the envelope and the enclosed portion of the mixture to obtain a baked product comprising an envelope of cooked dough enclosing a filling, the moisture contents of the envelope of cooked dough being not greater than 10% by weight, based on the total weight of the envelope, and the moisture content of the filling being not greater than 10% by weight, based on the total weight of the filling. The moisture contents of the envelope and filling in the baked product may each advantageously be not greater than 7.5%, and preferably not greater than 5% by weight, based on the total weight of the said envelope and of the said filling, respectively. Advantageously, the moisture content of the mixture before baking is not greater than 20%, and preferably not greater than 15%, by weight, based on the total weight of the mixture. Moisture contents of 15% or less are preferred as the baking time needed to reduce the moisture content to 10% by weight or less is shorter than in the case of mixtures with higher moisture contents. In determining the moisture content of the mixture, it may be necessary to consider the moisture contents of the individual ingredients. For example, starch-based crumb materials made by extrusion cooking a mixture of starches, drying and crumbing the cooked mixture, typically have a moisture content of about 11%, by weight, and cornflour, which is a suitable ungelatinised starch, has a moisture content of about 13%, by weight. The moisture content may conveniently be determined using the method described after the Examples below.

The dough from which the sheet is formed may be any sheetable dough, but is advantageously a potato-based dough, for example, a dough comprising one or more materials selected from the group consisting of potato flakes, potato granules and potato starch. Where a potato-based dough is used, non-potato starches may also be present. For example, the dough may include a pregelled modified starch such as a modified waxy maize starch. The selection of dough ingredients and their relative proportions, having regard to the need for the dough to be sheetable and for the need to form an envelope that is sufficiently strong to hold the filling during baking, cooling and storage, will be routine matters for the person skilled in the art. The fat content of the envelope is preferably less than that of the filling. Thus, whilst the fat content of the filling mixture before baking is preferably not less than 7%, and more preferably not less than 10%, and especially not less that 25%, by weight, based on the total weight of the mixture, the fat content of the dough from which the envelope is formed is advantageously not greater than 5%, and more preferably not greater than 3.5%, by weight, based on the total weight of the dough. The dough may be formed into a sheet by any suitable method, for example, rolling the dough out by hand, or by using any mechanical sheeting means.

The amount of mixture used is advantageously so selected that, in the baked product, the baked mixture (that is, the filling) constitutes from one quarter to two thirds of the product, by weight, based on the combined weight of the filling and envelope.

The envelope may be formed from a single piece of sheet. In that case, the single piece may be folded about a portion of the mixture and the edges of the overlying portions of the piece sealed together along at least a part of their lengths to form a receptacle having an opening. In another suitable method the envelope may be formed from two pieces of dough sheet. One of the pieces is placed upon a flat surface, and a portion of the mixture is placed upon that piece, without covering the edges of the piece. The other piece, which is preferably essentially the same in shape and dimensions as the first piece, is placed over the first piece enclosing the mixture between the two pieces, and the edges of the two pieces are sealed together. The two pieces may be of any suitable shape, for example, triangular, rectangular or circular.

Alternatively several connected dough envelopes may be formed. A dough piece is placed on a flat surface and several portions of the mixture are placed on the piece, allowing sufficient distance between the portions of mixture and between the mixture and the dough edge to allow for sealing as described below. A second dough piece, having similar dimensions to the first piece, is placed over the first piece and the dough pieces are sealed to one another in the regions between the mixture portions and along their overlaid edges. The sealing may be so effected that lines of weakness are produced in the dough between the filling portions, for example lines of perforations may be formed along the sealed areas of the dough pieces between adjacent filling portions. The sealing of parts of an edge of a dough piece to one another or of edges of separate dough pieces to one another may conveniently be achieved, for example, by pressing the said parts or edges together firmly. In some cases, for example where the envelope is made from a dough of relatively low moisture content, it will be found convenient to use a suitable edible adhesive material, for example, a starch-based adhesive. The dough is preferably dockered before baking to reduce the possibility of blowing of the dough on baking. Dockering may be carried out before or after enclosing the filling mixture in the sheeted dough. It will be appreciated that, although certain methods of enclosing the mixture within an envelope are described herein, any other suitable method may also be used.

If desired, the baked product may be sprayed with oil after baking. The oil may contain a flavouring.

References herein to the fat content of the envelope are to be understood as referring to the fat content disregarding any oil that has been applied to the surface of the envelope after baking. The snack product of the invention may be a savoury snack product or a sweet snack product.

One form of baked product according to the invention will now be described in more detail with reference to the drawings of which Figure 1 is a perspective view of the baked product; and

Figure 2 is a cross sectional view of the baked product of Fig. 1.

With reference to Figure 1, the baked product 1 has an envelope 2. The envelope consists of two essentially triangular portions, having scalloped edges 3 of the same shape and dimensions which are sealed together along their edges to form the envelope 2. Inside the envelope is a filling 4, as may be seen from Figure 2. The filling 4 consists of the baked product of a mixture of a starch-based crumb material, fat, ungelatinised starch and a flavouring material, the crumb material being bound together by means of the fat and cooked starch. The envelope 2 consists of a relatively thin layer of cooked dough, which is of relatively crisp or crunchy texture compared to the filling 4. The filling 4 is perceived as a result of the presence of the fat, to have a relatively moist texture. It will be appreciated that the envelope 2 may be formed from dough portions of any desired configuration, for example, from square or rectangular dough portions. The following Examples illustrate the invention:

Example 1

Bite-sized savoury snack products were prepared as described in (a) to (d) below.

(a) A dough was made from the following ingredients:

Potato starch 200g

Potato flake 200g

Pregelled modified waxy maize starch 120g

Wheat flour 80g

Milk powder 30g

Oil 20g

Emulsifier 12.5g

Salt 5g

Beef fat flavouring 5g

Potato flavour 3g

Monosodium glutamate ig

Water 420mls

All the ingredients except the emulsifier, oil and the water were placed in a 3-speed Hobart mixer of capacity approximately 4.5 litres and mixed using a paddle blade at speed setting 1 for two minutes, the emulsifier and oil being added after about 1 minute. The water was then added and mixing was continued at the same speed for six minutes. A 250g portion of dough was placed on a flat surface and rolled out by hand using a Rondo sheeter to form a sheet having a thickness of about 1mm. Triangular pieces, each having three approximately equal edges of length 40mm were cut from the sheet using a preformed steel cutter. The weight of each piece was in the range of from 1.7 to 1.9g.

(b) A fat-based mixture was made from the following ingredients:

Corn starch (13% by weight moisture) 2383g Hard fat (28°C slip melting point) 1238g

Demineralised whey powder 934g

Salt 113g

Emulsifier 6.5g

The whey powder, corn starch, emulsifier and salt were placed in a 3-speed Hobart mixer of capacity approximately 4.5 litres and mixed using a paddle blade at speed 1 for ninety seconds. The fat (the slip melting point of which was determined according to the method described further below) was heated to 70°C and then added slowly whilst continuing mixing. Mixing was continued until the mixture was well blended (about 2 minutes) . The mixture so obtained was removed from the mixer and placed in a refining apparatus and refined at a temperature of 8°C and a pressure of 7.5 bar to obtain a refined fat cream powder. 300g of that fat cream powder was then added to a further lOOg of the melted hard fat in the Hobart mixer, and the ingredients mixed until a smooth textured fat cream was obtained.

(c) 60g of the smooth fat cream obtained in (b) were placed in a beaker with 50g of flavoured crumb material that had been obtained by extrusion cooking a starchy mixture containing wheat starch. All of the crumbs had particle sizes of greater than 0.4mm and less than 2.4mm as determined by placing the particles on a sieve having 2.4mm apertures and, after sieving, placing the material that passed through that sieve on a sieve having 0.4mm apertures, and again sieving, the said sieves conforming to British Standard No. 410. The fat cream and crumb material were blended manually until a substantially homogeneous mixture was produced.

(d) One of the triangular dough pieces obtained in (a) was placed on a flat surface and approximately 1.5g of the mixture obtained in (c) was placed centrally on the dough piece, the edges of the dough piece remaining uncovered. A second triangular dough piece was placed over the first, with the edges aligned with the edges of the first piece, and the edges of the pieces were pressed together firmly, enclosing the mixture. The envelope consisting of the dough pieces was dockered by puncturing with a pronged fork. Excess dough was cut away from the pressed edges, and the product so obtained was placed on a baking tray. A number of further products were similarly made, the amount of the portion of mixture enclosed being from 1.4 to 1.7g in each case. The products were placed on a wire mesh tray and baked in an oven at 350°F (177°C) for six minutes and then at 500"F (260"C) for from two to five minutes, the tray being turned (in a horizontal plane) approximately every 60 seconds, and each product being removed from the oven when it appeared cooked. Immediately after removal from the oven, the hot products were sprayed with an oil slurry comprising four parts by weight vegetable oil and one part by weight curry flavouring.

After cooling, the products were found to have a highly interesting texture, the filling being perceived, by virtue of its relatively high fat content, to be considerably moister than the envelope.

The moisture content of the baked dough outer and of the baked filling mixture, before application of the oil slurry, was determined using the method described below. The average moisture content was found to be as follows: Baked dough outer 3.4% Baked filling 4.0%

Example 2

Bite-sized savoury snack products were prepared as described in (a) to (c) below.

(a) A dough was made from the following ingredients:

Potato starch 200g

Potato flake 150g

Wheat flour 150g

Pregelled modified waxy maize starch 120g Full cream milk powder 30g

Oil 20g

Emulsifier 12.5g

Salt 5g

Water 380mls

All the ingredients except the emulsifier, oil and the water were placed in a 3-speed Hobart mixer of capacity approximately 4.5 litres and mixed using a paddle blade at speed setting 1 for four minutes, the emulsifier and oil being added after about two minutes. The water was then added and mixing was continued at the same speed for two minutes. A 250g portion of dough was placed on a flat surface and rolled out by hand using a Rondo sheeter to form a sheet having a thickness of about 0.6 to 0.7mm. Square pieces, each having edges of length 32mm were cut from the sheet using a preformed steel cutter. The weight of each piece was about lg.

(b) A fat-based mixture was made from the following ingredients:

Wheat flour 36.5g Flavoured crumb 32.2g

Oil (hardened rapeseed and palm oil blend, 28.9g slip point approx. 18°C) Cornflour 8.Og

Sunflower oil 1.8g

The ingredients were placed in a 3-speed Hobart mixer of capacity approximately 4.5 litres and mixed using a paddle blade at speed 1 until a substantially homogeneous mixture was produced (about 3 minutes) .

The flavoured crumb material had been obtained by applying to an unflavoured crumb material (which was the product of extrusion cooking a starchy mixture containing wheat starch) a flavouring composition in a fat-based carrier. The unflavoured crumb material used was Japanese-style breadcrumb. The composition of the flavoured crumb was as follows:

Unflavoured crumb 76.7% Fat 12.0%

Flavour 11.3%

The particle size distribution of the unflavoured crumb material and of the flavoured crumb material (determined using sieve analysis - the sieves conforming to British Standard No. 410) was as follows:

Sieve aperture size - % particles retained on sieve

1.7mm 1.18mm 710μm 250μm (Pass

Through 250μm) Flavoured 0.5 25.0 32.0 20.0 (22.5) Crumb

Unflavoured 0.5 32.5 40.0 22.0 (5.0) Crumb

(c) One of the square dough pieces obtained in (a) was placed on a flat surface and approximately 0.9g of the mixture obtained in (b) was placed centrally on the dough piece, the edges of the dough piece remaining uncovered. A second square dough piece was placed over the first, with its edges aligned with the edges of the first piece, and the edges of the pieces'were pressed together firmly, enclosing the mixture. The envelope consisting of the dough pieces was dockered by puncturing with a pronged fork. Excess dough was cut away from the pressed edges, and the product so obtained was placed on a baking tray. A number of further products were similarly made, the amount of the portion of the mixture enclosed being approximately 0.9g in each case. The total weight of the product before baking was 2g. The weight of the unbaked filling was 0.9g, and the weight of the unbaked dough envelope was l.lg. The products were placed on a wire mesh and first baked . in an oven at 350°F (177°C) for six minutes the products being turned (in a horizontal plane) after about three minutes and then baked at 450°F (232°C) for from two to five minutes, the products being turned about every 30 seconds. Each product was removed from the oven when it appeared cooked. Immediately after removal from the oven, the hot products were sprayed with an oil slurry comprising sunflower oil containing approximately 23% flavour. After baking, and before the oil slurry was applied, the weight of the dough envelope was found to be 0.9g and the weight of the filling was 0.8g. The total weight of the baked product (before the oil slurry was applied) was 1.7g.

The moisture content of the baked and unbaked dough envelope and of the baked and unbaked filling mixture was determined using the method described below. The average moisture content was found to be as follows:

Unbaked dough 31%

Unbaked filling 6.5%

Baked dough envelope (before the 3.8% application of oil slurry) Baked oiled dough envelope 3.5%

Baked filling 4.0 - 4.5%

Example 3

Bite-sized savoury snack products having an envelope made from a dough containing maize flour were prepared as described in (a) to (c) below.

(a) A dough was made with the following ingredients:

Pregelatinised maize flour 340g

Potato flake 150g Pregelled modified waxy maize starch 99g

Wheat flour 33g

Oil (sunflower oil) . 20g

Emulsifier 6g

Salt 4g Water 370mls

All the ingredients except the emulsifier, oil and the water were placed in a 3-speed Hobart mixer of capacity approximately 4.5 litres and mixed using a paddle blade at speed setting 1 for four minutes, the emulsifier and oil being added after two minutes. The water was then added and mixing was continued at the same speed for five minutes. A 250g portion of dough was placed on a flat surface and rolled out by hand using a Rondo sheeter to form a sheet having a thickness of about 0.6mm.

Square pieces, each having edges of length 32mm were cut from the sheet using a preformed steel cutter. The weight of each piece was in the range of from 1.2g to 1.3g.

(b) A fat-based mixture was made as in step (b) of Example 2 above.

(c) Filled envelopes were made as in step (c) of Example 2 above and were placed on a wire mesh and baked in a Dahlen oven (Static) in a first part of the oven at 500°F (260^βC) for six minutes and then in a second part of the oven at 350°F (177°C) for about four minutes. in the second baking phase (at 350°F (177°C)), the products were turned about every 30 seconds. If, at the end of the second baking phase, any products appeared to be still light in colour, those products were returned to the first part of the oven (at 500°F (260°C)) and removed when the products appeared cooked. Immediately after removal from the oven, the hot products were sprayed with an oil slurry comprising sunflower oil containing about 23% flavour.

Unbaked dough 35.1%

Unbaked filling 6.5% Baked dough envelope (before the 3.1% application of oil slurry)

Baked oiled dough envelope 2.7%

Baked filling 3.9%

Example 4 (a) A fat-based mixture is made as described in

Example 2 except that the wheat flour and the cornflour are replaced by 26.7g of pregelatinised potato starch (di-starch phosphate) , portions of the mixture are enclosed between pieces of sheeted dough and the products so obtained baked as described in Example 2 to give baked products in which the envelope and filling each have moisture contents of less than 5% by weight.

(b) A fat-based mixture is made as described in Example 2 except that the cornflour is omitted, the amount of wheat flour is reduced to 17.8g, and 26.7g of pregelatinised potato starch (di-starch phosphate) are used. In accordance with the method of Example 2, portions of the mixture are enclosed between pieces of sheeted dough and the products so obtained baked to give baked products in which the envelope and filling each have moisture contents of less than 5% by weight.

Whilst baked products obtained in accordance with Examples 4(a) and 4(b) are considered to be acceptable, they are less advantageous than those made in accordance with Examples 1 to 3.

The methods used for determining moisture content and slip melting point of fat will now be described. As will be seen both methods are standard, the first being one set out by the Food Research Association and the second being one set out in a British Standard.

Determination of moisture content (Food RA Analytical Methods Manual. 2nd Ed. - Moisture Determination by Oven Drying)

The percentage moisture content of a sample is determined by calculating a percentage loss in the weight of a number of samples when dried in an oven.

A sample is ground using a pestle and mortar or a mill. 5 to lOg of sample are introduced into a dried sample dish and the dish is placed in a fan oven heated to a temperature of 105°C (± 2°C) and left for three hours. The oven door is not opened at any time during the drying process. The dishes are removed from the oven. The sample is weighed immediately before and immediately after the heating step. The percentage moisture content of the sample is calculated as the loss in weight on drying as a percentage of the original sample weight. Determination of slip point of fat (British Standard 5841.3:1976)

A portion of the fat is melted in a receptacle that is closed, but not airtight, maintaining the temperature at not more than 10 Centigrade degrees above the point of complete fusion of the fat, and the melted fat is mixed throroughly by shaking. If the sample is not already clear, further heating is applied until it becomes clear, the sample being heated to a temperature not more than 10 Centigrade degrees above the point of complete fusion of the fat. While it is still liquid it is filtered through a dried open-texture paper in a glass funnel in a steam heated conical jacket. The filtrate is heated until it is bright and clear and, with the temperature about 10 Centigrade degrees above its melting point, a perfectly clean glass capillary tube is so inserted that a column of fat l±0.2cm long rises into it. The tube is uniformly thin-walled and open at both ends, and can have an internal diameter within the range of 1.1 to 1.3mm, an external diameter within the range of 1.4 to 1.7mm and its length may be within the range of 5 to 6cm. Cleaning of the glass tube may be effected, if necessary, by washing thoroughly with chromic acid mixture followed by distilled water and acetone, drying with hot air, and placing it in an air oven. The column of fat is solidified by bringing the tube and its contents to a temperature of 15°C as quickly as possible and keeping the tube at a temperature of 15 to 17°C for at least 16 hours. A mercury thermometer is attached to the tube with rubber bands, the column of fat being on a level with the mercury bulb of the thermometer. The thermometer is so suspended in the centre of a 500ml beaker containing 350ml aerated water at 15"C that the lower end of the fat column is 3cm below the surface of the water. The beaker is heated gently with thorough agitation of the water, the heating being controlled to increase the temperature at the rate of 2 Centigrade degrees per minute. When the fat starts to rise in the tube, the temperature of the water is recorded as the slip melting point.

Claims

1. A baked snack product comprising an envelope of cooked dough and a filling enclosed within said envelope, the filling comprising the baked product of a mixture comprising a starch-based crumb material, a fat and one or more binding materials selected from the group consisting of starches and starch derivatives, the envelope having a moisture content of not more than 10% based on the total weight of the envelope and the filling having a moisture content of not more than 10% based on the total weight of the filling.

2. A baked snack product as claimed in claim 1, in which the binding material is an ungelatinised starch.

3. A baked snack product as claimed in claim 1 or claim 2, in which the moisture contents of the envelope and the filling are each not more than 7.5% by weight.

4. A baked snack product as claimed in claim 3, in which the moisture contents of the envelope and the filling are each not more than 5% by weight.

5. A baked snack product as claimed in any one of claims 1 to 4, in which the filling is the baked product produced on baking a mixture comprising from 20 to 180 parts by weight fat per 100 parts by weight starch-based crumb material.

6. A snack product as claimed in claim 5, in which the filling is the baked product produced on baking a mixture comprising from 80 to 160 parts by weight fat per 100 parts by weight starch-based crumb material.

7. A snack product as claimed in any one of claims 1 to 6, in which the starch-based crumb material is breadcrumbs.

8. A snack product as claimed in any one of claims 1 to 7, in which the starch-based crumb material has been obtained by extrusion cooking a starch or a starch- containing material.

9. A snack product as claimed in any one of claims 1 to 8, in which the starch-based crumb material has been obtained by extrusion cooking or baking a mixture of starches, and drying and reducing to particles the cooked or baked mixture.

10. A snack product as claimed in any one of claims 1 to 9, in which the fat has a slip melting point of not more than 20°C.

11. A snack product as claimed in any one of claims 1 to 10, in which the fat is a fat blend comprising two or more fats selected from vegetable oils and hydrogenated vegetable oils.

12. A snack product as claimed in any one of claims 2 to 11, in which the filling is the baked product of a mixture comprising from 25 to 220 parts by weight ungelatinised starch per 100 parts by weight starch-based crumb material.

13. A snack product as claimed in claim 12, in which the filling is the baked product of a mixture comprising from 120 to 200 parts by weight ungelatinised starch per 100 parts by weight starch-based crumb material.

14. A snack product as claimed in any one of claims 1 to 13, in which the filling is the baked product of a mixture of which the proportion constituted by ingredients other than the crumb material, fat and binding material does not exceed 25% by weight, based on the total weight of the mixture.

15. A snack product as claimed in any one of claims 1 to 14, in which the envelope comprises a cooked potato- based dough.

16. A snack product as claimed in any one of claims 1 to 15, in which the filling constitutes from one quarter to two thirds of the product, by weight, based on the combined weight of the filling and envelope.

17. A snack product substantially as herein described with reference to and as illustrated by Figures 1 and 2.

18. A method of making a snack product comprising preparing a mixture of a starch-based crumb material, a fat and one or more binding materials selected from the group consisting of starches and starch derivatives; preparing a dough and forming the dough into a sheet; enclosing a portion of the mixture within an envelope made from the sheeted dough; and baking the envelope and the enclosed portion of the mixture to obtain a baked product comprising an envelope of cooked dough enclosing a filling, the moisture content of the envelope of cooked dough being not greater than 10% by weight, based on the total weight of the envelope, and the moisture content of the filling being not greater than 10% by weight, based on the total weight of the filling.

19. A method as claimed in claim 18, in which the binding material is an ungelatinised starch.

20. A method as claimed in claim 18 or claim 19, in which the moisture content of the mixture before baking is not greater than 20%, by weight, based on the total weight of the mixture.

21. A method as claimed in any one of claims 18 to 20, in which the mixture comprises from 20 to 180 parts by weight fat per 100 parts by weight starch-based crumb material.

22. A method as claimed in any one of claims 18 to 21, in which the mixture comprises from 25 to 220 parts by weight ungelatinised starch per 100 parts by weight starch-based crumb material.

23. A method as claimed in any one of claims 18 to 22, in which the starch-based crumb material is breadcrumbs.

24. A method as claimed in any one of claims 18 to 22, in which the starch-based crumb material has been obtained by extrusion cooking a starch or a starch- containing material.

25. A method as claimed in any one of claims 18 to 24, in which the starch-based crumb material has been obtained by extrusion cooking or baking a mixture of starches, and drying and reducing to particles the cooked or baked mixture.

26. A method as claimed in any one of claims 18 to 25, in which the fat has a slip melting point of not more than 20"C.

27. A method as claimed in any one of claims 18 to 26, in which the fat is a fat blend comprising two or more fats selected from vegetable oils and hydrogenated vegetable oils.

28. A method as claimed in any one of claims 18 to 27, in which the proportion of the mixture constituted by ingredients other than fat, binding material and starch- based crumb material does not exceed 25% by weight based on the total weight of the mixture.

29. A method as claimed in any one of claims 18 to 28, in which the dough from which the sheet is formed is a potato-based dough.

30. A method as claimed in any one of claims 18 to 29, in which the amount of mixture used is so selected that, in the baked product, the baked mixture constitutes from one quarter to two thirds of the product, by weight, based on the combined weight of the filling and envelope.

31. A method as claimed in any one of claims 18 to 30, in which the envelope is formed from a single piece of the dough sheet.

32. A method as claimed in any one of claims 18 to 31, in which two pieces are cut from a dough sheet, and the mixture is enclosed between the two pieces.

33. A method as claimed in any one of claims 18 to 32, in which the dough is dockered before baking.

34. A method of making a snack product substantially as described in any one of the Examples 1 to 4 herein.